Euornithes Sereno, 1998 non Stejneger, 1884
Official Definition- (Vultur gryphus <- Enantiornis leali, Cathayornis yandica) (Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022: Registration Number 553)
Other definitions- (Iberomesornis romerali + Passer domesticus) (modified
from Sanz and Buscalioni, 1992)
(Passer domesticus <- Sinornis santensis) (Sereno, online 2005; modified from Sereno, 1998)
(Passer domesticus <- Enantiornis leali) (modified from Longrich,
2009)
(Passer domesticus <- Cathayornis yandica) (Turner, Makovicky and Norell, 2012)
= Ornithurae sensu Gauthier and de Queiroz, 2001
Definition- (tail shorter than the femur and with an upturned and ploughshare-shaped
compressed pygostyle in the adult, composed of less than six segments, and shorter
than the less than eight free caudals homologous with Vultur gryphus)
= Euornithes sensu Sereno, 1998 (modified)
Definition- (Passer domesticus <- Sinornis santensis)
= Euornithes sensu Longrich, 2009
Definition- (Passer domesticus <- Enantiornis leali) (modified)
= Euornithes sensu
Turner, Makovicky and Norell, 2012
Definition- (Passer domesticus <- Cathayornis yandica)
= Ornithuromorpha sensu O'Connor, Wang and Hu, 2016
Definition- (Passer domesticus <- Enantiornis leali) (modified)
Diagnosis- (proposed) less than six caudal vertebrae fused into pygostyle; mobile scapulocoracoid articulation convex on scapular side; procoracoid process (absent in Patagopteryx and Apsaravis); coracoid not laterally convex (absent in Piscivornis, Bellulornis and Apsaravis); anterior edge of humeral head not concave in proximal view (absent in Patagopteryx and Ambiortus); lateral edge of manual phalanx II-1 deeply convex (absent in Schizooura, some Gansus and Xinghaiornis+Mengciusornis); metacarpal III does not extend much past metacarpal II (absent in Schizooura and Xinghaiornis); tarsometatarsus fused distally (absent in Archaeorhynchus and Xinghaiornis+Mengciusornis); pedal ungual I not strongly curved (absent in Tianyuornis).
Comments- Euornithes was first
used by Stejneger (1884; not Cope, 1889, contra Sereno, online 2005 and
Turner et al., 2012) as a superorder containing living birds besides
penguins. Sanz and Buscalioni (1992) later erected the homonym
Euornithes as a new subclass, "the most recent common ancestor of Iberomesornis
and Ornithurae (sensu Gauthier 1986 and Cracraft 1986) and all of its
descendants", which is equivalent to a modern Ornithothoraces. These
were both largely ignored. In the 1990s, birds intermediate
between enantiornithines and ornithurines began to be recognized, with
Chinese and BAND authors generally expanding the concept of Ornithurae
to include those taxa they studied (Chaoyangia, Gansus, Liaoningornis incorrectly, Songlingornis) while Western cladists created Ornithuromorpha for the taxa they studied (Patagopteryx, Vorona possibly incorrectly, Gargantuavis). Unfortunately, Ornithuromorpha was given node-based definitions dependant on Patagopteryx (and sometimes Vorona),
which had an uncertain placement relative to the numerous Chinese taxa
described in the early 2000s (yanornithids, hongshanornithids,
schizoourids, etc.). Thus Ornithuromorpha became an unstable
clade content-wise instead of the clade of birds closer to Aves than
Enantiornithes that most people wanted to refer to. One solution
was to use the expanded Ornithurae of Chinese authors, but formally
define it, which unfortunately led to an apomorphy-based definition
dependant on pygostyle anatomy (Gauthier and de Queiroz, 2001).
This was problematic because several relevant taxa (Patagopteryx, Vorona, Chaoyangia, the types of Yanornis and Archaeorhynchus)
don't preserve pygostyles, a classic example of why apomorphy-based
definitions should be avoided. Another solution proposed by
O'Connor et al. (2016) was to redefine Ornithuromorpha to be "The first
ancestor of Neornithes that is not also an ancestor of the
Enantiornithes, and all of its descendants." These definitions
were not used widely outside of Clarke's and O'Connor's works
respectively. Sereno (1998) had instead proposed Euornithes as a
new taxon with the definition "All ornithothoracines closer to
Neornithes than to Sinornis", followed by Longrich's (2009) definition "all birds closer to Passer than to Enantiornis" and
Turner et al.'s (2012) "Passer domesticus (Linnaeus, 1758) and all coelurosaurs closer to it than to Cathayornis yandica Zhou et al., 1992." These are all equivalent in modern topologies as Sinornis and Cathayornis
have been universally recognized as enantiornithines since 2000.
The resolution of what to call the clade was made by Benito et al.'s
(2022) use of Phylocode to establish the definition as "The largest
clade containing Vultur gryphus Linnaeus, 1758 (Aves or Neornithes) but not Enantiornis leali Walker, 1981 (Enantiornithes) and Cathayornis yandica
Zhou, Jin & Zhang, 1992 (Enantiornithes)", which is followed
here. As Benito et al. state, Phylocode Note 9.15A.2 says "In
order for two uses of identically spelled preexisting names to be
considered the same name rather than homonyms, one use must have been
derived from the other or both derived from a third use of the name. If
later uses of a name are not accompanied by a reference to an earlier
use, absence of any overlap in the compositions associated with
identically spelled names can be taken as evidence that they are
homonyms", and Sereno (1998) lists Euornithes as "new taxon" and states
it is "a taxon coined here" while also claiming to be "Unaware of Sanz
and Buscalioni (1992)" in 1998 (Sereno, online 2005) and was evidently
unaware of Stejneger's work even in 2005 as he cites Cope, 1889
instead. Thus Euornithes Stegnejer, 1884 and Euornithes Sanz and
Buscalioni, 1988 are homonyms of Euornithes Sereno, 1998 and the latter
should be cited as the proper author.
References-
Stejneger, 1884. Classification of birds. The Illustrated
Science Monthly. 2, 45-46.
Cope, 1889. Synopsis of the families of Vertebrata. The American Naturalist. 23, 849-877.
Sanz and Buscalioni, 1992. A new bird from the Early Cretaceous of Las Hoyas,
Spain, and the early radiation of birds. Palaeontology. 35, 829-845.
Sereno, 1998. A rationale for phylogenetic definitions, with application to
the higher-level taxonomy of Dinosauria. Neues Jahrbuch f�r Geologie und
Pal�ontologie Abhandlungen. 210(1), 41-83.
Gauthier and de Quieroz, 2001. Feathered dinosaurs, flying dinosaurs, crown
dinosaurs, and the name "Aves." In Gauthier and Gall (eds.). New Perspectives
on the Origin and Early Evolution of Birds: Proceedings of the International
Symposium in Honor of John H. Ostrom. Peabody Museum of Natural History. 7-41.
Sereno, online 2005. Stem Archosauria - TaxonSearch. http://www.taxonsearch.org/dev/file_home.php
[version 1.0, 2005 November 7]
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Turner, Makovicky and Norell, 2012. A review of dromaeosaurid systematics and
paravian phylogeny. Bulletin of the American Museum of Natural History. 371,
1-206.
O'Connor, Wang and Hu, 2016. A new ornithuromorph (Aves) with an elongate rostrum
from the Jehol Biota, and the early evolution of rostralization in birds. Journal
of Systematic Palaeontology. 14(11), 939-948.
Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022. Forty new specimens of Ichthyornis provide unprecedented insight into the postcranial morphology of crownward stem group birds. PeerJ. 10:e13919.
unnamed probable Euornithes (Morrison, Dyke and Chiappe, 2005)
Late Campanian, Late Cretaceous
Northumberland Formation of the Nanaimo Group, British Columbia, Canada
Material- (RBCM.EH2005.003.0001.C) distal ulna (Morrison, Dyke and Chiappe, 2005)
(RBCM.EH2005.003.0001.D) distal ulna (Morrison, Dyke and Chiappe, 2005)
(RBCM.EH2005.003.0001.E) tibiotarsus (95 mm) (Morrison, Dyke and Chiappe, 2005)
(TMP 1999.081.0001) carpometacarpus (57 mm) (Dyke, Wang and Kaiser, 2011)
Comments- These were
tentatively referred to Ornithurae by Morrison et al.
(2005) and (in the case of the carpometacarpus) Dyke et al. (2011).
Note that other ornithurine specimens described in these publications
are here placed in Aves- tarsometatarsi RBCM.EH2005.003.0001.A and
RBCM.EH2005.003.0001.B, and coracoid RBCM.EH2008.011.01120 that was
later made part of the holotype of Maaqwi.
References- Morrison, Dyke and Chiappe, 2005. Cretaceous fossil birds
from Hornby Island (British Columbia). Canadian Journal of Earth Sciences. 42(12),
2097-2101.
Dyke, Wang and Kaiser, 2011. Large fossil birds from a Late Cretaceous marine
turbidite sequence on Hornby Island (British Columbia). Canadian Journal of
Earth Sciences. 48(11), 1489-1496.
undescribed Euornithes (DePalma, 2010)
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, South Dakota, US
Material- (multiple individuals, at least two taxa) over twenty elements
including incomplete mandibles and coracoid
twelve cervical vertebrae, nine dorsal vertebrae, fragmentary synsacrum, scapula,
coracoid, partial pelves, phalanx I-1, pedal ungual I, tarsometatarsus
Comments- This material is in preparation for description and referred
to Ornithurae by DePalma (2010).
Reference- DePalma, 2010. Geology, taphonomy, and paleoecology of a unique
Upper Cretaceous bonebed near the Cretaceous-Tertiary boundary in South Dakota.
Masters thesis, University of Kansas. 227 pp.
undescribed euornithine (Galton, Dyke and Kurochkin, 2009)
Late Albian, Early Cretaceous
Cambridge Greensand, England
Material- (Booth Museum coll?) humerus
Comments- Galton et al. (2009) note an ornithurine humerus from the Cambridge
Greensand, though which definition of Ornithurae they use is uncertain. This
may be one of the seven bird elements from the Booth Museum (mentioned as "Enaliornis
and Aves incertae sedis, including ends of humeri") to be described by
Galton (in prep.).
References- Galton, Dyke and Kurochkin, 2009. Re-analysis of Lower Cretaceous
fossil birds from the UK reveals an unexpected diversity. Journal of Vertebrate
Paleontology. 29(3), 102A.
Galton, in prep. Additional bird bones (Hesperornithiformes Enaliornis
and Aves incertae sedis) from the Early Cretaceous of England. Revue Paleobiologie.
unnamed euornithine (Hurum, Roberts, Dyke, Grundv�g, Nakrem, Midtkandal, Śliwińska and Olaussen, 2016)
Early-Mid Albian, Early Cretaceous
Zillerberget Member, Carolinefjellet Formation, Norway
Material- (PMO 228.582) femur (35 mm)
Comments- This was discovered
in 1962 and tentatively assigned to ?Avialae. Hartman et al.
(2019) recovered it as a euornithine sister to Schizooura, but with only the femur known a more exact position than basal Euornithes is not advocated for here.
References- Hurum, Roberts,
Dyke, Grundv�g, Nakrem, Midtkandal, Śliwińska and Olaussen, 2016. Bird
or maniraptoran dinosaur? A femur from the Albian strata of
Spitsbergen. Palaeontologia Polonica. 67, 137-147.
unnamed euornithine (Nesov, 1984)
Early Cenomanian, Late Cretaceous
Khodzhakul Formation, Uzbekistan
Material- (TsNIGRI 57/11915) distal tarsometatarsus(?)
Comments- This was discovered in 1975 and briefly described and illustrated
by Nesov (1984) as a possible distal tarsometatarsus of an aquatic bird. Nesov
identified it as coming from the Beshtyuba Formation, but later (1992) determined
that locality (Cholpyk or Tcelpyk) belongs to the Khodzhakul Formation instead.
If it is indeed a fused distal tarsometatarsus, it is probably an euornithine.
Nessov notes metatarsal II ends more proximally than III and IV.
References- Nesov, 1984a. Pterozavry i ptitsy pozdnego mela Sredney Azii. Paleontologicheskii Zhurnal. 1, 47-57.
Nesov, 1984b. Upper Cretaceous pterosaurs and birds from central Asia. Paleontological Journal. 1, 38-49.
Nessov, 1992. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478..
unnamed euornithine (Nesov, 1984)
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Materal- (TsNIGRI 44/11915; paratype of Zhyraornis kashkarovi) proximal scapula
Comments- This scapula was originally a paratype of Zhyraornis kashkarovi
(Nesov, 1984). Kurochkin (1996) later noted the acromion and glenoid showed
"a certain similarity" to enantiornithines, but could not refer to
to Zhyraornis itself (which he regarded as an enantiornithine). The elongate
anteriorly projecting acromion and limited coracoid articulation indicates it
is ornithothoracine, while Nesov noted the coracoid articular surface was weakly
convex, unlike enantiornitines. Patagopteryx differs in having a transversely
expanded acromion which is also ventrally constricted, distally flat and dorsally
angled. That of Archaeorhynchus is smaller and more separated from the
scapula ventrally. That of Yixianornis is slightly more slender and dorsally
projected, and is separated ventrally from the bulbous coracoid tubercle. Ambiortus'
acromion is different in being dorsoventrally compressed and having a dorsal
tubercle, though the length and low coracoid tubercle are roughly similar. Apsaravis
has a more elongate and hooked acromion, though the coracoid tubercle is similarly
low. The scapulae of hesperornithines are highly reduced, while Ichthyornis
has an apomorphically reduced acromion. Iaceornis' is narrower and hooked,
with a bulbous coracoid tubercle. Those of Aves sensu stricto are generally
dorsoventrally compressed. TsNIGRI 44/11915 is here referred to Euornithes
incertae sedis, though it may belong to Zhyraornis.
References- Nesov, 1984a. Pterozavry i ptitsy pozdnego mela Sredney Azii. Paleontologicheskii Zhurnal. 1, 47-57.
Nesov, 1984b. Upper Cretaceous pterosaurs and birds from central Asia. Paleontological Journal. 1, 38-49.
Kurochkin, 1996. A new enantiornithid of the Mongolian Late Cretaceous, and
a general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy
of Sciences, special issue. 50 pp.
unnamed euornithine (Nessov, 1992)
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Material- (ZIN PO 4605) proximal coracoid
Comments- Nessov (1992a) noted a coracoid with a "deep, round scapular
facet", which seems to be the one later figured by him as possibly an ichthyornithiform
(Nessov, 1992b). Note the specimen number is the same as a distal coracoid now
referred to Abavornis species and labeled Aves in the same figure. Compared
to Ichthyornis, it has a more proximolateral-distomedially oriented scapular
cotyla, and a more laterally and less ventrally angled acrocoracoid which is
dorsoventrally flatter. The concave scapular cotyla does indicate referral to Euornithes however.
References- Nessov, 1992a. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478.
Nessov, 1992b. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
unnamed euornithine (Nessov, 1992)
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Material- (ZIN PO 3434b) distal tarsometatarsus
Comments- This specimen was listed as Aves indet. by Nessov (1992),
but can be identified as a euornithine by the high degree of distal fusion,
including a distal vascular foramen. It is not hesperornithine, since metatarsal
IV is less robust than III.
Reference- Nessov, 1992. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478.
unnamed probable euornithine (Nessov, 1992)
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Material- (ZIN PO 4607) dorsal vertebra (7 mm)
Comments- Nessov (1992a) noted an ichthyornithiform vertebra discovered
in 1989, which seems to be a dorsal vertebra (ZIN PO 4607) later figured by
him as Ichthyornis sp. (Nessov, 1992b). It is roughly similar to Ichthyornis,
but the dorsals of that taxon are not diagnostic, and ZIN PO 4607 could come
from another related taxon as well. It is from an avebrevicaudan due to its
large lateral central fossae, probably an ornithothoracine based on its age.
It is not an enantiornithine, as the parapophyses are anteriorly placed, and
can be excluded from Hesperornithes and Aves sensu stricto due to its amphicoely.
References- Nessov, 1992a. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478.
Nessov, 1992b. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
unnamed possible euornithine (Clarke and Norell, 2004)
Early Maastrichtian, Late Cretaceous
Tsaagan Khushu, Nemegt Formation, Mongolia
Material- (IGM 100/1310) proximal tibiotarsus
Comments- Diuscovered in 2001,
IGM 100/1310 was described by Clarke and Norell (2004) and recovered as
a member of Ornithurae using Clarke's avialan
matrix. This is based on the presence of a medial cnemial crest,
which is also known in more basal euornithines as well as a few
enantiornithines (Hollanda, Gobipteryx, Alexornis) and some alvarezsaurids (though it differs from the contemporaneous Mononykus in the larger anterior cnemial crest, tuberculated medial scar and other proportions).
Reference-
Clarke and Norell, 2004. New avialan remains and a review of the known avifauna
from the Late Cretaceous Nemegt Formation of Mongolia. American Museum Novitates.
3447. 12 pp.
unnamed euornithine (Hou, Martin, Zhou and Feduccia, 1996)
Early Albian, Early Cretaceous
Boluochi, Jiufotang Formation, Liaoning, China
Material- (IVPP V9937) partial tibia, partial fibula,
phalanx I-1 (~5 mm), pedal ungual I (~3 mm), distal tarsometatarsus,
phalanx II-1 (~9 mm), phalanx II-2 (~7 mm), pedal ungual II (~6 mm),
phalanx III-1 (~9 mm), phalanx III-2 (~7 mm), phalanx III-3 (~6 mm),
pedal ungual III (~7 mm), phalanx IV-? (~6 mm), phalanx IV-? (~5 mm),
phalanx IV-4 (~5 mm), pedal ungual IV (~4 mm)
Comments- First mentioned as "a partial foot" referred to Chaoyangia
by Hou et al. (1996) and used in their skeletal reconstruction. The
specimen number was listed as a referred specimen by Zhou and Hou
(2002) without detail, and it was finally described and illustrated by
O'Connor and Zhou (2013) as Euornithes indet. (their Ornithuromorpha). A position in
Euornithes is suggested based on the distally fused metatarsus.
References-
Hou, Martin, Zhou and Feduccia, 1996. Early adaptive radiation of birds: evidence
from fossils from northeastern China. Science. 274, 1164-1167.
Zhou and Hou, 2002. The discovery and study of Mesozoic birds in China. In Chiappe
and Witmer (eds.). Mesozoic Birds - Above the Heads of Dinosaurs. University
of California Press. 160-183.
O'Connor and Zhou (online 2012), 2013. A redescription of Chaoyangia beishanensis (Aves)
and a comprehensive phylogeny of Mesozoic birds. Journal of Systematic Palaeontology.
11(7), 889-906.
Euornithes indet. (Harris, Lamanna, Li and You, 2009)
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Material- ?(IVPP V26194;
Ornithuromorpha indet. A) posterior skull, sclerotic ossicles,
posterior mandibles(?), altantal neural arch, axis (5.42 mm), third
cervical vertebra (3.10 mm), fourth cervical vertebra (4.59 mm), fifth
cervical vertebra (5.17 mm), sixth cervical vertebra (5.66 mm), seventh
cervical vertebra, eighth cervical vertebra, partial ninth cervical
vertebra
(IVPP V26195; Ornithuromorpha indet. B) posterior braincase, altantal neural arch, axis, third cervical vertebra (3.28
mm), fourth cervical vertebra (3.41 mm), fifth cervical vertebra (4.47
mm), sixth cervical vertebra, seventh cervical vertebra (5.54 mm),
eighth cervical vertebra (5.46 mm), partial ninth cervical vertebra
?(IVPP V26196; Ornithuromorpha indet. C) posterior skull, posterior
mandibles, altas, axis, third cervical vertebra (4.29
mm), fourth cervical vertebra (5.22 mm), fifth cervical vertebra (6.21
mm), sixth cervical vertebra (5.89 mm), seventh cervical vertebra,
eighth cervical vertebra, ninth cervical vertebra, tenth cervical
vertebra (4.86 mm), first dorsal vertebra (5.09 mm), second dorsal
vertebra, third dorsal vertebra, fourth dorsal vertebra, fifth dorsal
vertebra, dorsal rib fragment
Comments- IVPP V26194 was initially mentioned by Harris et al. (2009) as likely belonging to Gansus,
noted as the posterior cranial half exposed in dorsal view.
O'Connor et al. (2021, 2022) described it as an indeterminate
euornithine (ornithuromorph in their usage), as it was not easily
comparable to probable Gansus
skull IVPP V26199 which is preserved in ventral view and only the first
three cervicals. O'Connor et al. used O'Connor's bird analysis to
recover it as an avialan in a trichotomy with Jeholornis
and Pygostylia, which they attributed "to the limited number of
morphological characters that could be confidently scored into the
current matrix." Adding it to Hartman et al.'s maniraptoromorph
analysis places it in Enantiornithes, but only a single step moves it
to Euornithes. Among Xiagou taxa, it takes 0 steps to be Avimaia, 1 step to be Dunhuangia or Feitianius, 3 steps to be Qiliania, 4 steps to be Gansus, Meemannavis or Yumenornis, 5 steps to be Changmaornis, and 8 steps to be Jiuquanornis. Cervical proportions indicate it is not Brevidentavis.
IVPP V26195 was also first mentioned by Harris et al. (2009) as a likely Gansus
specimen, as the one which "preserves a caudal fragment of the
braincase that exhibits an intricate series of curvilinear impressions
that may correspond to portions of the brain or neural
vasculature." O'Connor et al. (2021, 2022) also described
this as an indeterminate euornithine (ornithuromorph) as only the first three
cervicals are comparable to Gansus, and used O'Connor's bird analysis to recover it in a polytomy with Schizooura, Xinghaiornis and Zhongjianornis
(note the trees in their figure 9 are majority rule and implied
weighting). In Hartman et al.'s matrix it resolves as an avian,
and takes 1 more step to be Changmaornis, Gansus, Meemannavis or Yumenornis, 3 steps to be Avimaia, Dunhuangia or Feitianius, 4 steps to be Jiuquanornis, and 5 steps to be Qiliania. As for the above specimen, cervical proportions indicate it is not Brevidentavis.
IVPP V26196 is the last specimen noted by Harris et al. (2009) as probably Gansus,
one of the "caudal halves of crania" preserved in right lateral
view. Again, O'Connor et al. (2021, 2022) describe this as
an indeterminate euornithine (ornithuromorph), which is again difficult to compare to
the Gansus specimen preserved
in ventral view. They recovered this specimen in a polytomy with
other euornithines (again, the more precise positions in their figure 9
are due to majority rule consensus and implied weighting). In
Hartman et al.'s matrix it resolves as an enantiornithine, taking no
steps to be Avimaia, 1 step to be Dunhuangia, Feitianius or Meemannavis, 2 steps to be Qiliania, Gansus or Yumenavis, 3 to be Changmaornis, 4 to be Brevidentavis and 6 to be Jiuquanornis.
References- Harris, Lamanna, Li and You, 2009. Avian cranial material and cranial cervical
vertebrae from the Lower Cretaceous Xiagou Formation of Gansu Province, China.
Journal of Vertebrate Paleontology. 29(3), 111A.
O'Connor, Lamanna, Harris, Hu, Bailleul, Wang and You, 2021. First
avian skulls from the Lower Cretaceous Xiagou Formation, Gansu, China.
The Society of
Vertebrate Paleontology Virtual Meeting Conference Program, 81st Annual
Meeting. 196.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
(online 2021). Avian skulls represent a diverse ornithuromorph fauna
from the
Lower Cretaceous Xiagou Formation, Gansu Province, China. Journal of
Systematics and Evolution. 60(5), 1172-1198.
undescribed Euornithes (Gao, Li, Wei, Pak and Pak, 2009)
Barremian-Albian, Early Cretaceous
Sinuiju Series, North Korea
Comments-
Gao et al. (2009) report "even more advanced ornithurine birds" from
the Sinuiju Series, though these remain undescribed. It is
assumed Gao et al. use Martin's concept of Ornithurae that is
equivalent to Euornithes.
References- Gao, Li, Wei, Pak and Pak, 2009. Early Cretaceous birds and
pterosaurs from the Sinuiju series, and geographic extension of the Jehol biota
into the Korean peninsula. Journal of the Paleontological Society of Korea.
25(1), 57-61.
unnamed possible euornithine (Buffetaut, Dyke, Suteethorn and Tong, 2005)
Late Barremian, Early Cretaceous
Kalasin 3, Sao Khua Formation, Thailand
Material- (K3-1) distal humerus
Comments-
This was discovered in 1992 and "may be an early ornithurine" according to Buffetaut et al. (2005). That was based on two
characters, the transversely oriented dorsal condyle and the brachial
fossa, which are both present in many theropods. It is provisionally
listed
here pending further study.
Reference- Buffetaut, Dyke, Suteethorn and Tong, 2005. First record of
a fossil bird from the Early Cretaceous of Thailand. Comptes Rendus Palevol. 4(8), 681-686.
undescribed possible euornithine (Close and Vickers-Rich, 2009)
Aptian, Early Cretaceous
Wonthaggi Formation of the Strzelecki Group, Victoria, Australia
Material- cervical vertebra
Comments-
This was mentioned as "a small, heterocoelous cervical vertebra, which
has been tentatively identified as an ornithuromorph." It is here
placed in Euornithes as Ornithuromorpha was often used as a rough
synonym at the time, and taxa basal to Patagopteryx (e.g. Jianchangornis, Archaeorhynchus) also have fully heterocoelous cervicals.
Reference- Close and Vickers-Rich, 2009. Australia's Mesozoic birds:
New material from the Early Cretaceous of Victoria. Journal of Vertebrate Paleontology.
29(3), 80A.
Jianchangornis Zhou, Zhang
and Li, 2009b
= "Jianchangornis" Zhou, Zhang and Li, 2009a
J. microdonta Zhou, Zhang and Li, 2009b
= "Jianchangornis microdonta" Zhou, Zhang and Li, 2009a
Early Albian, Early Cretaceous
Jianchang, Jiufotang Formation, Liaoning, China
Holotype- (IVPP V16708) (820 g, subadult) incomplete skull (72 mm), nine
sclerotic plates, mandibles (one partial), hyoid, eight cervical vertebrae,
seven dorsal vertebrae, eleven dorsal ribs, four gastralia, synsacrum (34 mm),
pygostyle (5.5 mm), scapulae (53, ~47mm), coracoids (~30, 32 mm), furcula, sternum,
humeri (75, 76 mm), radii (81, 78 mm), ulnae (82, 83 mm), scapholunare, pisiform, semilunate
carpals, metacarpals I (10, 10 mm), phalanges I-1 (~25, 29 mm), manual unguals
I (~9, ~9 mm), metacarpals II+III (mcII 34, 33 mm, mcIII ~32, 36 mm), phalanges
II-1 (~20, ~18 mm), phalanges II-2 (~16, ~16 mm), manual unguals II (~4.5, ~6
mm), manual ungual III (~5.5 mm), ilia (38 mm), pubes (~51 mm), femora (59,
60 mm), tibiotarsi (75, 76 mm), fibulae (one proximal; 26 mm), pedal ungual
I (~5.5 mm), tarsometatarsi (one incomplete; ~35, 37 mm), phalanx II-1 (12 mm),
phalanges II-2 (11 mm), pedal unguals II (~6 mm), phalanges III-1 (15 mm), phalanges
III-2 (11 mm), phalanges III-3 (10 mm), pedal ungual III (~7 mm), phalanx IV-1,
phalanges IV-2 (8 mm), phalanges IV-3 (6 mm), phalanges IV-4 (7 mm), pedal ungual
IV (~6 mm), feathers, fish fragments
Diagnosis- (after Zhou et al., 2009) at least 16 small, conical dentary
teeth; strongly curved scapula; robust U-shaped furcula; robust and wide metacarpal
I; manual digit I extends beyond metacarpal II; humerus+ulna+carpometacarpus
/ femur+tibiotarsus+tarsometatarsus ratio ~1.1.
Comments- This specimen was briefly described in an abstract (Zhou et
al., 2009a) before being named and fully described later that year (Zhou et
al., 2009b), though the former use is a nomen nudum due to ICZN Article 9.9.
Including it in a version of Clarke's analysis, the authors found a basal euornithine
polytomy consisting of Vorona, Archaeorhynchus, Jianchangornis, Hongshanornis,
Patagopteryx, songlingornithids and more derived birds.
References- Zhou, Zhang and Li, 2009a. A new basal ornithurine bird from
the Lower Cretaceous of China. Journal of Vertebrate Paleontology. 29(3), 207A.
Zhou, Zhang and Li, 2009b. A new basal ornithurine bird (Jianchangornis microdonta
gen. et sp. nov.) from the Lower Cretaceous of China. Vertebrata PalAsiatica.
47(4), 299-310.
unnamed clade (Archaeorhynchus + Aves)
Diagnosis- (proposed) medial cnemial crest (absent in patagopterygiforms).
Schizoouridae Zelenkov in Zelenkov and Kurochkin, 2015
Definition- (Schizooura lii <- Apsaravis ukhaana) (Zelenkov and Kurochkin, 2015)
Other definitions- (Mengciusornis dentatus, Schizooura lii <- Jianchangornis microdonta, Bellulornis rectusunguis) (modified after Wang et al., 2019 online)
Diagnosis- (proposed) toothless premaxilla (also in ambiortiforms, Xinghaiornis and Odontornithes+Carinatae); toothless maxilla (also in Xinghaiornis+Mengciusornis and Aves); nasal contacts antorbital fenestra (also in toothless dentary (also in Odontornithes+Carinatae); Xinghaiornis+Mengciusornis, Apsaravis and Aves); dentary symphysis <45 degrees in lateral view (also in Juehuaornis and Xinghaiornis).
Comments- Schizoouridae was
named by Zelenkov in a Russian book chapter by Zelenkov and Kurochkin
(2015) as a sister taxon to Apsaravidae in Euornithes (his
Ornithurae). This was not based on a numerical phylogenetic
analysis and a pairing of Schizooura and Apsaravis has not been recovered to my knowledge in such analyses. However, as Apsaravis is near universally found to be closer to Aves than Schizooura their phylogenetic definition serves as a name for whichever taxa group with Schizooura to the exclusion of Aves.
Wang et al. (2019 online) were unaware of Zelenkov's work so tried to
create the name Schizoouridae themselves. They intended it to
include Schizooura and Mengciusornis, but the latter falls out closer to Bellulornis
using the Hartman et al. maniraptoromorph matrix, so that their
phylogenetic definition self destructs. At least six steps are
necessary to make the definition valid.
References- Zelenkov and Kurochkin, 2015. Class Aves. In Kurochkin, Lopatin and
Zelenkov (eds.). Fossil vertebrates of Russia and adjacent countries.
Part 3. Fossil Reptiles and Birds. GEOS. 86-290.
Wang, O'Connor, Zhou and Zhou, 2020 (online 2019). New
toothed Early Cretaceous ornithuromorph bird reveals intraclade
diversity in pattern of tooth loss. Journal of Systematic
Palaeontology. 18(8), 631-645.
Schizooura Zhou, Zhou and O'Connor,
2012
= "Eoornithura" O'Connor and Zhou, 2013
S. lii Zhou, Zhou and O'Connor, 2012
= "Eoornithura lii" O'Connor and Zhou, 2013
Early Albian, Early Cretaceous
Jianchang, Jiufotang Formation, Liaoning, China
Holotype- (IVPP V16861) skull (50.01 mm), mandibles, eleven cervical vertebrae,
posterior six dorsal vertebrae, partial dorsal ribs fused to uncinate process,
gastralia, synsacrum, eight caudal vertebrae, pygostyle (6.45 mm), scapulae (one
partial; 50 mm), coracoids (27.47 mm), furcula, sternum, sternal ribs, humeri (56.40
mm), radii (57.32 mm), ulnae (65.90 mm), scapholunares, pisiforms, metacarpals I (6.67 mm),
phalanges I-1 (one partial; 11.77 mm), manual unguals I (3.83 mm), carpometacarpi
(31.14 mm; mcII 22, mcIII 23 mm), phalanges II-1 (one incomplete; 14.41 mm), phalanges
II-2 (14.70 mm), manual unguals II (2.16 mm), phalanx III-1 (5.52 mm), ilia (one incomplete,
one partial), incomplete pubes (~40.94 mm), ischium, femora (49.00 mm), tibiotarsi
(61.17 mm), partial fibula, metatarsals I, phalanges I-1 (4.63 mm), pedal unguals
I (3.25 mm), tarsometatarsi (35.60 mm), phalanges II-1 (9.65 mm), phalanges II-2 (7.64
mm), pedal unguals II (5.20 mm), phalanges III-1 (9.36 mm), phalanges III-2 (7.72 mm),
phalanges III-3 (6.50 mm), pedal unguals III (6.25 mm), phalanx IV-1 (5.92 mm), phalanges
IV-2 (4.99 mm), phalanges IV-3 (4.34 mm), phalanges IV-4 (4.31 mm), pedal unguals IV
(5 mm), body feathers, remiges, retrices
Diagnosis- (after Zhou et al., 2012) toothless; dorsal premaxilla process
contacts frontals; jugal slender; robust, V-shaped furcula with short hypocleidium;
robust humerus with large deltopectoral crest that extends ~50% of humeral length;
(humerus+ulna+mcII)/(femur+tibiotarsus+tarsometatarsus) ratio ~1.01; tarsometatarsotibiotarsal
ratio high (0.58).
Comments- O'Connor and Zhou (2013; first online in 2012) used the name
"Eoornithura lii" in their supplementary information, which based
on its absence in the main paper where Schizooura liiis
present, and similarity to that name, is near certainly an early
name for the taxon. Zhou et al. (2012) list the pygostyle length
as 20 mm, but this includes all eight associated distal vertebrae,
while Wang et al. (2017) lists it as 6.45 mm, presumably only including
the fused distal three elements. Wang et al. (2020) determined
"CT scanning clearly shows that the upper and lower jaws of Schizooura are toothless" and provided revised measurements.
References- Zhou, Zhou and O'Connor, 2010. A new toothless ornithurine
bird from the Lower Cretaceous of China. Journal of Vertebrate Paleontology.
Program and Abstracts 2010, 192A.
Zhou, Zhou and O'Connor, 2012. A new basal beaked ornithurine bird from the
Lower Cretaceous of Western Liaoning, China. Vertebrata PalAsiatica. 50(1),
9-24.
O'Connor and Zhou, 2013. A redescription of Chaoyangia beishanensis (Aves)
and a comprehensive phylogeny of Mesozoic birds. Journal of Systematic Palaeontology.
11(7), 889-906.
Wang, O'Connor, Pan and Zhou, 2017. A bizarre Early Cretaceous
enantiornithine bird with unique crural feathers and an ornithuromorph
plough-shaped pygostyle. Nature Communications. 8:14141.
Wang, O'Connor, Zhou and Zhou, 2020 (online 2019). New toothed Early
Cretaceous ornithuromorph bird reveals intraclade diversity in pattern
of tooth loss. Journal of Systematic Palaeontology. 18(8), 631-645.
Archaeorhynchus Zhou and
Zhang, 2006
= "Archaeorhychus" Zhou and Zhang, 2005 online
A. spathula Zhou and Zhang, 2006
"Archaeorhynchus spathula" Zhou and Zhang, 2005 online
Late Valanginian-Middle Aptian, Early Cretaceous
Yixian, Yixian Formation, Liaoning, China
Holotype-
(IVPP V14287) (270 g, subadult) skull, sclerotic plates, mandibles, ten
cervical vertebrae, several dorsal vertebrae, dorsal ribs, uncinate
processes, gastralia, sacrum, nine caudal vertebrae, scapulae (46 mm),
coracoids (20 mm), furcula, sternum, sternal ribs, humeri (54 mm),
radii (56 mm), ulnae (57 mm), scapholunare, pisiform, carpometacarpi
(27mm; mcI 6, mcII 25, mcIII 24 mm), phalanx I-1 (10.5 mm), phalanx
II-1, phalanx II-2, manual ungual, ilia, pubes (37 mm), ischia (~20
mm), femora (37 mm), tibiae (43 mm), fibulae, astragali, metatarsal I,
tarsometatarsus (20 mm; one partial), thirteen pedal phalanges, seven
pedal unguals, body feathers, remiges, gastroliths
Late Valanginian-Middle Aptian, Early Cretaceous
Linyuan, Yixian Formation, Liaoning, China
Referred- (IVPP V20312) (adult) partial skull, mandibles, hyoid, eight
postaxial cervical vertebrae, four dorsal vertebrae, several dorsal ribs, four
caudal vertebrae, pygostyle (5.40 mm), scapulae (one incomplete), coracoids, furcula,
sternum, humeri (59.1 mm), radii (60.3 mm), ulnae (61.3 mm), pisiform, carpometacarpi
(28.3 mm, mcI 7.2 mm), phalanges I-1, manual ungual I, partial pubes, distal
ischia, incomplete femora, tibiotarsi (44.9 mm), fibulae, tarsometatarsi (21.6
mm), phalanges II-1, phalanges II-2, pedal unguals II, phalanges III-1, phalanges
III-2, phalanges III-3, pedal unguals III, phalanges IV-1, phalanges IV-2, phalanges
IV-3, phalanges IV-4, pedal unguals IV, gastroliths (Wang and Zhou, 2017)
Early Albian, Early Cretaceous
Jianchang, Jiufotang Formation, Liaoning, China
(IVPP V17075) (subadult) incomplete skull, partial sclerotic rings,
hyoid, atlantal arches, axis, seven cervical vertebrae, cervical ribs,
three posterior dorsal vertebrae, dorsal ribs, gastralia, fused first
to fourth sacral vertebrae, fifth to seventh sacral vertebrae, seven
caudal vertebrae, pygostyle, incomplete scapulae (46 mm), partial
coracoids (20 mm), furcula, partial sternum, sternal ribs, humeri (one
incomplete; 53 mm), radii (one partial; 55 mm) ulnae (58 mm),
scapholunares, pisiforms, (carpometacarpus 28.5 mm) semilunate carpals,
distal carpal III, metacarpals I (6 mm), phalanges I-1 (10 mm), manual
unguals I (6 mm), metacarpals II (25 mm), phalanges II-1 (12 mm),
phalanges II-2 (12 mm), manual ungual II (3.5 mm), metacarpals III (23
mm), phalanges III-1 (4 mm), phalanx III-2, ilia (one partial), pubes
(~28 mm), ischia (~17 mm), femora (36 mm), tibiae (42 mm), fibulae (one
incomplete; ~21 mm), astragali, calcaneum, distal tarsus, metatarsal
II, phalanges II-1 (6 mm), phalanges II-2 (one fragmentary; 5 mm),
pedal unguals II (5 mm), metatarsals III (one partial; 22 mm),
phalanges III-1 (6.5 mm), phalanges III-2 (5 mm), phalanges III-3 (4
mm), pedal unguals III (5 mm), metatarsals IV (one partial), phalanges
IV-1 (5 mm), phalanges IV-2 (one partial; 3 mm), phalanx IV-3 (2.5 mm),
phalanges IV-4 (one partial; 2 mm), pedal unguals IV (4 mm),
gastroliths (Zhou et al., 2013)
(IVPP V17091) (subadult) skull, sclerotic plates, mandibles, hyoids, eight cervical
vertebrae, cervical ribs, three dorsal vertebrae, dorsal ribs, gastralia, synsacrum,
six caudal vertebrae, pygostyle, scapulae (~43 mm), coracoids (19 mm), furcula,
sternum, sternal ribs, humeri (one incomplete; 49 mm)), radii (one partial;
52 mm) ulnae (one partial; 54 mm), scapholunare, pisiform, (carpometacarpus 25 mm)
semilunate carpal, metacarpal I (5 mm), phalanges I-1 (one fragmentary; 9 mm),
manual unguals I (4 mm), metacarpals II (one fragmentary; 23 mm), phalanx II-1
(11 mm), phalanx II-2 (10 mm), manual ungual II (2.5 mm), metacarpals III (one
partial; 21 mm), phalanx III-1 (5 mm), phalanx III-2, ilia, pubes (~30 mm),
ischia (~14 mm), femora (34 mm), tibiae (one incomplete; 39 mm), fibulae (one
partial; 28 mm), astragali, calcanea, distal tarsi, metatarsals II, phalanges
II-1 (5.5 mm), phalanges II-2 (4 mm), pedal unguals II (4 mm), metatarsals III
(19 mm), phalanges III-1 (6 mm), phalanges III-2 (5 mm), phalanges III-3 (4
mm), pedal unguals III (4 mm), metatarsals IV, phalanges IV-1 (4.5 mm), phalanges
IV-2 (3.5 mm), phalanx IV-3 (2 mm), phalanx IV-4 (2 mm), pedal ungual IV (3.5
mm), body feathers, remiges, gastroliths (Zhou et al., 2013)
Early Albian, Early Cretaceous
Toudaoyingzi, Jiufotang Formation, Liaoning, China
(STM 7-11) (subadult) fragmentary skull, dentaries, several cervical
vertebrae, fragmentary dorsal vertebrae, dorsal ribs, uncinate
processes, caudal vertebrae, pygostyle, scapulae, coracoids,
humeri, radii, ulnae, pisiform, semilunate carpal, metacarpals I,
phalanges I-1, manual unguals I, metacarpals II, phalanx II-1, phalanx
II-2, metacarpals III, phalanx III-1, pubes, femora, tibiae, fibulae,
astragali, calcaneum, metatarsals I, phalanges I-1, pedal unguals I,
metatarsals II, phalanges II-1, phalanges II-2, pedal unguals II,
metatarsals III, phalanges III-1, phalanges III-2, phalanges III-3,
pedal ungual III, metatarsals IV, phalanges IV-1, phalanges IV-2,
phalanges IV-3, phalanges IV-4, pedal ungual IV, lungs, body feathers,
remiges, retrices, ~100 gastroliths (Wang, O'Connor, Maina, Pan, Wang,
Wang, Zheng and Zhou, 2018)
Diagnosis- (after Zhou and Zhang, 2006) premaxilla toothless (also in
Ichthyornis+Passer); maxilla toothless (also in Aves); dentary
toothless (also in Longicrusavis and Carinatae); premaxillae broad with
slightly rounded tips; dentary spatulate; strong longitudinal medial ridge on
dentary dorsal to Meckelian groove; pointed omal tips of furcula (also in Yixianornis);
forelimb elongate (humerus+ulna / femur+tibiotarsus ratio of 138%) (also large
in Ichthyornis- ~176%); tibiotarsofemoral ratio 1.14.
(after Wang and Zhou, 2017) glenoid facet of coracoid strongly projects laterally;
lateral margin of coracoid longer than medial margin; posterior surface of furcula
excavated by deep furrow.
Other diagnoses- Zhou and Zhang (2006) also included the elongate foramina
and grooves on the lateral dentary as a diagnostic character, but this is correlated
with the lack of teeth. The broad sternum with deep posterior notches and elongate
posterolateral processes are symplesiomorphies shared with enantiornithines.
The character "hindlimb shortened" is already covered in forelimb/hindlimb
ratio and tibiotarsal length. Metatarsals II and IV of Patagopteryx,
songlingornithids and Apsaravis are also nearly equal in length.
Comments- This taxon first appeared as a nomen nudum OTU in Zhou and
Zhang's (2005) online matrix, though it did not appear in their cladogram. If
the matrix is run in PAUP, Archaeorhynchus forms an unresolved polytomy
with Hongshanornis, Liaoningornis and more derived euornithines
(Apsaravis, songlingornithids and Ornithurae). This is
the same as the published tree in Zhou and Zhang (2006). In both papers, Patagopteryx
was coded but excluded for no stated reason, yet emerges as the most basal euornithine
when the matrix is run with it.
References- Zhou and Zhang, 2005. Discovery of an ornithurine bird and
its implication for Early Cretaceous avian radiation. Proceedings of the National
Academy of Sciences. 102(52), 18998-19002.
Zhou and Zhang, 2006. A beaked basal ornithurine bird (Aves, Ornithurae) from
the Lower Cretaceous of China. Zoologica Scripta. 35, 363-373.
Zhou, Zhou and O'Connor, 2013. Anatomy of the basal ornithuromorph bird Archaeorhynchus
spathula from the Early Cretaceous of Liaoning, China. Journal of Vertebrate
Paleontology. 33(1), 141-152.
Wang and Zhou, 2017 (online 2016). A new adult specimen of the basalmost ornithuromorph bird
Archaeorhynchus spathula (Aves: Ornithuromorpha) and its implications
for early avian ontogeny. Journal of Systematic Palaeontology. 15(1), 1-18.
Wang, O'Connor, Pan and Zhou, 2017. A bizarre Early Cretaceous
enantiornithine bird with unique crural feathers and an ornithuromorph
plough-shaped pygostyle. Nature Communications. 8:14141.
Wang, O'Connor, Maina, Pan, Wang, Wang, Zheng and Zhou, 2018. Archaeorhynchus preserving significant soft tissue including probable fossilized lungs.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021a online
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
= O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021a online
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Material-
(IVPP V26198) incomplete premaxillae, ?maxilla, frontals, braincase,
?palatines (20.6 mm), ?pterygoid, mandibles (45.9 mm), ?third cervical
vertebra (4.86 mm), ?fourth cervical vertebra, ?fifth cervical vertebra
(7.01 mm), ?sixth cervical vertebra (5.16 mm), ?seventh cervical
vertebra (6.4 mm), ?eighth cervical vertebra, ?ninth cervical vertebra,
posterior cervical vertebra, two dorsal vertebrae (3.73 mm), dorsal rib
fragments
Diagnosis- (after O'Connor et
al., 2022) premaxillae fused anteriorly; toothless dentary that
is dorsoventrally shallow, gently curved, and that gradually tapers
anteriorly; quadrate cotyles of mandible anteroposteriorly narrow.
Differs from Archaeorhynchus in- anteroventral expansion of dentary absent; dentary more elongate.
Differs from Eogranivora in- dentary symphysis unfused.
Differs from Xinghaiornis in- dorsal surface of the dentary is gently concave instead of striaght.
Comments- Discovered in 2004 or 2005, this was first mentioned by Harris et al. (2009) as likely referrable to Gansus,
it being one of three specimens which "consist primarily of the caudal
halves of crania", in left lateral view that "also preserves portions
of dentaries that, although toothless, may possess very small
alveoli." O'Connor et al. (2021) presented it at a later SVP
presentation as a new taxon "Meemannavis ductrix", mentioned in the
abstract as that specimen with the edentulous dentary. It was
named and described by O'Connor et al. (2021 online), but the paper
had
no mention of ZooBank and
"Meemannavis" lacked an entry on the ZooBank
website. Thus according to ICZN Article 8.5.3 (an electronic work
must "be registered in the Official Register of Zoological Nomenclature
(ZooBank) (see Article 78.2.4) and contain evidence in the work itself
that such registration has occurred"), "Meemannavis ductrix" O'Connor
et al.,
2021 was a nomen nudum that became valid in September 2022 once the
volume was published. O'Connor et al. (2022) suggest
that one of the possible palatines may be a prearticular, and that part
of the possible pterygid may be a quadrate.
O'Connor et al. (2021, 2022) added it to O'Connor's bird matrix
and recovered it in a large polytomy of euornithines, excluded from
Neognathae, Schizhoouridae and several pairs of OTUs. Note the
trees in their figure are majority rule and implied weighting.
Adding it to Hartman et al.'s maniraptoromorph analysis results in a
sister group relationship with Archaeorhynchus.
References-
Harris, Lamanna, Li and You, 2009. Avian cranial material and cranial cervical
vertebrae from the Lower Cretaceous Xiagou Formation of Gansu Province, China.
Journal of Vertebrate Paleontology. 29(3), 111A.
O'Connor, Lamanna, Harris, Hu, Bailleul, Wang and You, 2021. First
avian skulls from the Lower Cretaceous Xiagou Formation, Gansu, China.
The Society of
Vertebrate Paleontology Virtual Meeting Conference Program, 81st Annual
Meeting. 196.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
(online 2021). Avian skulls represent a diverse ornithuromorph fauna
from the
Lower Cretaceous Xiagou Formation, Gansu Province, China. Journal of
Systematics and Evolution. 60(5), 1172-1198.
Piscivoravis Zhou, Zhou and O'Connor,
2013 online
P. lii Zhou, Zhou and O'Connor, 2013 online
Early Albian, Early Cretaceous
Xiaotaizi, Jiufotang Formation, Liaoning, China
Holotype- (IVPP V17078) (subadult) posterior skull, posterior mandible,
partial hyoids, ten cervical vertebrae, twelve dorsal vertebrae, thirteen dorsal
ribs (some partial), uncinate processes, several gastralia, synsacrum, three
caudal vertebrae, pygostyle (14.58 mm), scapula (61 mm), coracoid (35 mm), incomplete furcula,
sternum, humerus (74 mm), radius (75 mm), ulna (77 mm), scapholunare, pisiform, carpometacarpus
(mcI 7, mcII 34, mcIII 34 mm), phalanx I-1 (17 mm), manual ungual I (10 mm),
phalanx II-1 (15 mm), phalanx II-2 (15 mm), manual ungual II (6 mm), phalanx
III-1 (9 mm), ilia, pubes (~63 mm), ischia, femora (56 mm), tibiotarsi (71 mm),
fibulae (one incomplete; 33 mm), metatarsals I (6 mm), phalanges I-1 98 mm),
pedal unguals I (5 mm), tarsometatarsi (35.6 mm), phalanges II-1 (12 mm), phalanges
II-2 (11 mm), pedal unguals II (7 mm), phalanges III-1 (13 mm), phalanges III-2
(one partial; 10 mm), phalanx III-3 (10 mm), pedal ungual III (7 mm), phalanges
IV-1 (10 mm), phalanges IV-2 (8 mm), phalanges IV-3 (6 mm), phalanx IV-4 (7
mm), pedal ungual IV (6 mm), body feathers, remiges, retrices, fish bones
Diagnosis- (after Zhou et al., 2014) anterior 1/3-1/2 of pubis dorsomedially
excavated by deep groove; synsacrum with tall spinous crest that diminishes
posteriorly; furcula with strongly tapered omal tips; sternum broad, width greater
than length; scapula long, tapered and distally constricted; deltopectoral crest
anteriorly deflected; large and strongly curved manual unguals; (humerus+ulna+mcII)/(femur+tibiotarsus+mtIII)
~ 1.14; two well-developed cnemial crests on tibiotarsus.
Comments- Zhou et al.'s article describing the taxon was published online
in 2013 with a ZooBank registration, though the physical version was not published
until 2014. A better photo of the skull and cervicals is present in Wang et al. (2016).
Zhou et al. (2014) added Piscivoravis to a version of Clarke's analysis
and found it to be a basal ornithoromorph in a polytomy with Patagopteryx,
Jianchangornis and more derived taxa.
References- Zhou, Zhou and O'Connor, 2014 (online 2013). A new piscivorous ornithuromorph
from the Jehol Biota. Historical Biology. 26(5), 608-618.
Wang, Zhou and Sullivan, 2016. A fish-eating enantiornithine bird from
the Early Cretaceous of China provides evidence of modern avian
digestive features. Current Biology. 26, 1170-1176.
Ornithuromorpha Chiappe et al., 1999
Definition- (Patagopteryx deferrariisi + Passer domesticus)
(modified from Chiappe, 2002)
Other definitions- (Vorona berivotrensis + Patagopteryx deferrariisi
+ Passer domesticus) (modified from Chiappe, 2001)
(Passer domesticus <- Enantiornis leali) (modified from O'Connor,
Wang and Hu, 2016)
Diagnosis- (proposed) peg and socket quadrate-quadratojugal articulation;
quadrate pneumatic (absent in Hesperornithes); eleven or less dorsal vertebrae
(unknown in Archaeorhynchus and Chaoyangia); nine or more sacral
vertebrae; less than twelve caudal vertebrae (unknown in Archaeorhynchus
and Chaoyangia); pygostyle less than four vertebrae in length; scapula
longer than humerus (absent in Jianchangornis, Yanornis, Gansus
and Hesperornis regalis); carpometacarpus fused distally; metacarpal
I distal articulation shelf-like; pelvis completely fused; posterior trochanter
absent on femur (unknown in Archaeorhynchus and Chaoyangia); distal
vascular foramen enclosed by fusion of metatarsals III and IV (absent in basal
Hesperornithes); hypotarsus present (unknown in Archaeorhynchus and Chaoyangia);
at least one proximal vascular foramen in tarsometatarsus; metatarsal II ginglymoid
(absent in Yanornis, some hesperornithines and Apsaravis).
References- Clarke, 2009. The Mesozoic record of ornithurine birds and
the origin of Aves. Journal of Vertebrate Paleontology. 29(3), 79A.
O'Connor, Wang and Hu, 2016. A new ornithuromorph (Aves) with an elongate rostrum
from the Jehol Biota, and the early evolution of rostralization in birds. Journal
of Systematic Palaeontology. 14(11), 939-948.
Patagopterygiformes Alvarenga and Bonaparte,
1992
Definition- (Patagopteryx deferrariisi <- Passer domesticus)
(Martyniuk, 2012)
= Patagopterygidae Alvarenga and Bonaparte, 1992
= Chaoyangiformes Hou, 1997
Definition- (Chaoyangia beishanensis <- Passer domesticus)
(Martyniuk, 2012)
= "Chaoyangidae" Hou, 1997
= Chaoyangithiformes Zhou and Zhang, 2006
= "Chaoyangornithidae" Zhou and Zhang, 2006
Diagnosis-
Comments- Hou (1997) erected Chaoyangiformes for his new families Chaoyangidae
and Songlingornithidae within basal Euornithes (his Ornithurae). As noted
below in the Songlingornis section of the comments, there are no synapomorphies
that suggest grouping Songlingornis with Chaoyangia. Zhou and
Zhang (2006) later erected the taxa Chaoyangithiformes (credited to Hou, 1997)
and Chaoyangornithidae (this time containing both Chaoyangia and Songlingornis).
Both of these are malformed, as there is no "Chaoyangithes" or "Chaoyangornis".
Moreover, both "Chaoyangidae" and "Chaoyangornithidae" are
nomina nuda, as they were neither diagnosed nor defined (ICZN Article 13.1.1).
References- Alvarenga and Bonaparte, 1992. A new flightless landbird
from the Cretaceous of Patagonia. Los Angeles County Museum of Natural History,
Science Series. 36, 51-64.
Hou, 1997. Mesozoic birds of China. Taiwan Provincial Feng
Huang Ku Bird Park. Taiwan: Nan Tou, 228 pp.
Zhou and Zhang, 2006. Mesozoic birds of China- A synoptic review. Vertebrata
PalAsiatica. 44(1), 60-98.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
unnamed possible patagopterygiforms (Forster and O'Connor, 2000; described by O'Connor
and Forster, 2010)
Middle Maastrichtian, Late Cretaceous
Anembalemba Member of Maevarano Formation, Madagascar
Material- (FMNH PA 779) incomplete coracoid (50.1 mm)
(UA 9602) incomplete coracoid
Comments- The coracoids differ from each other, so are from different
taxa. UA 9602 was found close to the Vorona holotype and is of similar
size, so may belong to that individual. Both specimens seem closer to Aves than
enantiornithines based on the concave scapular articulation, but are primitive
in lacking procoracoid processes as in Patagopteryx
and apsaraviforms. Adding them to Hartman et al.'s maniraptoromorph
analysis results in them being patagopterygiform, with two steps needed
to make them apsaraviform.
References- Forster and O'Connor, 2000. The avifauna of the Upper Cretaceous
Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 20(3),
41A-42A.
O'Connor and Forster, 2010. A Late Cretaceous (Maastrichtian) avifauna from
the Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 30(4),
1178-1201.
Chaoyangia Hou and Zhang,
1993
C. beishanensis Hou and Zhang, 1993
Early Albian, Early Cretaceous
Boluochi, Jiufotang Formation, Liaoning, China
Holotype- (IVPP V9934) (~235 mm) eleven dorsal vertebrae, eight dorsal ribs,
dorsal rib fragments, three uncinate processes, gastralia(?), synsacrum, about
five caudal vertebrae, ilia (one partial; 32 mm), pubes (51 mm), ischia (30
mm), femora (one incomplete; 45 mm), tibiotarsus, proximal fibula, tarsometatarsal
fragment
Diagnosis- (after O'Connor and Zhou, 2013) uncinate
processes expanded basally, forming a 55 degree angle with the rib;
ischium with two, gradually expanding, dorsal processes; ischia
distally contacting; femoral neck poorly defined.
Other diagnoses- Of the characters listed in the diagnosis by Hou and
Zhang (1993), most are symplesiomorphies (non-heterocoelous dorsal vertebrae;
uncinate processes; sacrum not fused to ilia; unfused pelvis; pelvis opisthopubic; preacetabular process
longer than postacetabular process; pubic symphysis; femoral head well developed;
fourth trochanter absent). The longitudinally grooved dorsal ribs are also present
in Archaeorhynchus, Yanornis and Yixianornis, so are more
widely distributed. More than eight sacral vertebrae are present in most euornithines. The ilium is described as "nephroid"
and the femoral shaft "well developed", which are too vague to elaborate.
The postacetabular process was described as expanded, but Hou and Zhang included
portions of the sacrum in the postacetabular process (O'Connor and Zhou, 2013). The
postacetabular process is actually tapered as in most maniraptorans. The pubis
is reported to be pneumatized, which is otherwise only reported in Archaeopteryx
among Mesozoic theropods, but difficult to determine in most specimens and of
uncertain validity in Chaoyangia (perhaps the pubic shaft is hollow but
non-pneumatic). The cnemial crest is equally well developed in Yixianornis
and Yanornis.
Hou (1997) adds a few supposedly diagnostic characters. The thin-walled long
bones (femur and presumably tibia) and fibula unfused to the tibia are symplesiomorphic
for theropods. The femur is said to be pneumatized via a foramen on the proximolateral
side, but this is only reported for Shixinggia among Mesozoic theropods.
Hou's record of erroneous morphological interpretation makes me wary of accepting
this character as valid.
Zhou and Hou (2002) add the character "uncinate processes long, slender
and ventrally distributed to their diagnosis, but they are longer and more slender
in Confuciusornis and similarly placed as well. They also state the postacetabular
process is slightly rounded, but the posterior curvature is similar to Archaeorhynchus,
though taller. A pubic symphysis of about a third of pubic length (30%) falls
within the range of variation in Confuciusornis, and is not that different
from Hongshanornis (26%) or Yanornis (35%). The trochanteric crest
is equally high in taxa like Confuciusornis and Vorona. The rest
of their new diagnostic characters are based on Songlingornis.
Comments- The holotype was discovered in 1990 and was merely
referred to Aves order indet. by Hou and Zhang (1993). Other specimens
were subsequently referred by Hou et al. (1996), but "a partial foot"
was later found to be from an indeterminate euornithine (IVPP V9937),
while "a shoulder girdle including the furcula, coracoids, and sternum"
was made the holotype of a new genus (IVPP V10913- Songlingornis). Hou (1997) states there
are three cervicals and seven dorsals preserved, but such a low number of dorsals
would be unheard of in a non-avian theropod, and it is more likely all ten presacral
vertebrae are dorsals as agreed by O'Connor and Zhou (2013).
Chaoyangia a basal euornithine? Hou et al. (1996) referred
Chaoyangia to basal Euornithes (their Ornithurae) due to
the uncinate processes (now known to be present in many maniraptorans) and several
characters preserved only in IVPP V10913.
Hou (1997) followed Hou et al.'s phylogenetic scheme, with additional evidence
for Chaoyangia being a euornithine being ossified, pneumatized and elongated
gastralia and a well developed cnemial crest. The gastralial characters are
confusing, since no other euornithines known at the time preserved gastralia
besides perhaps a couple elements in the probably incorrectly referred Liaoningornis.
In any case, gastralia are symplesiomorphic for theropods, and are more elongate
in basal taxa like Changchengornis (39% of femoral length) than in euornithines
like Yixianornis (18%). Chaoyangia's are intermediate (28%). The
only theropod with verified pneumatic gastralia is Aerosteon, and I am
doubtful it can be verified in Chaoyangia, especially given Hou's history
of misinterpretation and his additional claims of pneumaticity in the taxon
(femur, pubis, etc.). The cnemial crest is as anteriorly elevated and pointed
in some enantiornithines like Eoenantiornis and has yet to be analyzed
on a broad scale in bird phylogeny.
Zhou (1999) found Chaoyangia to be a basal euornithine (his
Ornithurae) in his thesis. Additional characters not based on Songlingornis
include- proximodorsal ischial process absent; ischium expanded distally due
to low mid dorsal process (not present in Apsaravis, but seems valid);
tall trochanteric crest (miscoded as absent in Confuciusornis and enantiornithines).
Zhang and Zhou (2000) included Chaoyangia in a version of Chiappe's bird
matrix, finding it to be a basal euornithine. In addition to the
uncinate processes and characters based on Songlingornis, this was also
due to the supposedly subparallel pelvic elements (miscoded as present in Chaoyangia),
compressed pubic shaft (miscoded as present in Chaoyangia- Clarke, 2002),
trochanteric crest (miscoded as absent in Confuciusornis, Protopteryx
and Sinornis), and medial cnemial crest (somewhat questionable, as
it may be taphonomic- O'Connor and Zhou, 2013).
Thus despite several miscodings and problematic characters, two characters support
placing Chaoyangia in Euornithes-
proximodorsal ischial process absent; ischium expanded distally due to low mid
dorsal process. Using Hartman et al.'s maniraptoromorph dataset, Chaoyangia falls out sister to Patagopteryx
Chaoyangia a basal pygostylian? Clarke (2002) is one of the few
Western authors to comment on Chaoyangia. She found it to fall out as
a pygostylian outside Ornithuromorpha. This was based on four characters, of which two were misinterpreted in Chaoyangia.
Clarke suggested it had seven sacrals, but O'Connor and Zhou (2013)
more recently show it has at least nine, and possibly up to eleven,
sacrals. Clarke also claimed its pelvic elements were
incompletely fused, but all three elements were fused together in the
holotype. Additionally newly discovered taxa have shown most
basal euornithines are equally primitive in the remaining characters-
all euornithines except Patagopteryx and Apsaravis plus ornithurines have pubic symphyses; and Archaeorhynchus, Schizooura, Yanornis, hongshanornithids, Iteravis
and Gansus have pubic boots. Clarke further claimed that Chaoyangia
was identical to Confuciusornis in all scored characters, and may be
synonymous, but Confuciusornis differs in lacking a pubic boot, having
a narrower postacetabular process, and a shorter ischium with a proximodorsal
process and no mid dorsal process. Forcing Chaoyangia
to be outside Ornithothoraces in the Hartman et al. maniraptoromorph
dataset results in trees 7 steps longer where it falls out by Balaur.
Songlingornis- Hou et al. (1996) referred at least one additional
specimen to Chaoyangia (IVPP V10913), which was later made the holotype
of the new genus Songlingornis (Hou, 1997). The reference of IVPP V10913
to Chaoyangia was followed by Hou and Zhou (1999) and Zhou and Hou (2002),
though the latter did indicate it had also been used as the holotype of Songlingornis.
The specimens preserve few elements in common (though not none, as claimed by
Clarke and Norell, 2001)- several dorsal vertebrae, dorsal ribs and proximal
femur. The dorsals are alike in being non-heterocoelous, but this is similar
to all non-hesperornithine, non-avian birds. Both femora are described as having
proximally projecting trochanteric crests, shallow trochanteric fossae and large
heads. These features are comparable to many basal birds including Confuciusornis
and Vorona. The only point of difference in their descriptions in that
Chaoyangia is said to have a "basically absent" neck, while
Songlingornis has a "relatively well developed neck." Yet Chaoyangia's
proximal femur has a near identical shape to Songlingornis'.
Thus the taxa cannot be distinguished, but also share no synapomorphies
that would allow them to be synonymized. Forcing them to be
sister taxa in the Hartman et al. dataset results in trees only one
step longer, where Songlingornis moves to Patagopterygiformes
References- Hou and Zhang, 1993. A new fossil bird from Lower Cretaceous
of Liaoning. Vertebrata PalAsiatica. 31, 217-224.
Hou, Martin, Zhou and Feduccia, 1996. Early adaptive radiation of birds: evidence
from fossils from northeastern China. Science. 274, 1164-1167.
Hou, 1997. Mesozoic birds of China. Taiwan Provincial Feng Huang Ku Bird Park.
Taiwan: Nan Tou, 228 pp.
Hou and Zhou, 1999. Paleornithology of China: A general review. Chinese Science
Bulletin. 44(23), 2113-2116.
Zhou, 1999. Early evolution of birds and avian flight-evidence from Mesozoic
fossils and modern birds. PhD Dissertation, Department of Systematics and Ecology,
University of Kansas. 216 pp.
Zhang and Zhou, 2000. A primitive enantiornithine bird and the origin of feathers.
Science. 290, 1955-1959.
Clarke and Norell, 2001. Fossils and avian evolution. Nature. 414, 508.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Zhou and Hou, 2002. The discovery and study of Mesozoic birds in China. In Chiappe
and Witmer (eds.). Mesozoic Birds - Above the Heads of Dinosaurs. University
of California Press. 160-183.
Zhou and Zhang, 2006. Mesozoic birds of China- A synoptic review. Vertebrata
PalAsiatica. 44(1), 60-98.
O'Connor and Zhou (online 2012), 2013. A redescription of Chaoyangia beishanensis (Aves)
and a comprehensive phylogeny of Mesozoic birds. Journal of Systematic Palaeontology.
11(7), 889-906.
Patagopteryx Alvarenga
and Bonaparte, 1992
P. deferrariisi Alvarenga and Bonaparte, 1992
Santonian, Late Cretaceous
Bajo de la Carpa Formation of the Rio Colorado Subgroup, Neuquen, Argentina
Holotype- (MACN-N-03) (~545 mm) ninth cervical vertebra (~20 mm), tenth
cervical vertebra (20.0 mm), eleventh cervical vertebra (19.9 mm), twelfth cervical
vertebra (~20 mm), thirteenth cervical vertebra (16.0 mm), first dorsal vertebra
(14.4 mm), second dorsal vertebra (13.0 mm), third dorsal vertebra (12.4 mm),
fourth dorsal vertebra (10.8 mm), fifth dorsal vertebra (14.5 mm), sixth dorsal
vertebra (~12 mm), seventh dorsal vertebra (~12 mm), eighth dorsal vertebra
(12.6 mm), ninth dorsal vertebra (13.2 mm), tenth dorsal vertebra (~13 mm), eleventh
dorsal vertebra (~12 mm), synsacrum (52.6 mm), two caudal vertebrae (9.0, 8.6 mm),
proximal scapulae, proximal coracoids, humeri (one incomplete; 66.3 mm), proximal
radius, proximal ulna, ilia (one incomplete; 68.4 mm), femora (one partial;
~99 mm), incomplete tibiotarsus (~138 mm), partial tarsometatarsus, phalanx
II-1, phalanx III-1, phalanx IV-1, phalanx IV-2, phalanx IV-3
Paratypes- (MACN-N-10) (at least three individuals) metatarsal I, proximal tarsometatarsus,
four distal tarsometatarsi, phalanx II-1 (~16 mm), phalanx III-1 (~20 mm), phalanx IV-1 (~9 mm), phalanx IV-2 (7.0 mm)
(MACN-N-11) posterior skull, posterior mandibles, proatlas, atlas,
axis, third cervical vertebra, fourth cervical vertebra, fifth cervical
vertebra, sixth cervical vertebra, seventh cervical vertebra, eighth
cervical vertebra, four dorsal vertebrae, two dorsal ribs, five caudal
vertebrae, scapula (~73 mm), incomplete coracoids (38.0, 38.0 mm),
partial sternum, incomplete humeri (~59, 59.8 mm), radius (46.0 mm),
incomplete ulnae (~52 mm), carpometacarpus (~23 mm), partial phalanx
II-1 (8.4 mm), phalanx II-2 (11.6 mm), manual ungual II (~7 mm),
partial ilia, pubes (one incomplete; ~50 mm), incomplete ischia (50.4,
52.5 mm), femur (~100 mm), tibiotarsus (~137, ~136 mm), partial fibula,
metatarsals I (14.8 mm), phalanges I-1 (11.9, 11.9 mm), pedal unguals I
(~18 mm), tarsometatarsi (~49, 50.8 mm), phalanges II-1 (~16, 15.8 mm),
phalanges II-2 (12.6 mm), pedal ungual II (18.0 mm), phalanges III-1
(20.3, 20.3 mm), phalanx III-2 (14.4 mm), phalanx III-3 (11.6 mm),
pedal ungual III (~17 mm), phalanx IV-1 (~10 mm), phalanx IV-2 (7.3
mm), phalanx IV-3 (6.0 mm), phalanx IV-4 (7.5 mm), pedal ungual IV (~16
mm)
Referred- (MACN-N-14) six cervical vertebral fragments,
?first dorsal vertebral fragment, second dorsal vertebra (11.6 mm),
third dorsal vertebra (9.1 mm), fourth dorsal vertebra (12.8 mm), fifth
dorsal vertebra (~12 mm) (Chiappe, 1992)
(MUCPv-48) skull fragments including braincase, two posterior dorsal
vertebrae, mid caudal vertebra (10.3 mm), partial ilium, incomplete
femur (~98 mm), tibiotarsi (~141 mm; one incomplete, one distal),
fibula (~112 mm), metatarsals I, phalanx I-1 (11.8 mm), pedal ungual I,
tarsometatarsi (51 mm; one fragmentary), phalanx II-1 (15.8 mm),
phalanx II-2 (12.8 mm), proximal pedal ungual II, phalanx III-1 (~20
mm), distal phalanx III-2, phalanx III-3 (10.6 mm), pedal ungual III
(~20 mm), phalanx IV-1 (8.8 mm), phalanx IV-2 (6.1 mm), phalanx IV-3
(5.9 mm), phalanx IV-4 (7.4 mm), partial pedal ungual IV (Chiappe, 1991)
(MUCPv-207) several vertebrae, partial synsacrum, mid caudal vertebrae, partial
hindlimb (Chiappe, 2002a)
Diagnosis- (after Alvarenga and Bonaparte, 1992) cervical vertebrae completely
heterocoelous (also in Ornithurae); dorsal vertebrae 6-11 procoelous;
reduced forelimbs; large lateral process on distal postacetabular process; medial
process on distal postacetabular process.
(after Chiappe, 1996a) quadrate fused to pterygoid; quadrate foramen present
laterally; fifth dorsal vertebra biconvex; posterior dorsal vertebrae with very
wide reniform centra; posterior articular surface of synsacrum convex; acromion
transversely expanded anteriorly; proximal end of coracoid with dorsally projecting
section for scapular articulation; two prominent intermuscular lines on dorsal
shaft of humerus; distal ulna extremely anteroposteriorly compressed; metacarpal
III more robust than metacarpal II; strong medial laminar process on metacarpal
II (a reduced metacarpal I?); pubis anteroposteriorly compressed; distal pubis
anteriorly curved; prominent m. iliofibularis tubercle on fibula; distal fibula
fused to anterior side of tibiotarsus; minimum width of tarsometatarsus over
20% of length; untwisted metatarsal I.
(after Chiappe, 2002a) acromion dorsoventrally expanded at tip (also in Apsaravis).
Other diagnoses- Some of Alvarenga and Bonaparte's (1992) diagnostic
characters are symplesiomorphic- notarium absent; anterior articular surface
of synsacrum strongly concave; synsacrum dorsoventrally compressed; synsacrum
transversely wide; humerus lacks pneumotricipital foramen; ilium weakly fused
to synsacrum; preacetabular process vertically oriented; preacetabular process
laterally far from synsacrum; iliac crest single and extends to posterior margin
of ilium; opisthopubic pelvis; ilioischial fenestra open; iliopubic fenestra
open; lateral cnemial crest anteriorly developed; supratendinal bridge absent
on tibiotarsus.
Of Chiappe's (2002a) diagnostic characters, the prominent iliac crest is plesiomorphic
for avepods and the "well developed caudolateral spine" seems to be
the supratrochanteric process common in basal birds. The ischium is also paddle-shaped
in Yixianornis, Gansus, Ichthyornis and Iaceornis.
Comments- The holotype and MACN-N-10 were discovered in 1984, while MACN-N-11
was discovered in 1985. They were first commented on by Bonaparte (1986), who
described them as ratite-like. Chiappe (1991) noted the description of the then
unnamed taxon was in press, also mentioning MUCPv-48 as "housed in the
UNC". The taxon was formally described by Alvarenga and Bonaparte (1992),
and redescribed by Chiappe, first in his unpublished thesis (1992), then in
1996a, and finally in depth in 2002a. Chinsamy et al. (1994, 1995) described
its histology.
Alvarenga and Bonaparte (1992) stated there are indications that the then unprepared
MACN-N-11 lacked a pygostyle, but this cannot be confirmed. The supposed furcular
epicleidia in the holotype were later determined to be proximal coracoids (Chiappe,
1996). The supposed distal coracoid preserved in the holotype is probably not
a Patagopteryx element (Chiappe, 1996). Hutchinson (2001) identified
a proximodorsal ischial process and an obturator flange.
Patagopteryx a palaeognath? Alvarenga and Bonaparte (1992) and
Alvarenga (1993) proposed a close relationship to palaeognaths, rheiforms in
particular, but also lithornithiforms, tinamiforms, casuariiforms and apterygiforms.
Characters supporting this are largely symplesiomorphic for birds- elongate
acromion on scapula; pneumotricipital foramen absent (a reversal in ratites);
open ischiopubic fenestra; open ilioischiadic fenestra; deep and triangular
popliteal fossa; robust and anteriorly developed lateral cnemial crest; supratendinal
bridge absent (probably a reversal in some lithornithids and ratites); round
lateral tibiotarsal condyle; reduced hypotarsus (a reversal in ratites). "General
form and proportions" of cervical vertebrae being similar to tinamiforms
is too vague to evaulate. The supposedly horizontal postacetabular process would
be primitive for carinates, but seems to be untrue in Patagopteryx in
any case. Patagopteryx's trochanteric crest is not wide and planar laterally,
as it has a lateral ridge and ITCR insertion scar. The trochanteric crest does
not appear more anteriorly expanded than enantiornithines or Vorona.
The supposedly medially placed tendinal groove is instead a depression formed
by the extensor retinaculum ridges as in Apsaravis (Clarke and Norell,
2002), so is not homologous to the condition in palaeognaths. The tibiotarsal
intercondylar groove is not particularly shallow or wide, contra Alvarenga and
Bonaparte. Chiappe (1995) noted there is no "tendency for the ischia to
become horizontal and approach each other medially", though the latter
would be primitive for birds. Chiappe also notes Patagopteryx has a single
cnemial crest, not two in which the "inner is formed over the outer"
as is apparently the case in some ratites. The dorsoventrally flattened posterior
dorsal centra and anteroposteriorly compressed ulna are apparently similar to
rheiforms and are otherwise unknown in basal euornithines.
Kurochkin (1995) placed Patagopteryx within Ratitae based on several
characters. The heterocoelous cervical vertebrae are symplesiomorphic for avians,
and are found in some basal euornithines like Apsaravis and hesperornithines
as well. The dorsals are said to be "transitional to heterocoely or procoelous",
but Patagopteryx also has opisthocoelous and biconvex dorsals. Heterocoelous
dorsals are similar to Aves and Hesperornithes, but no palaeognaths seem to
have procoelous dorsals. Contra Kurochkin, the tibiotarsus lacks an anterior
cnemial crest, which would be symplesiomorphic for a more inclusive clade than
Ratitae in any case. The completely fused tarsometatarsus is symplesiomorphic
for euornithines. A hallux with two phalanges is symplesiomorphic for all
reptiles.
There are a few additional Aves characters which Patagopteryx does possess-
a tricondylar quadrate articulation; the deltopectoral crest is oriented anteriorly
(also in Alamitornis); the deltopectoral crest is lower than shaft width
(also in Alamitornis and hesperornithines); pubic symphysis absent (also
in Apsaravis, hesperornithines and Carinatae). While there are several
characters shared with Aves and a couple apparently shared with Rheiformes,
these are outweighed by the large number of characters suggesting a more basal
position, as described below.
Patagopteryx a hesperornithine? Chatterjee (1999) performed a
phylogenetic analysis which found Patagopteryx to be the sister taxon
of Hesperornithiformes. This was only based on the ulna being shorter than the
humerus (miscoded in Ichthyornis and now also known to be true in Hongshanornis
and Apsaravis) and the supposedly absent distal trochlear surface on
the ulna (actually unknown in Patagopteryx). In addition, Patagopteryx
has to reverse the spherical head found in ornithurines in Chatterjee's
cladogram. Thus there is basically no support for placing Patagopteryx
in Hesperornithes.
Patagopteryx an enantiornithine? Feduccia (1999) listed Patagopteryx
under Enantiornithes, though he did not mention reasons besides noting both
Patagopteryx and Lecho Formation enantiornithines have LAGS in their
femoral histology. However, these are also present in Rahonavis, so are
probably plesiomorphic. While Patagopteryx does share a few characters
with enantiornithines (e.g. some of the latter have tarsometatarsi which are
excavated posteriorly), it has many more euornithine characters.
Patagopteryx a basal euornithine? Chiappe (1991) first suggested the then unnamed Patagopteryx
was unrelated to any ornithurine. His 1992 thesis proposed it
was basal to Ornithurae, though this was not published until
Chiappe and Calvo (1994) (elaborated on in Chiappe, 1995). That phylogenetic
analysis supported excluding Patagopteryx from Ornithurae
as the basalmost euornithine based on- pterygoid process of quadrate rounded;
more than ten dorsal vertebrae (now also known to be more primitive than songlingornithids,
Apsaravis and Gansus); uncinate processes absent (probably untrue,
as only a few ribs are preserved and uncinates are primitive for maniraptorans);
procoracoid process absent (now also known to be more primitive than Archaeorhynchus,
Hongshanornis, Ambiortus, songlingornithids and Gansus);
humeral head anteriorly concave (now also known to also be more primitive than
Hongshanornis, Ambiortus, songlingornithids, Apsaravis
and Gansus); acetabulum >11% of ilial length (now also known to be
more primitive than songlingornithids and Gansus); pubis and ischium
not parallel to ilium (now also known to be more primitive than Apsaravis
and Gansus); pubis not laterally compressed (now known also to be more
primitive than Apsaravis); femur lacks patellar groove (now also known
to be more primitive than Apsaravis and Gansus); anterior cnemial
crest absent (now also known to be more primitive than Archaeorhynchus
and Gansus); m. iliofibularis tubercle of fibula not posteriorly oriented
(now also known to be more primitive than Gansus); metatarsal III not
plantarily displaced proximally (now also known to be more primitive than songlingornithids,
Apsaravis and Gansus); intercotylar eminence of tarsometatarsus
poorly developed. In 1996a, Chiappe performed another analysis which added an
additional character to support this- articular not pneumatic (now also known
to be more primitive than Archaeorhynchus). In 2001 (repeated in 2002b),
Chiappe expanded the analysis once more, finding Patagopteryx and Vorona
to be basal to ornithurines. Added characters which supported
excluding Patagopteryx from the latter clade are- anterior articular
surface of synsacrum strongly concave (somewhat ambiguous, as it is somewhat
concave in most coelurosaurs); extensor canal absent on tibiotarsus (now also
known to be more primitive than Archaeorhynchus, songlingornithids and
Apsaravis); wide medial condyle on tibiotarsus (now also known to be
more primitive than Apsaravis and Gansus); transverse groove proximally
undercuts tibiotarsal condyles (now also known to be more primitive than Gansus
and probably Archaeorhynchus).
Norell and Clarke (2001) first published Clarke's matrix, which found Patagopteryx
was not only basal to ornithurines, but also their new taxon Apsaravis.
Additional basal euornithines have subsequently been added to the matrix
(Hongshanornis, Archaeorhynchus, Ambiortus, songlingornithids,
Gansus), which have all ended up more derived than Patagopteryx
as well. New characters which support placing Patagopteryx outside Ornithurae
are- less than ten sacral vertebrae (also more primitive than
Apsaravis and Gansus); humerus not domed proximally (also more
primitive than Archaeorhynchus, Hongshanornis, Ambiortus,
songlingornithids, Apsaravis and Gansus); radius without muscle
impression along ventroposterior surface (also more primitive than Archaeorhynchus
and Apsaravis); metacarpal III >50% of width of metacarpal II (also
more primitive than Yanornis, Yixianornis and Apsaravis);
manual phalanx II-1 not strongly compressed dorsoventrally (also more primitive
than Archaeorhynchus, Hongshanornis, Ambiortus, songlingornithids,
Apsaravis and Gansus); antitrochanter directly posterior to acetabulum
(probably a reversal, as more basal avialans have the opposite
state); only one proximal vascular foramen on tarsometatarsus; fossa for metatarsal
I on tarsometatarsus absent. In addition, Patagopteryx can be excluded
from Carinatae due to- dorsal vertebrae lack ossified tendons on transverse
processes; sacral vertebrae lack a series with short dorsally oriented transverse
processes (also more primitive than Gansus). Finally, it can be excluded
from Aves based on- quadrate foramen not located posteromedially; less than
fifteen sacral vertebrae; no pneumatic foramen in humerus; the ilium does not
overlap any dorsal ribs (also more primitive than Gansus); distal vascular
foramen with one exit.
Cau and Arduini (2008) found Patagopteryx in a similar position, basal
to all euornithines except Vorona. New characters influencing this
position are- large hypapophyses absent in mid dorsals (also more primitive
than Gansus); mid sacral centra not transversely compressed (also more
primitive than Gansus); coracoid lateral process absent (this is miscoded
in Patagopteryx); sternal keel absent (probably a reversal due to flightlessness,
as Confuciusornis sometimes has a keel); manual phalanx II-2 longer than
II-1 (also more primitive than Ambiortus, songlingornithids and Gansus);
proximodorsal process on ischium (also more primitive than Archaeorhynchus,
Chaoyangia, songlingornithids, Apsaravis and Gansus); fibula
longer than half tibiotarsal length (also more primitive than Hongshanornis,
songlingornithids and Gansus). Additionally, it is excluded from Carinatae
based on- acrocoracoid process not hooked medially; coracoid foramen absent
(miscoded in Aves, as it is absent in most, so not valid for excluding Patagopteryx);
metatarsal II ginglymoid (miscoded in Ichthyornis and polymorphic in
Aves, so not very useful for excluding Patagopteryx).
Gao et al. (2008) also found Patagopteryx to be a euornithine basal
to Aves and Gansus. O'Connor et al. (2009) later used the same matrix
with other euornithines added (Hongshanornis, PKUP V1069, Apsaravis,
Yanornis, Hesperornis, Ichthyornis) and found Patagopteryx
to be basal to all of them. New characters supporting this include- well developed
olecranon fossa absent in humerus (also absent in Apsaravis, Hesperornithes
and Ichthyornis; so probably convergent in Yixianornis and Aves,
but does exclude Patagopteryx from the latter); m. scapulotriceps groove
absent in humerus (also absent in Apsaravis, some Ichthyornis
and palaeognaths; so probably convergent in Yixianornis and Neognathae);
ischium >66% of pubic length (highly homoplasic once taxa that aren't included
by have long ischia like Apsaravis, Hesperornithes and Iaceornis
are taken into account); metatarsal I not twisted. In addition, the ungual on
manual digit II excludes it from Iaceornis+Aves and lack of hypotarsal
grooves excludes it from Aves. Some other characters (e.g. open iliosacral canals)
are listed as avian (their neornithine) synapomorphies but not considered here,
as they are actually neognath characters which only appear as avian characters
since no palaeognaths were included.
Thus there are about 29 valid characters excluding Patagopteryx from
Ornithurae, three additional characters excluding it from Carinatae
and six others exclude it from Aves.
References- Bonaparte, 1986. History of terrestrial Cretaceous vertebrates
of Gondwana. Simposio Bioestratigraf�a del Paleozoico Inferior: IV Congreso
Argentino de Paleontolog�a y Bioestratigraf�a, Mendoza, Argentina.
2, 63-95.
Chiappe, 1989. Flightless birds from the Late Cretaceous of Patagonia. Archosaurian
Articulations. 1(10), 73-77.
Chiappe, 1991. Cretaceous birds of Latin-America. Cretaceous Research. 12, 55-63.
Alvarenga and Bonaparte, 1992. A new flightless landbird from the Cretaceous
of Patagonia. Los Angeles County Museum of Natural History, Science Series.
36, 51-64.
Chiappe, 1992. Osteologia y sistematica de Patagopteryx deferrariisi
Alvarenga y Bonaparte (Aves) del Cretacico de Patagonia. Filogenia e historia
biogeografica de las aves Cretacicas de America del Sur. PhD Thesis. Universidad
de Buenos Aires. 429 pp.
Alvarenga, 1993. A origem das aves seus fosseis. In Andrade (ed.). A Vida das
Aves. 16-26.
Chiappe and Calvo, 1994. Neuquenornis volans, a new Upper Cretaceous
bird (Enantiornithes: Avisauridae) from Patagonia, Argentina. Journal of Vertebrate Paleontology.
14(2), 230-246.
Chinsamy, Chiappe and Dodson, 1994. Growth rings in Mesozoic birds. Nature.
368, 196-197.
Chiappe, 1995. The phylogenetic position of the Cretaceous birds of Argentina:
Enantiornithes and Patagopteryx deferrariisi. Courier Forschungsinstitut-Senckenberg.
181, 55-63.
Chinsamy, Chiappe and Dodson, 1995. Mesozoic avian bone microstructure: Physiological
implications. Paleobiology. 21(4), 561-574.
Kurochkin, 1995. Synopsis of Mesozoic birds and early evolution of class Aves.
Archaeopteryx. 13, 47-66.
Chiappe, 1996a. Late Cretaceous birds of Southern South America: Anatomy and
systematics of Enantiornithes and Patagopteryx deferrariisi. In Arratia
(ed.). Contributions of Southern South America to Vertebrate Paleontology. M�nchner
Geowissenschaftliche Abhandlungen (A). 30, 203-244.
Chiappe, 1996b. Early avian evolution in the southern hemisphere: Fossil record
of birds in the Mesozoic of Gondwana. Memoirs of the Queensland Museum. 39,
533-556.
Chatterjee, 1999. Protoavis and the early evolution of birds. Palaeontographica
A. 254, 1-100.
Feduccia, 1999. The Origin and Evolution of Birds. Yale University Press, New
Haven, CT. 466 pp.
Chiappe, 2001. Phylogenetic relationships among basal birds. In Gauthier and
Gall (eds.). New perspectives on the origin and early evolution of birds: Proceedings
of the international symposium in honor of John H. Ostrom. Peabody
Museum of Natural History. 125-139.
Hutchinson, 2001. The evolution of pelvic osteology and soft tissues on the
line to extant birds (Neornithes). Zoological Journal of the Linnean Society.
131, 123-168.
Norell and Clarke, 2001. Fossil that fills a critical gap in avian evolution.
Nature. 409, 181-184.
Chiappe, 2002a. Osteology of the flightless Patagopteryx deferrariisi
from the Late Cretaceous of Patagonia (Argentina). Mesozoic Birds:
Above the Heads of Dinosaurs. University of California Press. 281-316.
Chiappe, 2002b. Basal bird phylogeny: Problems and solutions. In Chiappe and
Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 448-472.
Clarke and Norell, 2002. The morphology and phylogenetic position of Apsaravis
ukhaana from the Late Cretaceous of Mongolia. American Museum Novitates.
3387, 46 pp.
Cau and Arduini, 2008. Enantiophoenix electrophyla gen. et sp. nov. (Aves,
Enantiornithes) from the Upper Cretaceous (Cenomanian) of Lebanon and its phylogenetic
relationships. Atti della Societa Italiana di Scienze Naturali e del Museo Civico
di Storia Naturale in Milano. 149(2), 293-324.
Gao, Chiappe, Meng, O'Conner, Wang, Cheng and Liu, 2008. A new basal lineage
of Early Cretaceous birds from China and its implications on the evolution of
the avian tail. Palaeontology. 51(4), 775-791.
O'Conner, Wang, Chiappe, Gao, Meng, Cheng and Liu, 2009. Phylogenetic support
for a specialized clade of Cretaceous enantiornithine birds with information
from a new species. Journal of Vertebrate Paleontology. 29(1), 188-204.
Yanornithiformes Zhou and Zhang, 2001
Definition- (Yanornis martini <- Passer domesticus) (Martyniuk,
2012)
= Yanornithidae Zhou and Zhang, 2001
Definition- (Yanornis martini, Abitusavis lii <- Yixianornis grabaui, Piscivoravis lii, Passer domesticus) (Wang, Li, Liu and Zhou, 2020)
Comments- Zhou and Zhang (2001) named Yanornithidae
and Yanornithiformes for Yanornis, while placing Yixianornis in
Chaoyangornithiformes. Clarke et al. (2002) were the first to suggest
placing the these taxa plus Songlingornis into a single clade at their SVP talk, though this was
not published until 2006. You et al. (2006) independently coded Yanornis
and Yixianornis and found the taxa to form a monophyletic clade in some
of their most parsimonious trees, though in others Yanornis was more
derived and sister to Apsaravis. The monophyletic clade of Yanornis,
Yixianornis and/or Songlingornis has been called Songlingornithidae
by many recent authors, but here Yanornis is recovered as further from Aves than Yixianornis and Songlingornis based on Hartman et al.'s maniraptoromorph matrix.
References- Zhou and Zhang, 2001. [Two new genera of ornithurine birds from the Early Cretaceous
of Liaoxi involved in the origin of modern birds.] Kexue Tongbao. 46(5), 371-377.
Clarke, Zhou and Zhang, 2002. An ornithurine from the Early Cretaceous of China.
Journal of Vertebrate Paleontology. 22(3), 45A.
Clarke, Zhou and Zhang, 2006. Insight into the evolution of avian flight from
a new clade of Early Cretaceous ornithurines from China and the morphology of
Yixianornis grabaui. Journal of Anatomy. 208, 287-308.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Wang, Li, Liu and Zhou, 2020. Two new Early Cretaceous ornithuromorph
birds provide insights into the taxonomy and divergence of
Yanornithidae (Aves: Ornithothoraces). Journal of Systematic
Palaeontology. 18(21), 1805-1827.
Yanornithiformes indet. (Zhou and Zhang, 2001)
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Material- (IVPP V10996; paratype of Yanornis martini)
(620 g) anterior skull, incomplete dentary, few cervical vertebrae, several dorsal vertebrae, incomplete
coracoids, furcula, fragmentary sternum?, incomplete humeri (~78.5 mm),
radii, ulnae (~78.5 mm), carpometacarpi (~38.1 mm), phalanx II-1?, femur (~53.7
mm), tibiotarsus (~72.6 mm), tarsometatarsi (one fragmentary), few pedal
phalanges (Zhou and Zhang, 2001)
Barremian-Albian, Early Cretaceous
Jehol Group, Liaoning, China
(STM 9-5) scapula, incomplete humeri, partial radii, partial ulnae, femora,
tibiotarsi, phalanx I-1, tarsometatarsi, phalanges II-1, phalanges II-2, pedal
unguals II, phalanges III-1, phalanges III-2, phalanges III-3, pedal unguals
III, phalanx IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4, pedal ungual
IV, pedal claw sheaths, pedal scales, body feathers, remiges (Zheng et al.,
2013)
(STM 9-18) skull (60 mm), mandibles, cervical series, dorsal vertebrae, dorsal
ribs, gastralia, scapula (~50 mm), coracoids (35 mm), sternal ribs, humeri (73
mm), radii, ulnae (79 mm), carpometacarpus (35 mm), phalanx I-1, phalanx II-1 (~17 mm),
phalanx II-2, pubes, femora (49 mm), tibiotarsi (~70 mm), fibula, metatarsal
I, phalanx I-1, pedal ungual I, tarsometatarsi (~31 mm), phalanges II-1, phalanges
II-2, pedal unguals II, phalanges III-1, phalanges III-2, phalanx III-3, pedal
ungual III, phalanges IV-1, phalanges IV-2, phalanx IV-3, phalanx IV-4, pedal
ungual IV, actinopterygian, actinopterygian fragments (Zheng et al., 2014)
(STM 9-31) skull (60 mm), mandibles, hyoids, cervical series with fused ribs,
dorsal vertebrae, caudal vertebrae, pygostyle, scapula, coracoid, furcula, partial
humerus, femora, tibiotarsi, tarsometatarsi (~52 mm), pedal phalanges, pedal
unguals, cf. Jinanichthys, actinopterygian fragments (Zheng et al., 2014)
(STM 9-51) skull (~64 mm), mandibles, hyoids, cervical series, dorsal series,
dorsal ribs, three uncinate processes, gastralia, synsacrum, caudal series,
pygostyle, scapulae (42 mm), coracoid (~30 mm), sternal fragments, humeri (67
mm), radii, ulnae (~71 mm), scapholunare, pisiform, partial carpometacarpus, partial
phalanx I-1, manual ungual II, manual claw sheath, ilia, pubes, ischia, femora
(57 mm), tibiotarsi (75 mm), fibulae, metatarsal I, phalanges I-1, pedal unguals
I, tarsometatarsi (35 mm), phalanges II-1, phalanges II-2, pedal unguals II,
phalanges III-1, phalanges III-2, phalanges III-3, pedal unguals III, phalanges
IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4, pedal unguals IV, body
feathers, retrices, actinopterygian fragments, 3-5 gastroliths (1.1-1.9 mm)
(Zheng et al., 2014)
Comments- The paratype of Yanornis martini
(IVPP V10996) has yet to be described but was figured by
Wang et al. (2020), who correctly noted "few diagnostic features can be
identified from this specimen" and referred it to Yanornithidae
indet.. Indeed no characters of Yanornis or Similiyanornis can be seen, so it is placed in Yanornithiformes indet. here.
Zheng et al. (2013) briefly described the feathers and pedal scales of STM 9-5 which they referred to Yanornis
based on "carina approaching sternal anterior limit, scapula shorter
than humerus, pubic symphysis relatively long, distal tarsals fused to
metatarsals and metatarsals co-ossified proximally and distally, pedal
digits relatively short and robust, and proximal pedal phalanges
relatively long but unguals short", but these are also present (where
known) in Similiyanornis and no characters distinguishing the taxa can be seen in STM 9-5. It is referred to Yanornithiformes indet. here.
Zheng et al. (2014) figured STM 9-18, which although poorly prepared
appears to have a short manual phalanx II-1 like Yanornis (48% of
carpometacarpal length versus 67%) but an unexpanded procoracoid
process like Similiyanornis. Dentary morphology should be
scorable but is not determinable in the figure. This should help
support potential hypotheses such as Similiyanornis' elongate phalanx
or unexpanded procoracoid process being individual variation, or even
synonymy of the genera.
References-
Zhou and Zhang, 2001. Two new ornithurine birds from the Early Cretaceous of
western Liaoning, China. Chinese Science Bulletin. 46(1), 1-7.
Zheng, Zhou, Wang, Zhang, Zhang, Wang, Wei, Wang and Xu, 2013. Hind wings in
basal birds and the evolution of leg feathers. Science. 339, 1309-1312.
Zheng, O'Connor, Huchzermeyer, Wang, Wang, Zhang and Zhou, 2014. New specimens
of Yanornis indicate a piscivorous diet and modern alimentary canal.
PLoS ONE. 9(4), e95036.
Yanornis Zhou and Zhang, 2001
= "Archaeoraptor" sensu Sloan, 1999 in part
= Archaeovolans Czerkas and Xu, 2002
= Abitusavis Wang, Li, Liu and Zhou, 2020
Y. martini Zhou and Zhang, 2001
= "Archaeoraptor liaoningensis" Sloan, 1999 in part
= Archaeovolans repatriates Czerkas and Xu, 2002
= Yanornis guozhangi Wang, Ji, Teng and
Jin, 2013
= Abitusavis lii Wang, Li, Liu and Zhou, 2020
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Holotype-
(IVPP V12558) (~275 mm, 770 g) skull (72.47 mm), mandibles, hyoid, ten
cervical vertebrae, several dorsal vertebrae (6.3 mm), five dorsal
ribs, gastralia?, synsacrum (37.43 mm), pygostyle (15.02 mm), scapulae
(~55 mm), coracoids (34.21 mm), furcula, sternum (48.4 mm), humeri (85.31
mm), radii (85.97 mm), ulnae (90.32 mm), scapholunare, pisiform,
carpometacarpus (39.24 mm, mcI 8.58 mm),
phalanx I-1 (19.05 mm), manual ungual I (10.31 mm), phalanx II-1 (18.64 mm),
phalanx II-2 (17.42 mm), manual ungual II (7.28 mm), phalanx III-1, ilia,
pubes (~67 mm), ischium, femora (55.77 mm), tibiotarsi (82.42 mm), fibulae
(32 mm), metatarsals I (6.33 mm), phalanges I-1 (8.41 mm), pedal unguals I
(5 mm), tarsometatarsi (37.87 mm), phalanges II-1 (14.27 mm), phalanx II-2
(10.5 mm), pedal ungual II (5.76 mm), phalanx III-1 (13.86 mm), phalanx
III-2 (10.71 mm), phalanx III-3 (10.56 mm), pedal ungual III (5.25 mm),
phalanges IV-1 (9.19 mm), phalanges IV-2 (5.38 mm), phalanges IV-3 (5.58 mm),
phalanges IV-4 (5.82 mm), pedal unguals IV (3.85 mm)
Referred- (IVPP V12444; specimen of "Archaeoraptor liaoningensis"
in part; holotype of Archaeovolans repatriates) incomplete skull (~60
mm), partial mandibles, hyoid, several cervical vertebrae, few dorsal vertebrae
(6.4 mm), several dorsal ribs, synsacrum, partial scapulae (57 mm), partial
coracoids (38 mm), furcula (23 mm), sternum (48.2 mm), sternal ribs, humeri
(~78.4 mm), radii (72.7 mm), ulnae (78.1 mm), scapholunare, pisiform, distal carpal
III, carpometacarpi (one partial; mc I 7 mm, mc II ~36.9 mm), phalanx I-1 (~17
mm), manual ungual I (8 mm), phalanges II-1 (one partial; 17 mm), phalanges
II-2 (18 mm), manual unguals II, phalanx III-1, partial ilia, proximal pubis,
ischium, femur (~66 mm), tibiotarsus (78.1 mm), fibula, phalanx I-1 (8.4 mm),
tarsometatarsus (38.8 mm), phalanx II-1 (14.1 mm), phalanx II-2 (12.1 mm), phalanx
III-1 (14.7 mm), six pedal phalanges, three pedal unguals, body feathers, remiges
(Sloan, 1999)
(IVPP V13358) skull, mandibles, hyoid, seven cervical vertebrae, several dorsal
vertebrae, several dorsal ribs, gastralia, sacrum, two proximal caudal vertebrae,
scapulae, coracoids, furcula, sternum, humeri, radii, ulnae (74.3 mm), scapholunare, pisiform,
carpometacarpi, phalanges I-1, manual unguals I, phalanges II-1 (16.9 mm), phalanges II-2 (15.5 mm),
manual unguals II, phalanx III-1, ilium, pubes, ischium, femur, tibiotarsi,
tarsal?, metatarsal I, phalanges I-1, pedal unguals I, tarsometatarsi, phalanges
II-1, phalanges II-2, pedal unguals II, phalanges III-1, phalanges III-2, phalanges
III-3, pedal unguals III, phalanges IV-1, phalanges IV-2, phalanges IV-3, phalanges
IV-4, pedal unguals IV, gastroliths (<2 to 2.7 mm), body feathers (Zhou et
al., 2004)
(LHZA02-0008) partial skull (61.9 mm), anterior dentary, eighth cervical vertebrae,
three dorsal vertebrae, fragmentary synsacrum (34.5 mm), scapulae (49.5 mm),
coracoid (30.3 mm), furcula, humeri (70.1 mm), radii (69.4 mm), ulnae (70.2
mm), scapholunare, pisiform, carpometacarpi (mc I 5.5 mm, mc II 30 mm, mc III 29 mm),
phalanges I-1 (15.5 mm), manual unguals I (8.5 mm), phalanges II-1 (16.3 mm),
phalanges II-2 (15.8 mm), manual unguals II (7 mm), phalanx III-1 (8 mm), pubes
(51.4 mm), ischium (20 mm), femora (53 mm), tibiotarsi (68.7 mm), fibula (19
mm), metatarsal I, phalanx I-1 (8.2 mm), pedal unguals I (5.5 mm), tarsometatarsi
(35.5 mm), phalanges II-1 (13 mm), phalanges II-2 (10.3 mm), phalanges II-3
(9.5 mm), pedal unguals II (6.2 mm), phalanges III-1 (13.5 mm), phalanges III-2
(10.7 mm), phalanges III-3 (9.8 mm), pedal unguals III (7.5 mm), phalanges IV-1
(9.7 mm), phalanges IV-2 (9.3 mm), phalanges IV-3 (7.1 mm), phalanges IV-4 (6.1
mm), pedal unguals IV (5 mm) (Yuan, 2004)
Late Barremian-Early Aptian, Early Cretaceous
Jianshangou Beds of Yixian Formation, Liaoning, China
Holotype- (xhpm1205; holotype of Yanornis guozhangi) skull (55 mm), mandibles, hyoids, cervical series,
several dorsal vertebrae, dorsal ribs, uncinate processes, synsacrum (32 mm),
few caudal vertebrae, pygostyle (12 mm), partial scapulae (45 mm), coracoid,
furcula, sternum, humeri (72 mm), radii (74 mm), ulnae (74 mm), pisiform, carpometacarpi
(36 mm), phalanges I-1 (19 mm), manual unguals I (10 mm), phalanges II-1 (15
mm), phalanges II-2 (15 mm), manual unguals II (6 mm), phalanges III-1 (8 mm),
ilia, pubes (75 mm), ischia, femora (55 mm), tibiotarsi (68 mm), fibulae (44
mm), metatarsals I, phalanges I-1 (7 mm), pedal unguals I (5 mm), tarsometatarsi
(33 mm), phalanges II-1 (12 mm), phalanges II-2 (10 mm), pedal unguals II (6
mm), phalanges III-1 (14 mm), phalanges III-2 (10 mm), phalanges III-3 (8 mm),
pedal unguals III (6 mm), phalanges IV-1 (9 mm), phalanges IV-2 (7 mm), phalanx
IV-3 (6 mm), phalanx IV-4 (6 mm), pedal ungual IV (5 mm), three fish (Wang, Ji, Teng and Jin, 2013)
Late Valanginian-Middle Aptian, Early Cretaceous
Ningcheng, Yixian Formation, Inner Mongolia, China
Holotype- (IVPP V14606; holotype of Abitusavis lii)
fragmentary skull, incomplete mandibles, atlas, axis, eight cervical
vertebrae, eight dorsal vertebrae, dorsal ribs, uncinate processes,
synsacrum (30.76 mm), four caudal vertebrae, pygostyle (12.27 mm),
scapulae, coracoids (29.75 mm), furcula, incomplete sternum, sternal
ribs, humeri (75.19 mm), radii (72.22 mm), ulnae (76.56 mm), pisiform,
carpometacarpi (35.66 mm, mcI 6.67 mm), phalanx I-1, manual unguals I,
phalanges II-1 (17.15 mm), phalanges II-2 (14.89 mm), manual unguals II
(5.13 mm), phalanges III-1 (8.26 mm), ilia (one incomplete, one
fragmentary), pubes, femora (54.76 mm), tibiotarsi (71.44 mm), fibulae,
metatarsal I (5.75 mm), tarsometatarsi (37.28 mm), twelve pedal
phalanges, five partial pedal phalanges, four pedal unguals (Liu, 2008)
Barremian-Albian, Early Cretaceous
Jehol Group, Liaoning?, China
?(IMMNH-PV00021) (adult) skull, mandibles, hyoid, cervical series,
dorsal vertebrae, partial dorsal ribs?, sacrum, caudal series,
pygostyle, scapulae, coracoids, partial furcula, fragmentary sternum,
humeri, radii, ulnae, pisiform, carpometacarpi, phalanx I-1, manual
ungual I, phalanges II-1, phalanges II-2, manual unguals II, phalanx
III-1, incomplete pubes, femora, tibiotarsi, metatarsal I,. phalanges
I-1, tarsometatarsi, pedal digits II, pedal digits III, pedal digits
IV, body feathers, remiges (Wang et al., 2020a)
?(IVPP V13259; paratype of Abitusavis lii) skull,
incomplete mandibles, hyoids, cervical vertebrae, dorsal vertebrae,
dorsal ribs, synsacrum, partial sternum, fragmentary pectoral elements,
humeri (75.4 mm), radii, ulnae (78.20 mm), proximal carpal,
carpometacarpi (36.10 mm), phalanges I-1, phalanges II-1 (~18.6 mm),
phalanges III-1, pubes, femora (56.10 mm), tibiotarsi (71.70 mm),
fibulae, metatarsals I, phalanges I-1, pedal unguals I, tarsometatarsi
(38.90 mm), phalanges II-1, phalanges II-2, pedal unguals II, phalanges
III-1, phalanges III-2, phalanges III-3, pedal unguals III, phalanges
IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4, pedal unguals IV,
feathers, teleost elements (Zhou, Clarke and Zhang, 2002)
?(STM 9-15) skull (72.2 mm), mandibles, hyoids, cervical series, dorsal series,
dorsal ribs, gastralia, synsacrum, caudal vertebrae, scapula (~57.8 mm), coracoids
(39 mm), partial furcula, sternal fragments, humeri (80 mm), radii, ulnae (85
mm), scapholunare, pisiform, carpometacarpi (~34 mm), phalanges I-1, manual unguals
I, phalanges II-1 (~16 mm), phalanges II-2, manual unguals II, phalanges III-1, phalanges
III-2, manual claw sheaths, partial ilia, pubes, ischium, femora (~51 mm; one
partial), incomplete tibiotarsi (~78 mm), fibulae (one partial), metatarsal
I, phalanx I-1, pedal ungual I, tarsometatarsus (39 mm), phalanx II-1, phalanx
II-2, pedal ungual II, phalanx III-1, proximal phalanx III-2, phalanx IV-1,
phalanx IV-2, phalanx IV-3, proximal phalanx IV-4, body feathers, two cf. Jinanichthys,
actinopterygian fragments (Zheng et al., 2014)
?(STM 9-19) skull (~62 mm), cervical series fused to cervical ribs, dorsal series,
dorsal ribs, synsacrum, caudal vertebrae, pygostyle, scapulae, coracoid, furcula,
humeri (76 mm), radii, ulnae (80 mm), pisiform, carpometacarpi (34.5 mm), phalanges
I-1, manual ungual I, phalanges II-1, phalanges II-2, manual unguals II, phalanges
III-1, pubes, femora (58 mm), tibiotarsi (73 mm), metatarsal I, phalanx I-1,
pedal ungual I, tarsometatarsi (38 mm), phalanges II-1, phalanges II-2, pedal
unguals II, pedal digits III, pedal phalanges IV, retrices, body feathers, Protopspherus
scales (Zheng et al., 2014)
(STM 9-26) skull (72 mm), sclerotic plates, mandibles, hyoid, cervical series,
dorsal series, dorsal ribs, caudal vertebrae, pygostyle, partial humerus (~78
mm), partial radius, partial ulna (~80 mm), incomplete manus, pubes, femur,
tibiotarsi, phalanx I-1, pedal ungual I, tarsometatarsi, pedal phalangeal fragments,
cf. Jinanichthys (Zheng et al., 2014)
(STM 9-37) skull (68 mm), sclerotic plates, mandibles, hyoids, cervical vertebrae,
dorsal vertebrae, dorsal ribs, gastralia, scapula (~45 mm), furcula, sternum,
humeri (79 mm), radii, ulnae (86 mm), carpometacarpi (~38 mm), phalanges I-1,
manual unguals I, phalanges II-1 (~18 mm), phalanx II-2, phalanx III-1, pubes, femora
(~55 mm), tibiotarsi (74 mm), proximal tarsometatarsi, actinopterygian fragments
(Zheng et al., 2014)
?(STM 9-46) skull (~68 mm), several posterior cervical vertebrae, dorsal series,
dorsal ribs, synsacrum, caudal vertebrae, pygostyle, scapulae (50 mm), coracoids
(34 mm), partial furcula, partial sternum, humeri (80 mm), radii, ulnae (86
mm), scapholunares, pisiform, carpometacarpi (~39 mm), phalanx I-1, phalanges II-1 (~19 mm),
ilia, pubes, partial ischium, femora (57 mm), tibiotarsi (74 mm), fibula, metatarsal
I, phalanx I-1, pedal ungual I, tarsometatarsi (40 mm), phalanx II-1, phalanx
II-2, pedal ungual II, phalanx III-1, phalanx III-2, phalanx III-3, phalanx
IV-1, phalanx IV-2, phalanx IV-3, phalanx IV-4, pedal ungual IV, actinopterygian
fragments (Zheng et al., 2014)
?(STM 9-49) skull (~61 mm), mandible, cervical series, dorsal series, dorsal
ribs, gastralia, humeri (72 mm), radii, ulnae (~80 mm), carpometacarpi, phalanges
I-1, manual unguals I, phalanges II-1, phalanges II-2, manual unguals II, phalanges
III-1, phalanges III-2, pubes, femora (~50 mm), tibiotarsi (~75 mm), fibulae
(one partial), phalanges I-1, pedal unguals I, tarsometatarsi, phalanx II-1,
phalanx II-2, pedal ungual II, phalanx III-1, phalanx III-2, phalanx III-3,
pedal ungual III, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanx IV-4, pedal
ungual IV, pedal digits, cf. Jinanichthys, actinopterygian fragments
(Zheng et al., 2014)
?(STM 9-52) skull (68 mm), sclerotic ring, mandibles, cervical series, dorsal
series, dorsal ribs, scapula (48 mm), coracoid (31 mm), furcula, humeri (~68
mm), radii, ulnae (72 mm), pisiform, carpometacarpi (41 mm), phalanges I-1, manual
unguals I, phalanx II-1 (~22 mm), phalanx II-2, manual ungual II, phalanx III-1, ilium,
pubes, femora (50 mm), tibiotarsi (68 mm), pedal ungual I, tarsometatarsi (35
mm), phalanges II-1, phalanges II-2, pedal unguals II, pedal phalanges, pedal
unguals, remiges, actinopterygian fragments (Zheng et al., 2014)
Diagnosis-
(after Wang et al., 2020b) dentary with [more] vertically oriented
anterior margin (actually about 61-64 degrees in the holotype, 68
percent in IVPP V12444 and
60-63 degrees in IVPP V13358 versus about 42-50 degrees in
Similiyanornis); synsacrum with ventral groove; coracoid with distally expanded procoracoid process (also in Schizooura, Yixianornis).
Other diagnoses- Zhou and Zhang (2001) listed several characters
in their diagnosis. A straight dentary is also present in Songlingornis,
Ichthyornis, Similiyanornis and hesperornithids. According to their figure, the dentary
is only 43% of skull length (which is similar to other basal euornithines),
not 66%. The number of dentary teeth (20) is similar to Similiyanornis (~20) and Ichthyornis (21-24).
Elongate cervical vertebrae are also present in Patagopteryx, Similiyanornis, hesperornithines
and ambiortiforms. While stated to be heterocoelous by Zhou and Zhang (2001),
the cervicals were coded as semiheterocoelous by Zhou and Zhang (2005) and amphicelous
by Clarke et al. (2006). Their true state remains to be determined. A synsacrum
with nine vertebrae is also known in Similiyanornis, Mengciusornis, Yixianornis and Patagopteryx.
The short pygostyle is similar to most euornithines. Posterior sternal fenestrae are present in Piscivoravis, Iteravis, Gansus, Yixianornis
and Songlingornis as well. The posterolateral sternal process is not
distally semicircular, but rather slightly convex as in Yixianornis and
Archaeorhynchus. A forelimb/hindlimb ratio (hum+uln+carp/fem+tib+tars)
of ~110% (actually 106-122%) is also present in Similiyanornis (107%). The manus is shorter than the ulna, but contra Zhou
and Zhang is not shorter than the radius. In any case, the carpometacarpo-ulnar
ratio (43-49%) is very similar to Similiyanornis (46%), Yixianornis (42%), Patagopteryx
(44%), Archaeorhynchus (45%), and Gansus (48%). The tarsometatarsus
is completely fused in almost all euornithiness. The third pedal digit is similar
in length (107-115% of tarsometatarsal length) to Patagopteryx (~106%)
and Gansus (102-116%). Proximal pedal phalanges are longer and more robust
than distal phalanges in other basal euornithines where known.
Czerkas and Xu (2002) diagnosed Archaeovolans based on several characters.
The number of premaxillary teeth (four) is plesiomorphic, as is them being larger
than dentary teeth. The large number of dentary teeth (at least eighteen) is
dealt with above. While they claim uncinate processes were absent, the ribcage
is only partially articulated and has several small transverse elements which
could be uncinates. The "strikingly modern" pectoral girdle is vague
but is shared with more derived birds in any case. The supposedly short sternal
keel as illustrated is not present in the specimen, which shows an elongate
keel as in other Yanornis specimens and basal euornithines. The scapholunare
and pisiform are said to be "well developed", but this is vague and
they are comparable to other basal euornithines. The lack of a long ventral
ramus is plesiomorphic and shared with Similiyanornis, Yixianornis and Gansus.
Finally, the lack of a projected ventral carpal trochlea is plesiomorphic and
shared with other basal euornithines such as Yixianornis and Patagopteryx.
Clarke et al. (2006) listed humerus longer than scapula as diagnostic, but this is present in all basal euornithines except Patagopteryx, Yixianornis and Apsaravis.
Wang et al. (2020b) listed several characters differing from their new yanornithiforms Abitusavis (here synonymized with Yanornis) and/or Similiyanornis
but a premaxillary body anterior to the naris shorter than the
subnarial process of the premaxilla is not present in some specimens
(e.g. xhpm1205). Two sternal characters listed as differing from Abitusavis
are just adult characters compared to the latter and are present in
many other basal ornithouromorphs- sternum bearing a pair of
anterolateral processes (also in e.g. Similiyanornis, Jianchangornis, Archaeorhynchus, songlingornithids, Yumenornis); posterolateral sternal processes distally expanded (also in e.g. Jianchangornis, Archaeorhynchus, Piscivoravis, songlingornithids, Yumenornis; unknown in Similiyanornis). An elongate forelimb with an intermembral index
(hum+uln/fem+tib) of 1.27
only refers to the holotype, with the range of ratios actually
1.09-1.27, which overlaps 1.12 in Similiyanornis. A bicipital crest of the humerus with a pit-shaped fossa [anteriorly] is also present in Similiyanornis, Jianchangornis, Schizooura, Iteravis and Apsaravis.
The "Archaeoraptor" debacle- The specimen IVPP V12444 was fraudulently
combined with the tail of the Microraptor zhaoianus holotype by a Chinese
farmer. It was smuggled out of the country then sold at the 1998 Tuscon Gem
Show to Czerkas. Currie recognized the legs were part and counterpart slabs
of the same bones, while Rowe and Aulenback independently verified the composite
nature of the specimen. National Geographic announced the specimen in a press
conference in October, and in November, Sloan (1999) published a paper using
the name "Archaeoraptor liaoningensis". This was a nomen nudum because
it explicitely stated the taxon was to be described formerly in an official
publication. That official publication was to have been in Science or Nature,
but both journals rejected it. In April, Olson (2000) published an article purporting
to officially describe "Archaeoraptor" and attach that name to the
dromaeosaurid tail (with the latter as the lectotype). Several months later
in December, Xu et al. (2000) officially named Microraptor zhaoianus
based on the dromaeosaurid tail and associated anterior part of the skeleton
Xu had discovered. At this time, Olshevsky (DML, 2000) noted that Olson's publication
predated Xu et al.'s, and he believed that this made Microraptor a junior
synonym of "Archaeoraptor". Several days later, Creisler (DML, 2001)
pointed out the Olson's attempt to name "Archaeoraptor" was invalid
because the ICZN requires a diagnosis in a valid publication, while Olson merely
referenced the invalid article by Sloan. Creisler further indicated Olson cannot
designate a lectotype without a valid publication defining a holotype first.
Thus "Archaeoraptor" is still a nomen nudum, despite Olson's efforts,
and Microraptor zhaoianus is the valid name for the IVPP V 12330 dromaeosaurid.
The specimen was returned to the IVPP in May, 2000 and Zhou and Zhang were asked
to work on the euornithine section. They noticed the similarity with Yanornis
shortly before completing their paper on that taxon in December 2000. Rowe et
al. (2001) detailed the composite nature of the specimen, recognizing it was
from at least two, and possibly up to five animals. They noted the euornithine
section (IVPP V 12444) was to be described by Xu (in prep.), which later appeared
as Czerkas and Xu (2002). These authors described the specimen as a new taxon
of euornithine (as Ornithurae) bird- Archaeovolans repatriates. Czerkas and Xu noted
in an addendum that the recently described Yanornis martini was extremely
similar and might be congeneric, though they also thought differences were present.
Zhou et al. published their work in 2002, noting that both anatomy and proportions
were nearly identical in the holotypes for the two species and synonymized them.
Given the recent description of Similiyanornis, IVPP V12444 can be referred to Yanornis based on the vertical anterior dentary margin, expanded procoracoid process (also noted by Wang et al., 2020b), and lack of Similiyanornis'
enlarged anterior dentary tooth, anterior dentary foramen, and elongate
manual phalanx II-1 (46% of carpometacarpus versus 67% in Similiyanornis). While Rowe et al. found no evidence the right femur and both tibiotarsi, fibulae
and pes belong to the same individual as the body, Zhou et al. (2002) confirmed
they do.
Yanornis gouzhangi- Wang et al. (2013) described a supposedly new Yanornis species, Y. guozhangi, based on complete skeleton xhpm1205. Contra their diagnosis, the "large and strong deltoid crest,
which is almost half the length of the shaft" is the same as in Yanornis martini. The pubic symphysis is noted to be shorter than the Y. martini holotype, at 24% compared to 35%, but it falls within the range of variation of Y. martini
with LHZA02-0008 having a 37% ratio and IVPP V13259 having a 21%
ratio. The fibula was stated to be longer, at "2/3 the length of the
tibiotarsus" (actual ratio 65%) compared to 39% in the Y. martini
holotype. Most specimens cannot be checked but the ratio in
LHZA02-0008 is 28% and that of IVPP V14606 at least 39%. Wang et al.
state "the tarsometatarsus is short and completely fused, less than
half the length of the tibiotarsus", but all euornithines have
completely fused tarsometatarsi and the tarsometatarsotibiotarsal ratio
(49%) is actually greater than the ratio in the Y. martini
type (46%) and falls within the range of other specimens (49-54%).
With the longer fibula being the only valid proposed difference, Y. guozhangi is synonymized with Y. martini. It also shares Yanornis' dentary with a vertically oriented anterior margin and lacks Similiyanornis'
large anterior dentary tooth and long manual phalanx II-1 (67% of
carpometacarpus versus 42% in xhpm1205). Wang et al. reached the
same conclusion, stating "all of the features originally used to
diagnose this taxon are present in Yanornis martini",
"putative differences between these two taxa pertain to subtle limb
proportions" and "our re-examination indicates that the former is
morphologically identical to Yanornis martini."
Abitusavis- Liu (2008) described IVPP V14606 in their thesis as an example of Yanornis martini.
It was later described by Wang et al. (2020b) as a new taxon of
yanornithid, Abitusavis lii. However, most of their listed
diagnostic characters compared to Yanornis are flawed. Two
characters are listed as differing from Similiyanornis, but being
shared with Yanornis- synsacrum bearing a ventral groove; coracoid with
distally expanded procoracoid process. Wang et al. also list
intercotylar eminence of tarsometatarsus absent
in their diagnosis, but the weak convexity is only slightly less
prominent than in Similiyanornis while Yanornis
(e.g. IVPP V12558, xhpm1205) lacks any convexity. A distal vascular
foramen which is proximally located is listed in supposed contrast with
Similiyanornis, but the labeled distal vascular foramen in the latter is just the gap between trochlea III and IV also seen in Abitusavis.
The area around the true distal vascular foramen is too poorly
preserved to score in other yanornithiforms. They also list margins of
pedal ungual flexor tubercles step-like instead of circular but this is
similar to some Yanornis
(e.g. IVPP V13358) so is probably individual variation. Two
sternal characters (sternum without anterolateral processes;
posterolateral processes of sternum not expanded distally) are typical
of young ornithothoracines, which agrees with the smaller size of
Abitusavis (humerus 88% of Yanornis holotype). Notably the
intermediate-sized IVPP V12444 (92%) only has slightly expanded
posterolateral processes. The supposed posterodorsally elongate
retroarticular process strongly reseembles the medial articular process
of Ichthyornis, down to the slight anteromedial convexity for the
medial condyle, suggesting the posterior mandible rotated into ventral
exposure. This would not differ from Yanornis specimens preserved
in lateral view but is similar to the Similiyanornis type as
interpreted by Liu. The synsacrum having one less vertebra
incorporated than the Yanornis holotype is a character known to vary
individually in Ichthyornis.
The potentially most diagnostic character is the paired M. cranialis
tibialis tubercles on metatarsals II and III, unlike the Yanornis
holotype with its proximodistally poorly defined tubercle on metatarsal
II and at best very small tubercles on metatarsal III. Given the
individual variation in other Mesozoic birds, this is considered
insufficient to support a new species, and Abitusavis lii is here placed as a junior synonym of Yanornis martini.
Zhou et al. (2002) stated "a recently discovered specimen of Yanornis
(IVPP V13259) contains preserved macerated fish remains, including a
teleost vertebra, fin rays and opercular fragments" and figured a small
section of it. Wang et al. (2020b) referred it to their new taxon Abitusavis
based on the intermembral index (hum+uln/fem+tib of 1.20 in both),
femoral/tibiotarsal ratio (0.78 vs. 0.77 in holotype) and absent
intercotylar eminence. However, the ratios fall within the range
of variation of Yanornis while the intercotylar eminence is also absent in that taxon as noted above. It is assigned to Yanornis here based on the short manual phalanx II-1 unlike Similiyanornis.
Referred specimens-
The paratype (IVPP V10996) has yet to be described but was figured by
Wang et al. (2020b), who correctly noted "few diagnostic features can be
identified from this specimen" and referred it to Yanornithidae
indet.. Indeed no characters of Yanornis
or Similiyanornis can be seen, so it is placed in Yanornithiformes indet. here.
Yuan (2004) described another specimen (LHZA02-0008) as Yanornis martini which is notable
in having four phalanges on each pedal digit II and a specimen of the osteoglossomorph
Jinanichthys in its mouth. It is not Similiyanornis
based on the lack of an enlarged dentary tooth and short manual phalanx
II-1 (54% of carpometacarpus), so is referred to Yanornis here.
Zhou et al. (2004) briefly described a specimen
with gastroliths (IVPP V13358), which was later illustrated by Zhou and Zhang
(2006) and mentioned another specimen (IVPP V13278) which was later made the holotype of Similiyanornis brevipectus. Wang et al. (2020b) correctly concluded IVPP V13358 was Yanornis instead of Similiyanornis based on the more vertical anterior dentary edge, lack of Similiyanornis' enlarged dentary tooth and anterior foramen and short manual phalanx II-1.
Zheng et al. (2013) briefly described STM 9-5 which they referred to Yanornis, but it is referred to Yanornithiformes indet. here.
Zheng et al. (2014) described fish remains in ten new specimens. Of
these, note STM 9-52 has only one large phalanx in digit II of its
right manus, which if not a developmental anomaly is likely to be a
forgery. Most of right pedal digit III seems to be fake, lending
credence to the latter possibility. Wang et al. (2020b) stated "until
adequate preparation and detailed comparative study are conducted, we
suggest the aforementioned 10 specimens are tentatively referred to
Yanornithidae indet." However, STM 9-15, 9-19, 9-46, 9-49 and
9-52 can be tentatively referred to Yanornis
based on the short manual phalanx II-1 (46%, ~45%, 48%, ~53% and 52% of
carpometacarpus respectively; but see STM 9-18), while STM 9-26 can be
referred to it based on the more vertical anterior dentary margin and
lack of an enlarged tooth, STM 9-37 based on the lack of an enlarged
anterior dentary tooth and short phalanx II-1 (48%). STM 9-18,
9-31 and 9-51 are placed in Yanornithiformes indet. here though, with
the caveat 9-18 appears to show a mix of Yanornis and Similiyanornis characters.
Wang et al. (2020) described the hsitology of IMMNH-PV00021 (perhaps
from Inner Mongolia like IVPP V14606 based on it being in the Inner
Mongolia Museum of Natural
History) as Yanornis, which it may be based on the short manual phalanx II-1 (~51% of carpometacarpal length).
Miscoded originally? Zhou and Zhang (2005) were the first authors to
code Yanornis, but You et al. (2006) changed numerous codings based on
personal observation of the holotype by Chiappe and O'Connor. Clarke et al.
(2006) later coded Yanornis again based on the holotype, IVPP V12444,
V13259 and V13358. These include making the following states uncertain- anterior
premaxillary fusion (stated to be present by Zhou et al., 2002 and coded so
by Clarke et al.); fusion of frontoparietal suture (appears absent in the figure
of the holotype; also uncertain in Clarke et al.); quadrate pneumaticity including
cluster of foramina on dorsal process (also uncertain in Clarke et al.); presence
of external mandibular fenestra (appears absent in the figure of the holotype;
also uncertain in Clarke et al.); coely of cervical vertebrae (stated to be
heterocoelous by Zhou and Zhang, 2001; coded as semihetercoelous by Zhou and
Zhang, 2005; coded as amphicoelous by Clarke et al.); presence of large hypapophyses
on mid dorsal vertebrae (appears absent in IVPP V12444; coded as absent by Clarke
et al.); number of dorsal vertebrae (also uncertain in Clarke et al.); presence
of notarium (seems absent from figures of holotype and IVPP V12444; coded as
absent by Clarke et al.); number of sacral vertebrae (stated to be and illustrated
as nine by Zhou and Zhang, 2001; coded as nine by Clarke et al.); number of
sacrals with dorsally directed diapophyses (stated to be and illustrated as
none by Zhou and Zhang, 2001; coded as none by Clarke et al.); length and presence
of pygostyle (the supposed pygostyle of the holotype has no features identifying
it as such- Senter, pers. comm.); median proximity of coracoid sulci on sternum
(coded as close or overlapping by Clarke et al.); presence of intermuscular
lines on sternum (also uncertain in Clarke et al.); lateral excavation of furcula
(coded as absent by both Clarke et al. and Nesbitt et al., 2009); pointed epicleidea
(coded as absent by both Clarke et al. and Nesbitt et al., 2009; but seemingly
present in IVPP V12444 and V13358); concavity of dorsal coracoid surface (stated
to be deeply concave distally by Zhou and Zhang, 2001; coded as flat by Clarke
et al.); pneumaticity of coracoid (coded as absent by Clarke et al.); position
of glenoid relative to acrocoracoid (stated to be ventral by Czerkas and Xu
and coded as such by Clarke et al.); curvature of acrocoracoid (coded as medially
hooked by Clarke et al.); presence of supracoracoid foramen (also uncertain
in Clarke et al.); whether the supracoracoid foramen opens into a medial groove
(unknown since the foramen's presence is uncertain); angle between scapula and
coracoid (less than 90 degrees in IVPP V13358; coded as such by Clarke et al.);
length of acromion (illustrated as long in the holotype, but as short in IVPP
V12444 and V13358; coded as long by Clarke et al.); curvature of acromion (stated
to be curved by Zhou et al., 2002; coded as straight by Clarke et al.); presence
and morphology of capital groove and ventral tubercle (also uncertain in Clarke
et al.; all specimens seem to be preserved with humeri in anterior view); presence
of anterior concavity on humeral head (actually already coded unknown by Zhou
and Zhang, 2005; but coded absent by Clarke et al.); development of bicipital
crest (stated to be ball-shaped by Zhou and Zhang, 2001 and well developed by
Czerkas and Xu; coded as enlarged by Zhou and Zhang and moderate by Clarke et
al.); presence of brachial fossa on humerus (also uncertain in Clarke et al.);
demarkation of muscle origins on the dorsodistal humerus (also uncertain in
Clarke et al.); presence of scapulotricipital and humerotricipital grooves (also
uncertain in Clarke et al.; all specimens seem to be preserved with humeri in
anterior view); separation of ulnar cotyla (also uncertain in Clarke et al.);
semilunar morphology of dorsal ulnar condyle (visible in IVPP V12444; stated
to be present by Zhou and Zhang, 2001 and coded as such by Clarke et al.); morphology
of ventroposterior surface of radius (apparently grooved in both IVPP V12444
and V13358; coded as flat or scarred by Clarke et al.); length of pisiform rami
(poorly developed in IVPP V12444 and coded as such by Clarke et al.); comparative
lengths of dorsal and ventral pisiform rami (coded as subequal by Clarke et al.);
width of metacarpal III (is approximately 50% in the holotype and IVPP V12444;
seems much narrower in Zhou and Zhang's illustration of IVPP V13358, but is
wider in the photo; coded as narrower by Clarke et al.); convexity of medial
metacarpal I edge (concave in IVPP V12444; also coded uncertain in Clarke et
al.); presence of internal index process of manual phalanx II-2 (absent in IVPP
V13358 and coded as such by Clarke et al.); dorsal fusion of ilia (clearly absent
in the holotype and coded as such by Clarke et al.); anterior extent of ilium
(does not overlap last dorsal vertebra in the holotype and coded as such by
Clarke et al.); presence of cuppedicus fossa on ilium (also coded uncertain
in Clarke et al.); size and presence of posterior trochanter (also coded uncertain
in Clarke et al.); fusion of tibiotarsus (coded as completely fused by Clarke
et al.); comparative anterior projection of tibiotarsal condyles (also coded
uncertain in Clarke et al.); presence of supratendinal groove (coded as absent
by Clarke et al.); presence of retinaculi extensor tubercle on distal tibiotarsus
(also coded uncertain in Clarke et al.); comparative width of tibiotarsal condyles
(also coded uncertain in Clarke et al.); medial constriction of tibiotarsal
condyles in distal view (coded as constricted by Clarke et al.); width of tibiotarsal
intercondylar groove in distal view (coded as wide by Clarke et al.); extent
of cartilaginous tibial sulcus (actually already coded unknown by Zhou and Zhang,
2005); distal tibiotarsal width compared to midshaft width (coded as subequal
by Clarke et al., but this seems untrue in most birds including Yanornis,
making interpretation of Clarke's character problematic); distal contact between
fibula and tarsus (absent in all specimens; as coded by Clarke et al.); hypotarsal
development (coded as absent or lacking crests and foramina by Clarke et al.);
development of fossa for metatarsal I (also coded uncertain in Clarke et al.);
ginglymoidy of metatarsal II (seems rounded in IVPP V13358); relative transverse
width of metatarsals (subequal in IVPP V13358 and coded as such by Clarke et
al.); number of distal vascular foramen exits in tarsometatarsus (also coded
uncertain in Clarke et al.).
They also changed several codings- dentary symphysis without broad dorsally
facing surface (which agrees with Czerkas and Xu, 2002); posterior dentary unforked
(as it appears in the figure of the holotype); Meckelian groove not covered
by splenial (which agrees with Czerkas and Xu, 2002); presence of lateral foramina
in the dorsal centra (though described as pleurocoels by Zhou and Zhang and
Czerkas and Xu, their size makes them more likely to be fossae as coded by Clarke
et al.); lateral coracoid process absent (illustrated as present by Zhou and
Zhang, 2001 and Zhou et al., 2002; coded as present by Clarke et al., 2006);
ulna shorter than humerus (longer in specimens with exactly measured elements;
as coded by Clarke et al.); dorsal ulnar cotyla not convex (coded uncertain
by Clarke et al.); ulnar brachial scar present (also coded as present by Clarke
et al.); intermetacarpal space reaches proximally to metacarpal I (present in
all specimens; as coded by Clarke et al.); manual phalanx II-2 shorter than
II-1 (coded as longer by Clarke et al., but actually varies from 97-106%, making
it polymorphic); one proximal vascular foramen in tarsometatarsus (coded uncertain
by Clarke et al.); metatarsal I straight (coded as curved by Clarke et al.);
laterally placed m. tibialis cranialis tubercle on tarsometatarsus (as coded
by Clarke et al.); metatarsal trochlea II subequal or wider than trochlea III
and/or IV (Zhang and Zhou, 2001 state metatarsal II's trochlea is intermediate
in width between III and IV; which state this represents is confusing, as Clarke's
character has states compared to trochlea III AND/OR IV, so it agrees with parts
of states 1 and 2); metatarsal II shorter than metatarsal IV, but reaching distally
farther than base of metatarsal IV trochlea (as coded by Clarke et al; while
Zhou and Zhang's illustration appears to show subequal lengths, their text states
II is shorter).
References- Sloan, 1999. Feathers for T. rex?. National Geographic.
196(5), 98-107.
Olshevsky, DML 2000. https://web.archive.org/web/20200714090029/http://dml.cmnh.org/2000Dec/msg00720.html
Olson, 2000. Countdown to Piltdown at National Geographic: the rise and fall
of Archaeoraptor. Backbone, newsletter of the Department of Vertebrate Zoology,
National Museum of Natural History. 13(2), 1-3.
Xu, Zhou and Wang, 2000. The smallest known non-avian theropod dinosaur. Nature.
408, 705-708.
Creisler, DML 2001. https://web.archive.org/web/20200828153518/http://dml.cmnh.org/2001Jan/msg00092.html
Rowe, Ketcham, Deinson, Colbert, Xu and Currie, 2001. The Archaeoraptor forgery.
Nature. 410, 539-540.
Zhou and Zhang, 2001a. [Two new genera of ornithurine birds from the Early Cretaceous
of Liaoxi involved in the origin of modern birds.] Kexue Tongbao. 46(5), 371-377.
Zhou and Zhang, 2001b. Two new ornithurine birds from the Early Cretaceous of
western Liaoning, China. Chinese Science Bulletin. 46(1), 1-7.
Czerkas and Xu, 2002. A new toothed bird from China. Feathered Dinosaurs and
the Origin of Flight. 43-61.
Zhou, Clarke and Zhang, 2002. Archaeoraptor's better half. Nature. 420, 253-344.
Yuan, 2004. Further study of Yanornis martini (Ornithurae) from the Mesozoic
Jehol Biota in western Liaoning, China. Acta Geologica Sinica. 78(4), 464-467.
Zhou, Clarke, Zhang and Wings, 2004. Gastroliths in Yanornis: An indication
of the earliest radical diet-switching and gizzard plasticity in the lineage
leading to living birds? Naturwissenschaften. 91(12), 571-574.
Zhou and Zhang, 2005. Discovery of an ornithurine bird and its implication for
Early Cretaceous avian radiation. Proceedings of the National Academy of Sciences.
102(52), 18998-19002.
Clarke, Zhou and Zhang, 2006. Insight into the evolution of avian flight from
a new clade of Early Cretaceous ornithurines from China and the morphology of
Yixianornis grabaui. Journal of Anatomy. 208, 287-308.
Zhou and Zhang, 2006. Mesozoic birds of China- A synoptic review. Vertebrata
PalAsiatica. 44(1), 60-98.
Liu, 2008. A new species of Yanornis and its phylogenic relationships. MS thesis, Chinese Academy of Sciences. 51 pp.
Nesbitt, Turner, Spaulding, Conrad and Norell, 2009. The theropod furcula. Journal
of Morphology. 270, 856-879.
Wang, Ji, Teng and Jin, 2013. A new species of Yanornis
(Aves: Ornithurae) from the Lower Cretaceous strata of Yixian, Liaoning Province.
Geological Bulletin of China. 32(4), 601-606.
Zheng, Zhou, Wang, Zhang, Zhang, Wang, Wei, Wang and Xu, 2013. Hind wings in
basal birds and the evolution of leg feathers. Science. 339, 1309-1312.
Zheng, O'Connor, Huchzermeyer, Wang, Wang, Zhang and Zhou, 2014. New specimens
of Yanornis indicate a piscivorous diet and modern alimentary canal.
PLoS ONE. 9(4), e95036.
Wang, O'Connor, Pan and Zhou, 2017. A bizarre Early Cretaceous
enantiornithine bird with unique crural feathers and an ornithuromorph
plough-shaped pygostyle. Nature Communications. 8:14141.
Bailleul, O'Connor and Zhou, 2019. Origin of the avian predentary and
evidence of a unique form of cranial kinesis in Cretaceous
ornithuromorphs. Proceedings of the National Academy of Sciences. 116(49), 24696-24706.
Wang, Hao, Kundrat, Liu, Uesugi, Jurasekova, Guo, Hoshino, Li, Monfroy,
Zhou, Fabriciova, Kang, Wang, Si, Gao, Xu and Li, 2020a (online 2019).
Bone tissue histology of the Early Cretaceous bird Yanornis:
Evidence for a diphyletic origin of modern avian growth strategies
within Ornithuromorpha. Historical Biology. 32(10), 1422-1434.
Wang, Li, Liu and Zhou, 2020b. Two new Early Cretaceous ornithuromorph
birds provide insights into the taxonomy and divergence of
Yanornithidae (Aves: Ornithothoraces). Journal of Systematic
Palaeontology. 18(21), 1805-1827.
Bailleul and Zhou, 2021. SEM analyses of fossilized chondrocytes in the extinct birds Yanornis and Confuciusornis: Insights on taphonomy and modes of preservation in the Jehol biota. Frontiers in Earth Science. 9, 718588.
Similiyanornis Wang, Li, Liu and Zhou, 2020
S. brevipectus Wang, Li, Liu and Zhou, 2020
= Yanornis "brevipectis" Liu, 2008
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Holotype- (IVPP V13278) skull
(51.44 mm), mandibles (49.4 mm), hyoids, nine postaxial cervical
vertebrae (9.7, 9.8, 11.7, 12.4, 13.8, ~9.1, ~9.6, ~8.4 mm), two
posteriormost dorsal vertebrae, partial dorsal ribs, synsacrum (31.4
mm), several caudal vertebrae, pygostyle (9.92 mm), scapula, coracoids
(28.74 mm), partial furcula, incomplete sternum, sternal ribs, humeri
(67.7, 64.8 mm), radii (65.38, 65.4 mm), ulnae (67.9, 68.0 mm),
scapholunare, pisiform, carpometacarpus (31.05 mm, mcI 6.85 mm),
phalanx I-1 (15.37 mm), manual ungual I (8.29 mm), phalanx II-1 (20.65
mm), phalanx II-2 (10.17 mm), manual ungual II (5.86 mm), phalanx III-1
(8.39 mm), ilia (30.3 mm), pubes (49.7, 46.1 mm), ischia (18.3, 20.2
mm), femora (54.97, 49.3 mm), tibiotarsi (61.5, 59.2 mm), fibula (~34.3
mm), metatarsal I, incomplete phalanx I-1 (~8.3 mm), tarsometatarsi
(34.3, 31.8 mm), incomplete phalanges II-1 (11.05 mm), phalanx II-2
(8.95 mm), incomplete pedal ungual II, phalanges III-1 (one incomplete;
12.79 mm), phalanges III-2 (8.97, 9.2 mm), phalanges III-3 (8.51, 8.6
mm), pedal unguals III (3.72 mm), phalanges IV-1 (one partial; 8.24
mm), phalanges IV-2 (7.23, 7.2 mm), phalanges IV-3 (6.08, 6.1 mm),
phalanges IV-4 (6.29, 6.1 mm), pedal unguals IV (4.83, 5.0 mm), body
feathers, remiges, retrices
Diagnosis- (after Wang et al., 2020) dentary having a minute alveolus near the anterior tip (also in Hesperornis);
first dentary tooth hypertrophied; tapered procoracoid process on
coracoid; manual phalanx II-1 over two-thirds of carpometacarpus length
(67% vs. 42-52% in Yanornis).
Other diagnoses- Wang et al. (2020) listed a lateral foramen at the anterior tip of the premaxilla, but this is also present in some Yanornis (e.g. xhpm1205).
A subnarial process of the premaxilla shorter than the premaxillary
body anterior to the naris was said to be diagnostic, but is also
present in some Yanornis (IVPP V13259, xhpm1205). Contra their statement "The lacrimal is poorly
preserved in all the specimens that can be confidently referred to Yanornis
martini", the supposedly diagnostic T-shaped lacrimal bearing a slender
posterodorsal process is also present in xhpm1205. They listed two surangular foramina as diagnostic, but Yanornis may have these as well based on xhpm1205. They stated
cervical prezygapophyses longer than postzygapophyses as diagnostic,
but this is only visible in two anterior cervicals and absent in the
last preserved cervical, comparable to IVPP V13259 where two anterior cervicals have longer prezygapophyses, a
mid cervical is intermediate and three posterior cervicals have longer
postzygapophyses. A large femorotibiotarsal ratio of 85% was
listed as diagnostic, but while the type of Yanornis has a 68% ratio, other specimens have ratios of 81% (xhpm1205) and 85% (IVPP V12444).
Wang et al. listed bicipital crest of humerus without a pit-shaped
fossa but the right humerus seems to have an anterior fossa, albeit
larger and more triangular than Yanornis' holotype. They also listed an enlarged flexor tuber of pedal ungual IV, but this minor difference is similar to some Yanornis (e.g. xhpm1205) but not others (e.g. IVPP V13358) so is probably individual variation.
Comments- Zhou et al. (2004) first mention IVPP V13278 as one of the several Yanornis martini
"completely, or partially, articulated specimens with minimal or no
evidence of postmortem disturbance. No gastroliths are known from any
of these specimens." Liu (2008) described this as a new species
of Yanornis, Y. "brevipectis", in their MS thesis. Wang et al. (2020) officially described it as a new genus as well, Similiyanornis brevipectus.
Differences in interpretation from the thesis include longer
posterodorsal premaxillary processes, reidentifying the mesethmoid as a
lacrimal, recognizing a mandible without an external fenestra, and
recognizing the sternum is broken posteriorly instead of being shorter
than in Yanornis (despite
retaining a version of its original species name "brevipectis").
Notably, Liu's Table 3.1 shows the forelimb measurements in Wang et al.
are averages of right and left sides.
References-
Zhou, Clarke, Zhang and Wings, 2004. Gastroliths in Yanornis: An indication
of the earliest radical diet-switching and gizzard plasticity in the lineage
leading to living birds? Naturwissenschaften. 91(12), 571-574.
Liu, 2008. A new species of Yanornis and its phylogenic relationships. MS thesis, Chinese Academy of Sciences. 51 pp.
Wang, Li, Liu and Zhou, 2020. Two new Early Cretaceous ornithuromorph
birds provide insights into the taxonomy and divergence of
Yanornithidae (Aves: Ornithothoraces). Journal of Systematic
Palaeontology. 18(21), 1805-1827.
unnamed clade (Yixianornis grabaui + Gansus yumenensis + Passer domesticus)
Guildavis Clarke, 2004
Definition- (Guildavis tener <- Ichthyornis dispar, Struthio
camelus, Tetrao major, Vultur gryphus) (modified from Clarke, 2004)
= "Guildavis" Clarke, 2002
G. tener (Marsh, 1880) Clarke, 2004
Definition- (the species that includes YPM 1760) (Clarke, 2004)
= Ichthyornis tener Marsh, 1880
= "Guildavis" tener (Marsh, 1880) Clarke, 2002
Cretaceous
Wallace County, Kansas, US
Holotype- (YPM 1760) partial synsacrum (~17 mm)
Other diagnoses- Clarke (2004) distinguished this taxon from Ichthyornis
based on two characters. The first is the presence of parapophyses on the first
sacral, which are also found in Gansus and Aves. The second is the presence
of wider iliosacral sulci, but this is also seen in Patagopteryx, Gargantuavis,
Zhyraornis and Gansus.
Comments- Marsh (1880) named this as a new species of Ichthyornis
based on a synsacrum discovered in 1879, but never illustrated or described
the species. He referred a distal humerus (YPM 1738) and coracoid (YPM 1766)
to Ichthyornis tener without comment, but Clarke (2004) showed these
are referrable to I. dispar. Brodkorb
(1967) incorrectly believed the humerus was YPM 1760, as Marsh never states
which element YPM 1760 is and references a figure of the humerus. Clarke (2002)
removed the holotype from Ichthyornis and described it as the new genus
"Guildavis", which was published by her in 2004. Clarke noted Guildavis
could not be compared to the probably contemporaneous Apatornis and Iaceornis
besides being smaller, so may be synonymous with either of these taxa.
Clarke (2004) found Guildavis to be more derived than Ichthyornis
based on the parapophysis on the first sacral, but this is now known to be present
in the more basal Gansus as well. Similarly, Clarke found Guildavis
to be excluded from Aves due to its amphicoelous anterior sacral articular surface,
but some crown birds including most charadriiforms have this as well, and Clarke
did not include any neoavians in her analysis.
References- Marsh, 1880. Odontornithes: a monograph on the extinct toothed
birds of North America. United States Geological Exploration of the 40th Parallel.
Washington, DC: U.S. Government Printing Office. 201 pp.
Brodkorb, 1967. Catalogue of fossil birds: part 3 (Ralliformes, Ichthyornithiformes,
Charadriiformes). Bulletin of the Florida State Museum (Biological Sciences).
11, 99-220.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT, 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
unnamed ornithuromorph (Parris and Hope, 2002)
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Material- (NJSM 15065) proximal scapula
Comments- This specimen closely resembles both Ambiortus and Lithornis
in the flattened, styloid, ventrally bent acromion. It may resemble the former
in fusing the coracoid tubercle to the cranial end of the humeral facet. Parris
and Hope (2002) tentatively referred it to Palaeognathae, but based on Clarke's
(2002) placement of Ambiortus outside that clade, it is assigned to a
more inclusive clade here.
References- Clarke, 2002. The morphology and systematic position of Ichthyornis
Marsh and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT, 532 pp.
Parris and Hope, 2002. New interpretations of the birds from the Navesink and
Hornerstown Formations, New Jersey, USA (Aves: Neornithes). In Zhou and Zhang
(eds.). Proceedings of the 5th Symposium of the Society of Avian Paleontology
and Evolution, Beijing, 1-4 June 2000. 113-124.
unnamed Ornithuromorpha (Forster and O'Connor, 2000; described by O'Connor
and Forster, 2010)
Middle Maastrichtian, Late Cretaceous
Anembalemba Member of Maevarano Formation, Madagascar
Material- (FMNH PA 748) distal humerus (O'Connor and Forster, 2010)
(UA 9601) synsacrum (25 mm) (Forster and O'Connor, 2000; described by O'Connor
and Forster, 2010)
(UA 9607) distal humerus (O'Connor and Forster, 2010)
Comments- The synsacrum UA 9601 was reported by Forster and
O'Connor (2000), then by O'Connor and Forster (2009) as an ornithurine
sensu Gauthier and de Queiroz. It was later described by O'Connor and
Forster (2010) as an ornithurine sensu Gauthier and de Queiroz based on having ten vertebrae, while
the distal humeri were described as ornithurines sensu Gauthier and de Queirozbased on "a
well-defined dorsal supracondylar tubercle, an incipient
scapulotricipital sulcus, and the assortment of small fossae on the
distal end (e.g., fossae associated with the ventral epicondyle)."
References- Forster and O'Connor, 2000. The avifauna of the Upper Cretaceous
Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 20(3),
41A-42A.
O'Connor and Forster, 2009. The Late Cretaceous (Maastrichtian) avifauna from
the Maevarano Formation, Northwestern Madagascar: Recent discoveries and new
insights related to avian anatomical diversification. Journal of Vertebrate
Paleontology. 29(3), 157A.
O'Connor and Forster, 2010. A Late Cretaceous (Maastrichtian) avifauna from
the Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 30(4),
1178-1201.
unnamed Ornithuromorpha (Agnolin and Martinelli, 2009)
Campanian-Maastrichtian, Late Cretaceous
Los Alamitos Formation, Rio Negro, Argentina
Material- (MACN PV RN 1111) distal tibiotarsus
(MACN PV RN 1112) distal tibiotarsus
(MACN PV RN 1113) distal tibiotarsus
Comments- These have a non-bridged extensor groove.
Reference- Agnolin and Martinelli, 2009. Fossil birds from the Late Cretaceous
Los Alamitos Formation, R�o Negro province, Argentina. Journal of South
American Earth Sciences. 27, 42-49.
Songlingornithidae Hou, 1997
Definition- (Songlingornis linghensis <- Chaoyangia beishanensis,
Passer domesticus) (Martyniuk, 2012)
= Yixianorniformes Zhang and Zhou, 2006
= Yixianornithidae Zhang and Zhou, 2006
Other diagnoses- Clarke et al. (2006) found four characters to unambiguously
diagnose this clade in a version including Yanornis. Yanornis has not been shown to lack completely heterocoelous cervicals. A posteromedial sternal process
joining distally to the posteromedian process to form a fenestra is also seen in Piscivoravis, Iteravis and Gansus. A procoracoid process is now known in all basal euornithines except Patagopteryx and Apsaravis.
The lack of a medially concave coracoid surface (where the supracoracoid foramen
exits if it is present) is more parsimoniously primitive to euornithines,
as it is present in Bellulornis and Arcaheornithura, while the concavity
in Apsaravis is considered a reversal.
Zhou and Zhang's (2006) diagnosis for Yixianornis' eponymous family and
order was the same as their 2001 diagnosis for the genus. Most of those characters
are apomorphic for Yixianornis or otherwise problematic (see Yixianornis
diagnosis), except the femoro-tarsometatarsal ratio of ~150-170%, which
is also present in e.g. Jianchangornis (162-169%), Archaeorhynchus
(164-185%) and Piscivoravis (157%).
Comments- Hou (1997) originally named Songlingornithidae for Songlingornis
within the Chaoyangiformes, while Zhou and Zhang (2001) later placed Yixianornis in
Chaoyangornithiformes. Zhou and Zhang (2006) created Yixianornithidae and Yixianornithiformes
for Yixianornis, and placed Songlingornis in the Chaoyangornithiformes
and "Chaoyangornithidae". Clarke et al. (2002) were the first to suggest
placing these taxa and Yanornis into a single clade at their SVP talk, though this was
not published until 2006. You et al. (2006) independently coded Yanornis
and Yixianornis and found the taxa to form a monophyletic clade in some
of their most parsimonious trees, though in others Yanornis was more
derived and sister to Apsaravis. The monophyletic clade of Yanornis,
Yixianornis and/or Songlingornis has been called Songlingornithidae
by many recent authors, but here Yanornis is recovered as further from Aves than Yixianornis and Songlingornis based on Hartman et al.'s maniraptoromorph matrix.
References- Hou, 1997. Mesozoic birds of China. Taiwan Provincial Feng
Huang Ku Bird Park. Taiwan: Nan Tou. 228 pp.
Zhou and Zhang, 2001. [Two new genera of ornithurine birds from the Early Cretaceous
of Liaoxi involved in the origin of modern birds.] Kexue Tongbao. 46(5), 371-377.
Clarke, Zhou and Zhang, 2002. An ornithurine from the Early Cretaceous of China.
Journal of Vertebrate Paleontology. 22(3), 45A.
Clarke, Zhou and Zhang, 2006. Insight into the evolution of avian flight from
a new clade of Early Cretaceous ornithurines from China and the morphology of
Yixianornis grabaui. Journal of Anatomy. 208, 287-308.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
Zhou and Zhang, 2006. Mesozoic birds of China- A synoptic review. Vertebrata
PalAsiatica. 44(1), 60-98.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Yixianornis Zhou and Zhang, 2001
Y. grabaui Zhou and Zhang, 2001
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Holotype- (IVPP V12631) (~215 mm, 320 g) skull (~39 mm), mandibles, sclerotic
ring, atlas, axis, third cervical vertebra, fourth cervical vertebra, fifth
cervical vertebra, sixth cervical vertebra, seventh cervical vertebra, eighth
cervical vertebra, ninth cervical vertebra, tenth cervical vertebra, eleventh
cervical vertebra, twelfth cervical vertebra, ten dorsal vertebrae (5.8 mm),
dorsal ribs, uncinate processes, fifteen rows of gastralia, synsacrum (25 mm),
five caudal vertebrae, pygostyle (7.92 mm), scapulae (48.1 mm), coracoids (23.3 mm), furcula,
sternum (43.1 mm), sternal ribs, humeri (49.3 mm), radii (48 mm), ulnae (50.3
mm), scapholunare, pisiforms, carpometacarpi (mc I 5 mm, mc II 21 mm, mc III 21 mm),
phalanges I-1 (10.8 mm), manual unguals I (6.1 mm), phalanges II-1 (12.5 mm),
phalanges II-2 (12.3 mm), manual unguals II (5 mm), phalanges III-1 (6 mm),
ilia (23.5 mm), pubes (~42.2 mm), ischium (~20.5 mm), femora (41 mm), tibiotarsi
(52.8 mm), fibula (~15 mm), metatarsal I (4 mm), phalanges I-1 (7.8 mm), pedal
unguals I (5 mm), tarsometatarsi (27.30 mm), phalanges II-1 (11.3 mm), phalanges
II-2 (9.4 mm), pedal unguals II (6 mm), phalanges III-1 (11.5 mm), phalanges
III-2 (8.7 mm), phalanges III-3 (8.3 mm), pedal unguals III (6 mm), phalanges
IV-1 (7 mm), phalanges IV-2 (5.8 mm), phalanges IV-3 (5.6 mm), phalanges IV-4
(6.2 mm), pedal unguals IV (5 mm), body feathers, eleven remiges (to 67 mm),
eight retrices (~75-~92 mm)
Diagnosis- (after Zhou and Zhang, 2001) snout anterior to frontal margin
of orbit 41% of skull length; metacarpal III 32% the width of metacarpal II
(unknown in Songlingornis); pubic symphysis ~16% the length of pubis
(unknown in Songlingornis); ratio of pedal digit III to tarsometatarsus
length 128% (unknown in Songlingornis).
Other diagnoses- Zhou and Zhang (2001) included a few other characters
in their diagnosis. The short snout was expressed as a ratio of skull length
to width (stated to be 150%, but in actuality 175% as preserved). However, the
width is exaggerated by crushing the mandibles and jugals laterally, and the
true ratio based on the postorbital processes is 235%. This makes it probably
comparable to Hongshanornis, and Songlingornis is probably also
short-snouted based on its dentary proportions, though difficult to quantify
thanks to a lack of posterior skull material and good illustration. Clarke et
al. (2006) use another measure of this feature, namely dentary length, which
they state is shorter than in Songlingornis. One measure which can be
compared in both Yixianornis and Hongshanornis is length anterior
to the frontal margin of the orbit, which is shorter in Yixianornis (41%
vs. 51%). It could be assumed Songlingornis' apparently longer dentary
indicates it had a larger ratio. "Postcranial long bones slender"
is unspecific and unquantified, but seems to be even more true of Hongshanornis
and Gansus. Most euornithines have protruding elliptical humeral heads.
While Zhou and Zhang use a pubic symphysis length of 20% pubic length in their
diagnosis, their measurement table indicates a ratio of 26%, and Clarke et al.'s
measurements indicate a smaller ratio of 16% (based on a pubis estimated to
be 7 mm longer). While the proximal pubis is hidden by the femur, I find Clarke
et al.'s estimate more likely based on the general length of basal bird pubic
peduncles. The femoro-tarsometatarsal ratio (stated to be 160%, but actually
152%) is overlapped by Yanornis (149-170%).
Clarke et al. state the xiphoid process (just posterior to the costal margin)
of the sternum has a greater extent along the sternal margin than in Yanornis
or Songlingornis, but that of Hongshanornis and Gansus
are longer (Songlingornis' seems to be also, at least in Hou's illustration).
They also stated the interclavicular angle was longer than in Yanornis
or Songlingornis, but this is also true in Hongshanornis, Archaeorhynchus
and Gansus.
Comments- The holotype is misidentified as IVPP V13631 in Clarke et al.'s
(2006) redescription. Their measurement of 12.5 mm for pedal phalanx IV-1 is
also in error.
References- Zhou and Zhang, 2001. [Two new genera of ornithurine birds
from the Early Cretaceous of Liaoxi involved in the origin of modern birds.]
Kexue Tongbao. 46(5), 371-377.
Zhou and Zhang, 2001. Two new ornithurine birds from the Early Cretaceous of
western Liaoning, China. Chinese Science Bulletin. 46(1), 1-7.
Clarke, Zhou and Zhang, 2002. An ornithurine from the Early Cretaceous of China.
Journal of Vertebrate Paleontology. 22(3), 45A.
Clarke, Zhou and Zhang, 2006. Insight into the evolution of avian flight from
a new clade of Early Cretaceous ornithurines from China and the morphology of
Yixianornis grabaui. Journal of Anatomy. 208, 287-308.
Wang, O'Connor, Pan and Zhou, 2017. A bizarre Early Cretaceous
enantiornithine bird with unique crural feathers and an ornithuromorph
plough-shaped pygostyle. Nature Communications. 8:14141.
Bailleul, Li, O'Connor and Zhou, 2019. Origin of the avian predentary
and evidence of a unique form of cranial kinesis in Cretaceous
ornithuromorphs. Proceedings of the National Academy of Sciences.
116(49), 24696-24706.
Songlingornis Hou, 1997
S. linghensis Hou, 1997
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Holotype- (IVPP V10913) (~190 mm) premaxilla, maxilla, nasals, quadrate,
mandibles (25.5 mm), cervical vertebrae, several dorsal vertebrae, two dorsal
ribs (31 mm), two dorsal rib fragments, scapula, coracoids (22.5 mm), furcula,
sternum (35 mm), proximal radius, distal ulnae, carpometacarpus (25 mm), proximal
femur, partial tarsometatarsus?
Diagnosis- (after Hou, 1997) dorsal edge of scapula almost straight.
(after Clarke et al., 2006) width of distal expansion of posterolateral sternal
process 28% of sternal length.
Other diagnoses- Hou (1997) included numerous characters in his diagnosis,
but many are vague (mandible slender and elongate; ribs slender and elongate;
well developed coracoid head; relatively well developed carpometacarpus; well
developed femoral head) or primitive (dorsal vertebrae not heterocoelous; concave
coracoid facet for scapula; procoracoid process present; supracoracoid foramen
present; distal fossa on posterior coracoid; hypocleidium absent; elongate and
broad sternum; deep coracoid grooves on sternum; distinct sternal carina). Others
are found in other songlingornithids (teeth closely packed; more than nine dentary
teeth; large anterolateral sternal process; well developed xiphoid sternal process;
posterolateral sternal process with expanded tip; posterolateral sternal process
extends posteriorly far beyond posteromedian process; posteromedial sternal
process joins distally to posteromedian process forming fenestra).While Hou
says the sternal rostrum ("manubrium") is well developed in the diagnosis,
he later states it is damaged and cannot be described.
Zhou and Hou (2002) diagnose Chaoyangia partly using characters from
Songlingornis. Most of the characters are repeated from Hou's earlier
Songlingornis diagnosis. The remainder are plesiomorphic (premaxillary and dentary
teeth present; U-shaped furcula; sternal keel extends along full length of sternum;
short posterolateral sternal process).
Comments- This specimen was collected in 1992 and mentioned by Zhou (1995)
as being probably referrable to Chaoyangia. Hou et al. (1995) say it
is at least referrable to Euornithes (their Ornithurae), and later (1996)
refer it to Chaoyangia due to the similar size and rarity of euornithine
birds in the deposits. Hou (1997) described it as the new taxon Songlingornis
linghensis, while Zhou and Hou (2002) referred it to Chaoyangia but
did indicate it had also been used as the holotype of Songlingornis.
The holotypes of both specimens preserve few elements in common (though not
none, as claimed by Clarke and Norell, 2001)- several dorsal vertebrae, dorsal
ribs and proximal femur. The dorsals are alike in being non-heterocoelous, but
this is similar to all non-hesperornithine, non-avian birds. Both femora are
described as having proximally projecting trochanteric crests, shallow trochanteric
fossae and large heads. These features are comparable to many basal birds including
Confuciusornis and Vorona. The only point of difference in their
descriptions in that Chaoyangia is said to have a "basically absent"
neck, while Songlingornis has a "relatively well developed neck."
Yet Chaoyangia's proximal femur has a near identical shape to Patagopteryx's,
which has a neck, and Songlingornis' illustration is too schematic for
proper comparison. Thus the taxa cannot be distinguished, but also share no
synapomorphies that would allow them to be synonymized.
Songlingornis was originally described as a basal euornithine (Ornithurae
of Hou) by Hou (1997), placed on his phylogram more derived than Liaoningornis
but less than Gansus and Ornithurae sensu Chiappe. Clarke (2002) was
the first author to include the taxon in a cladistic analysis, finding it to
be a carinate in an unresolved polytomy with Ichthyornis and more derived
birds. More recently, Clarke et al. included Yanornis and Yixianornis
in their matrix and found Songlingornis to clade with these taxa in a
group more derived than Patagopteryx, but less than Apsaravis
and Ornithurae. This was first announced at their SVP 2002 talk,
but only published in 2006.
References- Hou, Zhou, Gu and Sun, 1995. Introduction to Mesozoic birds
from Liaoning, China. Vertebrata PalAsiatica. 33(4), 261-271.
Zhou, 1995. New understanding of the evolution of the limb and girdle elements
in early birds - evidences from Chinese fossils. In Sun and Wang (eds.). Sixth
Symposium on Mesozoic Terrestrial Ecosystems and Biota. Short papers, 209-214.
Hou, Martin, Zhou and Feduccia, 1996. Early adaptive radiation of birds: evidence
from fossils from northeastern China. Science. 274, 1164-1167.
Hou, 1997. Mesozoic birds of China. Taiwan Provincial Feng Huang Ku Bird Park.
Taiwan: Nan Tou. 228 pp.
Clarke and Norell, 2001. Fossils and avian evolution. Nature. 414, 508.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, Zhou and Zhang, 2002. An ornithurine from the Early Cretaceous of China.
Journal of Vertebrate Paleontology. 22(3), 45A.
Zhou and Hou, 2002. The Discovery and Study of Mesozoic Birds in China. in Chiappe
and Witmer, (eds.). Mesozoic Birds- Above the Heads of Dinosaurs. University
of California Press, Berkeley, Los Angeles, London. 160-183.
Clarke, Zhou and Zhang, 2006. Insight into the evolution of avian flight from
a new clade of Early Cretaceous ornithurines from China and the morphology of
Yixianornis grabaui. Journal of Anatomy. 208, 287-308.
Ambiortiformes Kurochkin, 1982
Definition- (Ambiortus dementjevi <- Passer domesticus)
(Martyniuk, 2012)
= Ambiortidae Kurochkin, 1982
= Gansuiformes Hou and Liu, 1984
Definition- (Gansus yumenensis <- Passer domesticus, Hesperornis
regalis, Ichthyornis anceps, Enantiornis leali) (Martyniuk, 2012)
= Gansuidae Hou and Liu, 1984
= Gansuiornithiformes Zhou and Zhang, 2006
= "Gansuiornithidae" Zhou and Zhang, 2006
= Ambiortes Zelenkov in Zelenkov and Kurochkin, 2015
Comments- Kurochkin (1982) established the monotypic Ambiortiformes and
Ambiortidae, but later (1999) assigned Otogornis to the Ambiortiformes
as well, and even later (2000) to the Ambiortidae. This was based on several
problematic characters. The acrocoracoid of Otogornis is not noticably
thicker than Enantiornis, which also shares the "three edged"
morphology. The proximal tip of Otogornis' acrocoracoid is not necessarily
acute (compare medial view of left coracoid to other figures). The glenoid on
the scapula is no wider in Ambiortus than Enantiornis and appears
concave in Hou's original illustration, but is flat in some enantiornithines
(e.g. Gobipteryx) anyway. Otogornis' humeral head is no more ventrally
placed than Sinornis', and is not smaller or shorter. Nor is it oval,
having a proximally concave margin as in enantiornithines. Finally, the long
and thin manual phalanx II-2 is symplesiomorphic, being found in most basal
birds. Otogornis
seems to be an enantiornithine instead. Martyniuk (2012) later defined
the clade. Ambiortes was created by Zelenkov in a book chapter by
Zelenkov and Kurochkin (2015) to only include Ambiortiformes.
Zhou and Zhang (2006) listed Gansuiornithiformes and "Gansuiornithidae",
which are incorrectly formed as there is no genus "Gansuiornis". Furthermore,
"Gansuiornithidae" is a nomen nudum since it was not defined or diagnosed
(ICZN Article 13.1.1).
References- Kurochkin, 1982. Novyy otryad ptits iz nizhnego mela Mongolii.
Doklandy Akademii Nauk SSSR. 262(2), 452-455.
Hou and Liu, 1984. A new fossil bird from Lower Cretaceous
of Gansu and early evolution of birds. Scientia Sinica. 27, 1296-1302.
Kurochkin, 1999. The relationships of the Early Cretaceous Ambiortus
and Otogornis (Aves: Ambiortiformes). in Olson (ed). Avian Paleontology
at the Close of the 20th Century: Proceedings of the 4th International Meeting
of the Society of Avian Paleontology and Evolution. Smithsonian Contributions
to Paleobiology. 89, 275-284.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia.
533-559.
Zhou and Zhang, 2006. Mesozoic birds of China- A synoptic review. Vertebrata
PalAsiatica. 44(1), 60-98.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Zelenkov and Kurochkin, 2015. Class Aves. In Kurochkin, Lopatin and
Zelenkov (eds.). Fossil vertebrates of Russia and adjacent countries.
Part 3. Fossil Reptiles and Birds. GEOS. 86-290.
Yumenornis Wang, O'Connor, Li
and You, 2013
Y. huangi Wang, O'Connor, Li and You, 2013
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Holotype- (GSGM-06-CM-013) scapula, coracoid, partial furcula, partial sternum,
sternal ribs, humerus (49.9 mm), radius (49.7 mm), ulna (52.9 mm), pisiform, carpometacarpus
(27 mm), phalanx I-1 (10.9 mm), manual ungual I (5.4 mm), phalanx II-1 (12.1
mm), phalanx II-2 (11.5 mm), manual ungual II (4.2 mm), phalanx III-1 (6.7 mm)
Diagnosis- (after Wang et al., 2013) sternum with angular rostral margin
(~90�), lateral (zyphoid) processes, and robust, distally expanded lateral
trabeculae; radius with deep distal fossa; ratio of length of manus relative
to humerus 1.1.
Comments- Wang et al. (2013b) entered this into O'Connor's matrix and
found it to be a basal euornithine in large polytomy with taxa less derived
than Ichthyornis but more derived than Patagopteryx. The flexor
tuber on manual phalanx III-1 suggests Yumenornis is as close to Aves
as Iteravis.
References- Wang, O'Connor, Li and You, 2013a. A new ornithuromorph bird
from the Early Cretaceous Changma Basin of Gansu Province, Northwestern China.
Journal of Vertebrate Paleontology. Program and Abstracts 2013, 234-235.
Wang, O'Connor, Li and You, 2013b. Previously unrecognized ornithuromorph bird
diversity in the Early Cretaceous Changma Basin, Gansu Province, Northwestern
China. PLoS ONE. 8(10), e77693.
Juehuaornis Wang, Wang and Hu,
2015
?= Changzuiornis Huang, Wang, Hu, Liu, Peteya and Clarke, 2016
= Dingavis O'Connor, Wang and Hu, 2016
J. zhangi Wang, Wang and Hu, 2015
?= Changzuiornis ahgmi Huang, Wang, Hu, Liu, Peteya and Clarke, 2016
= Dingavis longimaxilla O'Connor, Wang and Hu, 2016
Early Albian, Early Cretaceous
Sihedang, Jiufotang Formation, Liaoning, China
Holotype- (SJG 00001) skull (63.3 mm), mandible, cervical vertebrae,
cervical ribs, about nine dorsal vertebrae, dorsal ribs, synsacrum, caudal vertebrae,
pygostyle, scapulae (41 mm), coracoid, furcula, sternum, humeri (46.7, 45.5
mm), radii, ulnae (55.5 mm), scapholunare, carpometacarpi (31.1 mm), phalanx I-1
(11 mm), manual ungual I (3.4 mm), phalanges II-1 (15.5 mm), phalanges II-2
(12.2 mm), manual unguals II, phalanges III-1 (6.8 mm), phalanx III-2, ilium,
pubes (~38.9 mm), ischium, femur (~33.3 mm), tibiotarsi (55.6 mm), fibula, metatarsal
I, phalanges I-1, pedal ungual I, tarsometarsi (38.7 mm), phalanges II-1, phalanges
II-2, pedal unguals II, phalanges III-1, phalanges III-2, phalanges III-3, pedal
unguals III, phalanges IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4,
pedal unguals IV, body feathers, remiges
Referred- (AGB5840; holotype of Changzuiornis ahgmi) (adult) skull
(65 mm), scleral ring, mandibles, hyoids, basihyal, eleven or twelve cervical
vertebrae (~7.1 mm) with fused ribs, about ten dorsal vertebrae, few dorsal
ribs, gastralia, sacrum (~33 mm), several caudal vertebrae, pygostyle (9.1 mm),
scapula (46.4 mm), coracoid (23.8 mm), furcula, humeri (50.4, 50.1 mm), radii
(50.6, 48.6 mm), ulnae (52, 53.6 mm), scapholunares, pisiforms, carpometacarpi (30.1,
31.3 mm; mcI 5.4, 5.1 mm), phalanx I-1 (11.7 mm), manual ungual I (5.4 mm),
phalanges II-1 (12.9, 11.6 mm), phalanges II-2 (14.4, 12.6 mm), partial manual
ungual II (3.6 mm), fragmentary ilium (30.4 mm), pubes (34.3 mm), ischium (38.4
mm), incomplete femur (29.4 mm), tibiotarsi (53.7, 54 mm excluding cnemial
crest), phalanx I-1 (7.2 mm), pedal ungual I, tarsometatarsi (36, 36.1 mm),
phalanges II-1 (9.5, 8.7 mm), phalanges II-2 (one proximal; 10.7, 9.9 mm), pedal
ungual II, phalanges III-1 (8.9, 7.1 mm), phalanges III-2 (8.4, 6.8 mm), phalanges
III-3 (~5.9, 6.3 mm), pedal ungual III, phalanges IV-1 (7.7, 7.4 mm), phalanges
IV-2 (7.2, 7.1 mm), phalanges IV-3 (5.4, 6 mm), phalanges IV-4 (5.4, 6.5 mm),
pedal unguals IV, body feathers, remiges, ~five gastroliths (~30 mm) (Wang et
al., 2015b; described by Huang et al., 2016)
(IVPP V20284; holotype of Dingavis longimaxilla) (adult) skull (58.6
mm), mandible, eight cervical vertebrae, dorsal fragments, partial dorsal ribs,
gastralia, synsacrum (28.2 mm), four caudal vertebrae, pygostyle (7.8 mm), scapulae
(38.4 mm), proximal coracoid, fragmentary sternum, humeri (48.9, ~51 mm), radii,
ulnae (~44.9, ~52 mm), scapholunare, proximal carpal, carpometacarpi (30.4, 29.9
mm; mcI 4.1 mm), phalanges I-1 (12.4, 12.5 mm), manual unguals I (4.9, 5 mm),
phalanges II-1 (14, 13.2 mm), phalanges II-2 (13.2, 13.2 mm), manual unguals
II (3.9, 4 mm), phalanges III-1 (6.6, 7.9 mm), ilia, pubes (42.7 mm), ischia,
femora (one partial; 36.1 mm) tibiotarsi (55.6, 55.4 mm), fibula, metatarsals
I, phalanges I-1, pedal unguals I, tarsometatarsi (37.9, 40.6 mm), phalanges
II-1, phalanges II-2, pedal unguals II, phalanges III-1, phalanges III-2, phalanges
III-3, pedal unguals III, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanges
IV-4, pedal unguals IV, ~40 gastroliths (O'Connor, Wang and Hu, 2016)
Diagnosis- (after Wang et al., 2015a) anterior of mandible straight;
teeth only present in maxilla and dentary.
(after O'Connor et al., 2016; for Dingavis) rostrum forms 63-65% of skull
length; jugal process of lacrimal posterolaterally excavated; length of carpometacarpus
+ major digit exceeds humeral length by 25% (118-126% in Dingavis' type,
~135% in Juehuaornis' type, 118-~121% in Changzuiornis' type);
short metacarpal I (13.7% of metacarpal II) (12-14% in Dingavis' type,
~14% in Juehuaornis' type, 16-18% in Changzuiornis' type); tarsometatarsus
with small but sharp medial and lateral plantar crests, plantar surface of metatarsus
not excavated; metatarsal II much shorter than metatarsal IV; metatarsal II
and IV trochlea plantarly displaced; metatarsal II trochlea strongly angled
craniomedially.
Other diagnoses- Wang et al. (2015a) listed a longer snout length (~70%)
as diagnostic of Juehuaornis. They claim the premaxilla is hooked, but
this isn't apparent from the photo. The Dingavis holotype has a disarticulated
predentary which resembles a frigatebird-style hook at first glance, so this
provides a possible explanation for the Juehuaornis holotype. Wang et
al. also list forelimb and hindlimb similar in length as diagnostic, which is
104% in Juehuaornis and a similar 96-101% in Dingavis' type. However,
Changzuiornis' type has a longer forelimb (111-112%).
O'Connor et al. (2016) claimed Dingavis lacks teeth, but the material
is very poorly preserved, so that small teeth may not be visible (as in the
Hongshanornis type).
Huang et al. (2016) distinguished Changzuiornis and Juehuaornis
from Dingavis by their longer skulls (221% and 190% of femoral length
vs. 162%), but these form a gradation that matches specimen size. Similarly,
they distinguished Changzuiornis by its longer scapula (158% of femoral
length vs. 123% in Juehuaornis and 101-107% in Dingavis), but
this also matches specimen size. One difference noted by Huang et al. that doesn't
match specimen size is the ratio between manual phalanges II-1 and II-2, which
is 109-112% in Changzuiornis, but 79% in Juehuaornis and 94-100%
in Dingavis.
Comments- While O'Connor et al. (2016) assigned Dingavis to the
Yixian Formation, it was found in Sihedang, which is here viewed as belonging
to the Jiufotang Formation (see Iteravis entry). Chen (DML 2016) proposed
Dingavis is a junior synonym of Juehuaornis. As he noted, they
have very similar proportions and each has the others' diagnostic characters
when known, with the exceptions of the supposed hooked bill of Juehuaornis,
and toothlessness of Dingavis as described above under 'Other diagnoses'.
The only other significant difference observed by Chen is that Dingavis
supposedly lacks manual phalanx III-2, but as he says, this is very small in
Juehuaornis and so easily lost in the poorly preserved Dingavis
holotype. Wang et al. (2015b) first noted another Jiufotang longirostrine euornithine
which was formally described by Huang et al. (2016) as Changzuiornis.
Huang et al. considered the possibility their new taxon was synonymous with
the other Sihedang longirostrine birds, stating "while if new data shows
that Xinghaiornis, Juehuaornis and Dingavis form a clade
that constitutes the same genus, the genus name Juehuaornis would have
priority for Dingavis longimaxilla and Changzuiornis ahgmi."
The few differences listed are all proportional, and it's notable almost all
proportional differences between the three holotypes covary with size, with
the generally intermediate-sized Juehuaornis the usual intermediary proportion-wise
too. This suggests the possibility of a growth series, which is provisionally
accepted here.
The holotype of Juehuaornis was briefly described in Chinese and only
illustrated as low resolution photos of part and counterpart. It has yet to
be included in a phylogenetic analysis, but was classified by Wang et al. (2015a)
as an ornuthuromorph. O'Connor et al. recovered Dingavis as more derived
than Archaeorhynchus but less than hongshanornithids and songlingornithids
plus avians using O'Connor's matrix. Huang et al. (2016) recovered Changzuiornis
as more derived than hongshanornithids and songlingornithids, but less than
Iteravis, Gansus and taxa closer to Aves, using a version of Clarke's
matrix.
References- Wang, Clarke and Huang, 2015b. Ornithurine bird from the
Early Cretaceous of China provide new evidence for the timing and pattern of
the evolution of avian skull. Journal of Vertebrate Paleontology. Program and
Abstracts 2015, 233.
Wang, Wang and Hu, 2015a. Discovery of a new ornithuromorph genus, Juehuaornis
gen. nov. from Lower Cretaceous of western Liaoning, China.
Global Geology. 34(1), 7-11.
Chen, DML 2016. https://web.archive.org/web/20160901192554/http://dml.cmnh.org/2016Jan/msg00050.html
Huang, Wang, Hu, Liu, Peteya and Clarke, 2016. A new ornithurine from the Early
Cretaceous of China sheds light on the evolution of early ecological and cranial
diversity in birds. PeerJ. 4:e1765.
O'Connor, Wang and Hu, 2016. A new ornithuromorph (Aves) with an elongate rostrum
from the Jehol Biota, and the early evolution of rostralization in birds. Journal
of Systematic Palaeontology. 14(11), 939-948.
Iteravis Zhou, O'Connor and
Wang, 2014
I. zheni (Liu, Chiappe, Zhang, Bell, Meng, Ji and Wang, 2014)
new combination
= Gansus zheni Liu, Chiappe, Zhang, Bell, Meng, Ji and Wang, 2014
= Iteravis huchzermeyeri Zhou, O'Connor and Wang, 2014
Early Albian, Early Cretaceous
Sihedang, Jiufotang Formation, Liaoning, China
Holotype- (BMNHC Ph 1342) (adult) skull (53.3 mm), mandibles, hyoid, eleven
cervical vertebrae, few dorsal vertebrae, several dorsal ribs, gastralia, incomplete
sacrum, few caudal vertebrae, pygostyle, scapulae (40.4 mm), coracoids (20.7,
20.7 mm), furcula, sternum, sternal ribs, humeri (54.6, 53.4 mm), radii (54.9,
54.3 mm), ulnae (56.1, 55.1 mm), scapholunares, pisiforms, carpometacarpi (27.1, 25.6
mm), phalanges I-1 (~11 mm), manual unguals I (~6 mm), phalanges II-1 (~10,
~12 mm), phalanges II-2 (~12, ~13 mm), partial manual ungual II, phalanges III-1
(~6, ~8 mm), ilia, pubes, ischia, femora (36.4 mm), tibiotarsi (64.4, 66.1 mm),
proximal fibulae, metatarsals I, phalanges I-1 (8.4, 8.2 mm), pedal unguals
I (3.9, 4.2 mm), tarsometatarsi (37.9, 38.1 mm), phalanges II-1 (15, 14.9 mm),
phalanges II-2 (13.5, 14.4 mm), pedal unguals II (4.6, 5.1 mm), phalanges III-1
(15.5, 14.3 mm), phalanges III-2 (11, 11 mm), phalanges III-3 (10.2, 9.1 mm),
pedal unguals III (4.1, 4.8 mm), phalanges IV-1, (10.6, 11 mm), phalanges IV-2
(9.1, 8.7 mm), phalanges IV-3 (8.5, 8.5 mm), phalanges IV-4 (8.2, 8.3 mm), pedal
unguals IV (3.5, 3.5 mm), remiges, body feathers, gastroliths
Paratypes- (BMNHC Ph 1318) (adult) skull (45.4 mm), mandibles, hyoid,
ten cervical vertebrae, few dorsal vertebrae, several dorsal ribs, incomplete
sacrum, scapular fragments, coracoids (one incomplete; 22.9, 21.2 mm), furcula,
incomplete sternum, sternal ribs, incomplete humeri (53.6, 52.3 mm), radii (one
partial; 50.2 mm), ulnae (one partial; 54.1 mm), fragmented proximal carpals,
partial carpometacarpi (21.6 mm), phalanges I-1, manual ungual I, phalanges
II-1, phalanges II-2, manual ungual II, phalanges III-1, partial ilia, pubes,
ischium, incomplete femora (34.5, 34.6 mm), tibiotarsi (63.8, 65.4 mm), fibulae,
metatarsi I, phalanges I-1 (7.7, 7.5 mm), pedal unguals I (4.1, 4.6 mm), tarsometatarsi
(36.9, 36.5 mm), phalanges II-1 (13.7, 12.9 mm), phalanges II-2 (12, 12.7 mm),
pedal unguals II (4.6, 4.5 mm), phalanges III-1 (13.5, 13.8 mm), phalanges III-2
(10.4, 10.4 mm), phalanges III-3 (8.8, 8.7 mm), pedal unguals III (4.7, 4.2
mm), phalanges IV-1 (10.4, 9.8 mm), phalanges IV-2 (8.5, 8.3 mm), phalanges
IV-3 (8, 8.3 mm), phalanges IV-4 (7.9, 7.1 mm), pedal unguals IV (3.7, 3.9 mm),
remiges, gastroliths (Liu et al., 2014)
(BMNHC Ph 1394) complete specimen including sternum and gastroliths (Liu et al.,
2014)
Referred- (IVPP V18958; holotype of Iteravis huchzermeyeri) (old
subadult) skull (46 mm), sclerotic plates, mandibles, hyoid, ten cervical vertebrae
fused with ribs, nine dorsal vertebrae, dorsal ribs, uncinate process, gastralia,
synsacrum, five or six caudal vertebrae, chevrons, pygostyle (6.93 mm), scapulae (one
incomplete; 35 mm), coracoids (21 mm), furcula, incomplete sternum, three sternal
ribs, humeri (52 mm), radii, ulnae (53 mm), scapholunare, pisiform, carpometacarpi
(mcI 4, mcII 22, mcIII 18 mm), phalanges I-1 (9.5 mm), manual ungual I (4 mm),
phalanges II-1 (11.5 mm), phalanges II-2 (11 mm), manual ungual II (3 mm), phalanx
III-1 (6 mm), fused pelves (pubis 41 mm), femora (35 mm), tibiotarsi (59 mm),
fibula, metatarsals I, phalanx I-1 (8 mm), pedal ungual I (3 mm), tarsometatarsi
(31.50 mm), phalanges II-1, phalanges II-2 (11.5 mm), pedal unguals II (4.5 mm),
phalanges III-1 (12 mm), phalanges III-2 (10 mm), phalanges III-3 (8 mm), pedal
ungual III (4 mm), phalanges IV-1 (10 mm), phalanges IV-2 (8 mm), phalanges
IV-3 (8 mm), phalanges IV-4 (7 mm), pedal unguals IV (3.5 mm), bulbi retricium,
skin, remiges, retrices, body feathers, six gastroliths (4-5 mm) (Zhou, O'Connor
and Wang, 2014)
most of twenty specimens including tarsometatarsi (32-36 mm) (Zhou, O'Connor
and Wang, 2014)
Diagnosis- (after Zhou et al., 2014) ischium with concave ventral margin
and weak mid dorsal process (also in Piscivoravis, Yanornis and
Gansus).
(modified after Liu et al., 2014) pedal digit IV subequal to 10% longer than
III, excluding unguals (also in Schizooura and some Gansus); pedal
unguals III and IV plesiomorphically lacking prominent pendant flexor tubercle
of Gansus.
Other diagnoses- Zhou et al. (2014) listed a number of characters which
are actually symplesiomorphic for Gansus-grade euornithines- elongate
premaxilla; toothless premaxilla; rostrum 50% of skull length; ectethmoid bone
lining anterior half of orbit; flexor tubercle on posterior margin of manual
phalanx III-1; pubes with posteriorly expanded distal boot. They also listed
"maxilla with numerous teeth", but only "several" teeth
are claimed to be present and only a couple are visible, so this is plesiomorphic
for euornithines too.
Liu et al. (2014) also diagnosed Gansus zheni using several characters
compared to G. yumenensis which are problematic. The broader interclavicular
angle (~45-~53 degrees, not 60 as Liu et al. state) is found in several other
basal euornithines, and almost all basal euornithines have U-shaped furculae.
Compared to Gansus yumenensis, zheni/Iteravis actually has a longer
cnemial crest (8-15% of tibiotarsal length vs. 4%), a shorter manual digit II
(excluding ungual, 86-102% of metacarpal II length vs. 81-83%; same ratio as
several other basal euornithines), and overlapping pedal digit III / tarsometatarsal
ratios (excluding ungual, 89-97% vs. 74-101%; same ratio as several other basal euornithines), contra Liu et al..
Comments- Zhou et al. (2014) believed the Sihedang locality which these
specimens derive from to be in the Yixian Formation, whereas Liu et al. (2014)
believed it to be in the overlying Jiufotang Formation. Zhou et al. cite undescribed
turtles and a caudipterid as being found in the locality, though both are known
from both formations (as Similicaudipteryx has been referred to Caudipteridae,
though it is near certainly more basal). The pterosaurs Guidraco and
Ikrandraco are also from Sihedang however, referred to the Jiufotang
Formation in both descriptions. As Ikrandraco is also known from another
Jiufotang locality (Lamadong), the Jiufotang Formation is favored here as the
stratigraphic placement of Iteravis.
Zhou et al. (2014) found Iteravis to be more derived than hongshanornithids
and songlingornithids, but outside hesperornithoids and Aves. Liu et al. (2014)
found it to be sister to Gansus yumenensis, so they named it as
a new species of that genus. The position used here, just basal to Gansus
and more derived birds, is based on the partly corrected matrix of Liu et al.
as described below and coincidentally matches the first most parsimonious tree
found by Zhou et al. before they found more trees one step shorter.
Note the main skeletal figures in Liu et al. (2014; figures 1 and 2) have the
specimen numbers switched, so figure 1 says its of BMNHC Ph 1342 but is actually
of BMNHC Ph 1318, and the reverse is true of figure 2. Also, Zhou et al. claim
they used the data matrix of O'Connor et al.'s 2011 redescription of Rapaxavis,
but that paper has no phylogenetic analysis. It seems they actually used the
matrix of O'Connor and Zelenkov's 2013 redescription of Ambiortus
Synonymization of Iteravis hutchzermeyeri and Gansis zheni-
Mortimer (online, 2014) proposed these two species of basal euornithines
from the same locality that were named within a month of each other are actually
synonyms. Gansus zheni has all of Iteravis' diagnostic characters,
including a toothless premaxilla and apparent maxillary alveoli that were not
noticed by Liu et al. (2014). Similarly, Iteravis has all of Gansus
zheni's supposed diagnostic characters as compared to Gansus yumenensis,
excluding those which are actually absent in zheni (see above).
There are also several characters which differ in their descriptions. zheni
is said to have a "small, rostrally tapered, and tear-shaped" external
naris (mistakenly cited as the internal naris), but given the odd premaxillary
shape in BMNHC Ph 1318, the premaxilla and maxilla are probably crushed in largely
ventral view (note several possible alveoli in the maxilla and the deep bone
under them which would be the palatal shelf), artificially shortening and tapering
the anterior narial edge. Liu et al. state zheni's naris posteriorly
overlaps the antorbital fenestra, which would barely be true in their interpretation,
while the labeled nasal fragment in Iteravis suggests this isn't so in
that taxon. However, the antorbital fenestral area in both specimens is a jumble
of bone fragments and multicolored sediment reflecting the fragile nature of
that region in birds and the separation of slabs which exposed it. Thus any
edge of the fenestra is impossible to identify exactly. Liu et al. claim "Unlike
other Jehol ornithuromorphs [including Iteravis] ... no pre-mandibular
ossification is visible in any of the two studied specimens." This would
be easily explainable by taphonomy as both skulls are rather poorly preserved
and the element is small and loosely connected to the dentaries. Regardless,
there are possible predentaries in each specimen- contacting the premaxillae
just in front of the dentary in BMNHC Ph 1342 and attached to the left dentary
tip projecting dorsally in BMNHC Ph 1318.
Liu et al. state zheni has "a broad ventral groove running along
the entire exposed surface" of the synsacrum, while Zhou et al. state Iteravis
has "a flat ventral surface". The latter seems true, but the 'groove'
in zheni seems to be the taphonomic collapse of the hollow interior as
seen in its tibiotarsi, humeri and ulnae. Zhou et al. states Iteravis
lacks "the cranial hook present in Gansus", while it is clearly
present in zheni's coracoids. Yet both coracoids are broken in this area
in Iteravis, and the left shows a depression in the matrix which seems
to indicate the hook's original presence. Liu et al. state zheni has
a "prominent and triangular-shaped laterocranial process", which is
absent in Iteravis. Yet this process is also absent in the illustrated
zheni specimens BMNHC Ph 1318 and 1342. Liu et al. cites BMNHC Ph 1394
as having the process, but until this specimen is illustrated, it can be considered
polymorphic at best to misinterpreted at worst. zheni is said to lack
ossified uncinate processes, whereas Iteravis is reported to preserve
"one probable uncinate process". All three specimens have ribcages
which are only partly articulated and exposed though, so its easily possible
uncinate processes are hidden if present in zheni, or that the one was
misidentified in Iteravis. Liu et al. state zheni has a deltopectoral
crest on the humerus "which extends more than one-third the total length
of the bone", while Iteravis' is described as extending "the
proximal one-third of the humerus", but the crest in the latter is almost
entirely covered by other elements so cannot be measured. Iteravis' carpometacarpus
is described as incompletely fused versus completely fused in zheni,
but the specimen is slightly smaller than zheni specimens (humeri 97%
of BMNHC Ph 1318, 95-97% of BMNHC Ph 1342) so could be expected to have less fusion.
Liu et al. say zheni lacks an extensor process on metacarpal I, while
Iteravis is said to have a small extensor process. Both taxa have the
same morphology though, which is comparable to the extensor flange of basal
paravians and not the extensor process of some euornithines.
The authors give very different lengths for Iteravis' and zheni's
cnemial crests (10 vs. 25% of tibiotarsal length), though the real apparent
values are 8% vs. 15%. The discrepancy largely seems due to zheni's tibiotarsi
being preserved in anterior view, where the collapse of the element causes a
median groove that exaggerates structures on either side such as the laterally
placed cnemial crest. Iteravis' right tibiotarsus is in medial view,
but the left element is partially covered by the sternum and has a taphonomic
concavity that extends the apparent length of the cnemial crest. Iteravis'
fibula is described as "just over half the length of the tibiotarsus",
while zheni's is said to only extend "to nearly the midshaft of
the tibia." In reality, all specimens have distal ends hidden by the tibiotarsus
so cannot be exactly measured. Liu et al. state "the proximal phalanges
of all pedal digits are longer than any of their respective distal phalanges"
in zheni, while Zhou et al. say Iteravis has a slightly longer
II-2 than II-1. Their own measurement table shows zheni is polymorphic
for this though. Iteravis is reported to have a pedal digit IV shorter
than III in contrast to zheni, but the ratio excluding unguals is 110%
in Iteravis vs. 99-106% in zheni. So Iteravis actually
has the longer digit IV, but there's more variation in zheni than difference
between it and Iteravis.
Given the lack of difference between Iteravis and zheni, they
are near certainly synonyms. Iteravis was published online October 29th
vs. zheni on November 14th. Yet Zhou et al. didn't include a ZooBank
registration. So the physical publication time is what counts, which is December
1. Thus zheni wins by 30 days.
Is zheni Gansus? Liu et al. referred zheni to Gansus
based on several characters. Of these, the hooked omal projection on the coracoid's
sternolateral process is polymorphic in Gansus yumenensis, and
the intermembral index (humerus+ulna)/(femur+tibiotarsus) of 0.9-1.1 and pedal
digit IV that is longer than digit III are polymorphic in zheni. The
posteromedially curved posterolateral sternal process is more accurately understood
as a distal expansion of the posterolateral process that is expanded medially
but not much laterally. It is also present in Jiuquanornis, Hongshanornis,
Jianchangornis, Yumenornis and Ambiortus. A metatarsal
II which extends distally only as far as the base of IV's trochlea is a synapomorphy
of birds more derived than songlingornithids. Proximal pedal phalanges which
are longer than distal phalanges is true in almost every basal euornithine,
with zheni and Gansus ironically being the only taxa with some
discordant specimens (both in digit II). The supposed absence of a coracoid
foramen is untrue in IVPP V18958, so the foramen may be hidden in the two BMNHC
specimens or this may be polymorphic in zheni. An intermetacarpal space
terminating distal to the distal end of metacarpal I is unreliable, as it varies
with metacarpal I length as well as how the laminar metacarpal III is crushed
in relation to metacarpal II. Some of these characters were miscoded by Liu
et al., and changing these ten miscodings (with zheni conservatively
coded as polymorphic for the coracoid foramen) led to zheni being basal
to Gansus and birds closer to the crown. Checking which characters supported
this, twenty-two additional miscodings were discovered. Correcting these left
zheni in this position, supported only by its gastralia. Yet Gansus
specimens may have taphonomically lost their gastralia (e.g. no crania are connected
to any), so this isn't the greatest evidence. Enforcing zheni to be Gansus
results in trees one step longer, so is basically as parsimonious. Thus neither
position is well supported, and the new combination Iteravis zheni is
used until good evidence for referring it to Gansus is presented.
References- Liu, Chiappe, Zhang, Bell, Meng, Ji and Wang, 2014. An advanced,
new long-legged bird from the Early Cretaceous of the Jehol Group (northeastern
China): Insights into the temporal divergence of modern birds. Zootaxa. 3884(3),
253-266.
Mortimer, online 2011. http://theropoddatabase.blogspot.com/2014/12/gansus-zheni-is-iteravis.html
Zhou, O'Connor and Wang, 2014. A new species from an ornithuromorph (Aves: Ornithothoraces)
dominated locality of the Jehol Biota. Chinese Science Bulletin. 59(36), 5366-5378.
O'Connor, Wang, Zhou and Zhou, 2015. Osteohistology of the Lower Cretaceous
Yixian Formation ornithuromorph (Aves) Iteravis huchzermeyeri. Palaeontologia
Electronica. 18.2.35A, 1-11.
Bailleul, Li, O'Connor and Zhou, 2019. Origin of the avian predentary
and evidence of a unique form of cranial kinesis in Cretaceous
ornithuromorphs. Proceedings of the National Academy of Sciences.
116(49), 24696-24706.
Gansus Hou and Liu, 1984
G. yumenensis Hou and Liu, 1984
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Holotype- (IVPP V6862) (~250 mm) distal tibiotarsus, phalanx I-1 (8.4
mm), pedal ungual I (4.1 mm), phalanx II-1 (10.1 mm), tarsometatarsus (31.6
mm), phalanx II-2 (11.5 mm), pedal ungual II (5 mm), phalanx III-1 (13 mm),
phalanx III-2 (10.8 mm), phalanx III-3 (8 mm), pedal ungual III (5 mm), phalanx
IV-1 (11.1 mm), phalanx IV-2 (8.6 mm), phalanx IV-3 (8.4 mm), phalanx IV-4 (7.5
mm), pedal ungual IV (4 mm)
Referred- ?(ANSP 23403) feather (Moyer et al., 2014)
(CAGS-IG-04-CM-001) tibiotarsi (one distal; 63.7 mm), fibula, metatarsal I,
phalanges I-1 (8.1 mm), pedal unguals I, tarsometatarsi (36.3 mm), phalanges
II-1 (13.9 mm), phalanges II-2 (11.9 mm), pedal unguals II (5.2 mm), phalanges
III-1 (14.2 mm), phalanges III-2 (9.4 mm), phalanges III-3 (8.7 mm), pedal unguals
III (4.8 mm), phalanges IV-1 (12 mm), phalanges IV-2 (9.7 mm), phalanges IV-3
(9.4 mm), phalanges IV-4 (~9.4 mm), pedal unguals IV (4.9 mm) (You et al., 2006)
(CAGS-IG-04-CM-002) three posterior cervical vertebrae, (dorsal series 37 mm)
ten dorsal vertebrae, three dorsal ribs, synsacrum (26.6 mm), (caudal series
15.6 mm) six caudal vertebrae, pygostyle (5.9 mm), ilia (38.2 mm), pubes (~49.1
mm), ischia (23.7 mm), femora (30 mm), tibiotarsi (one incomplete; 65.8 mm),
fibulae, phalanx I-1 (8.2 mm), pedal ungual I (4.2 mm), tarsometatarsus (You
et al., 2006)
(CAGS-IG-04-CM-003) (160 g) few posterior cervical vertebrae, (dorsal series
~38 mm) ten dorsal vertebrae, dorsal ribs, synsacrum (26.9 mm), coracoids (21.7
mm), furcula, sternum (43.4 mm), sternal ribs, humeri (~48.4 mm), radii (one
proximal), ulnae (one proximal; 52.8 mm), pisiform, carpometacarpus (25.2 mm),
proximal phalanx I-1, phalanx II-1 (11 mm), phalanx II-2 (9.6 mm), phalanx III-1,
ilia (34.6 mm), proximal pubes, proximal ischium, femur (31 mm), proximal tibiotarsus,
proximal tarsometatarsus (You et al., 2006)
(CAGS-IG-04-CM-004) (160 g) three posterior cervical vertebrae, (dorsal series
33.3 mm) ten dorsal vertebrae, dorsal ribs, synsacrum (29.2 mm), scapulae (41.7
mm), coracoids (19.2 mm), furcula, anterior sternum, sternal ribs, humeri (48
mm), radii (46.8 mm), ulnae (48.8 mm), scapholunares, pisiform, carpometacarpi (23.4
mm), phalanges I-1 (9 mm), manual unguals I (3.6 mm), phalanges II-1 (9.8 mm),
phalanges II-2 (9.1 mm), manual unguals II (3.4 mm), ilia (33.4 mm), proximal
pubis, proximal ischium (You et al., 2006)
(CAGS-IG-04-CM-008) dorsal rib, distal femur, tibiotarsus (53.4 mm), metatarsals
I (4.52, 4.4 mm), phalanges I-1 (8.2, 8.19 mm), pedal unguals I (3.51, 3.88
mm), tarsometatarsi (32.04, 31.55 mm), phalanges II-1 (13.74, 13.4 mm), phalanges
II-2 (10.81, 11.19 mm), pedal unguals II (4.46, 3.94 mm), phalanges III-1 (13.82,
14.19 mm), phalanges III-2 (8.88, 9.01 mm), phalanges III-3 (7.73, 7.65 mm),
pedal unguals III (4.46, 4.42 mm), phalanges IV-1 (11.23, 10.98 mm), phalanges
IV-2 (8.34, 8.39 mm), phalanges IV-3 (7.42, 7.35 mm), phalanges IV-4 (7.29,
7.30 mm), pedal unguals IV (4.18, 4.56 mm), scales (You et al., 2006)
(CAGS-IG-04-CM-012) specimen including coracoid, furcula, sternum and humerus
(O'Connor and Zelenkov, 2013)
(CAGS-IG-04-CM-018) tibiotarsus (61 mm), fibula (Wang et al., 2015)
(CAGS-IG-04-CM-031) partial tarsometatarsus (Wang et al., 2015)
(CAGS-IG-05-CM-014) dorsal ribs, humerus (47.8 mm), radii (one incomplete; 48.9
mm), ulnae (one incomplete; 51.1 mm), scapholunares, pisiform, carpometacarpi (23.7
mm), phalanx I-1 (9.6 mm), manual ungual I (~3.6 mm), phalanges II-1, phalanx
II-2, manual ungual II (2.8 mm), phalanx III-1 (5.8 mm), femora (29.3 mm), tibiotarsi
(63.7 mm), partial fibulae, metatarsals I, phalanges I-1 (7.3 mm), pedal unguals
I (4.1 mm), tarsometatarsi (40 mm), phalanges II-1 (15.1 mm), phalanges II-2
(one partial; 12.9 mm), pedal unguals II (4.6 mm), phalanges III-1 (13.5 mm),
phalanges III-2 (12.2 mm), phalanges III-3 (9 mm), pedal unguals III (4.6 mm),
phalanges IV-1 (12 mm), phalanges IV-2 (9.7 mm), phalanges IV-3 (one partial;
8.7 mm), phalanx IV-4 (9.3 mm), pedal unguals IV (3.7 mm), feathers, gastroliths
(Wang et al., 2015)
(CAGS-IG-06-CM-011) dorsal ribs, furcula, incomplete sternum, sternal ribs,
gastroliths (Wang et al., 2015)
(CAGS-IG-07-CM-006) scapula, coracoid (~21.6 mm), incomplete humerus (49.7 mm),
incomplete radius (52.8 mm), incomplete ulna (54.3 mm), scapholunare, pisiform, incomplete
carpometacarpus, phalanx I-1, feathers (Wang et al., 2015)
(CAGS-IG-07-CM-009) eighth dorsal vertebra, ninth dorsal vertebra, tenth dorsal
vertebra, dorsal rib, synsacrum, seven caudal vertebra, pygostyle, fused incomplete
pelvis (ilium 37.9, ischium 24.2 mm), partial ilium (Wang et al., 2015)
(CAGS-IG-07-CM-011) several dorsal vertebrae, dorsal ribs, synsacrum, incomplete
sternum, sternal ribs, ilium, pubes (47.7 mm), ischia (24.4 mm), femora (30.3
mm), tibiotarsi (61.5 mm), fibulae, metatarsals I, phalanges I-1 (8.3 mm), pedal
unguals I (3.5 mm), tarsometatarsi (one incomplete; 37.9 mm), phalanges II-1
(12.5 mm), phalanges II-2 (12.4 mm), pedal unguals II (4.6 mm), phalanges III-1
(14.1 mm), phalanges III-2 (9.4 mm), phalanges III-3 (8.6 mm), pedal unguals
III (3.1 mm), phalanges IV-1 (11 mm), phalanges IV-2 (8.9 mm), phalanges IV-3
(7.6 mm), phalanges IV-4 (8.6 mm), pedal unguals IV (3.4 mm), gastroliths (Wang
et al., 2015)
(CAGS coll.) numerous specimens including about 60 partial to incomplete skeletons
(Harris et al., 2009)
(IVPP V15074) distal tibiotarsus, pedal phalanx I-1 (~9.8 mm), tarsometatarsus
(28 mm), phalanx II-1 (12.1 mm), phalanx II-2 (8.2 mm), pedal ungual II, phalanx
III-1 (9.5 mm), phalanx III-2 (7.7 mm), phalanx III-3 (7 mm), phalanx IV-1,
phalanx IV-2, phalanx IV-3, pedal ungual IV (Li et al., 2011)
(IVPP V15075) incomplete radius, ulnar fragment, scapholunare, pisiform, carpometacarpus,
phalanx I-1, manual ungual I, incomplete phalanx II-1, phalanx II-2, manual
ungual II (Li et al., 2011)
(IVPP V15076) incomplete furcula, sternum (39.1 mm), three sternal ribs, three
partial sternal ribs (Li et al., 2011)
(IVPP V15077) distal femur, incomplete tibiotarsus, metatarsal I, pedal phalanx
I-1 (7.4 mm), pedal ungual I, tarsometatarsus (38.9 mm), phalanx II-1 (14.3
mm), phalanx II-2 (13.3 mm), partial phalanx III-1, phalanx III-2, incomplete
phalanx III-3, phalanx IV-1, phalanx IV-2, phalanx IV-3, incomplete phalanx
IV-4, pedal scales (Li et al., 2011)
(IVPP V15079) scapular fragment, incomplete humerus, radius (50.4 mm), ulna
(51.7 mm), scapholunare, carpometacarpus (mcII 24.3, mcIII 23.5 mm), phalanx I-1
(~8.3 mm), phalanx II-1 (10.3 mm), phalanx II-2 (9.9 mm), manual ungual II,
phalanx III-1 (6.1 mm) (Li et al., 2011)
(IVPP V15080) femur (31.6 mm), tibiotarsus (56.2 mm), fibula, metatarsal I,
phalanx I-1, pedal ungual I, tarsometatarsus (30.1 mm), phalanx II-1 (13.8 mm),
phalanx II-2 (12.3 mm), pedal ungual II, incomplete phalanx III-1, phalanx IV-1,
partial phalanx IV-2 (Li et al., 2011)
(IVPP V15081) partial radius, partial ulna, scapholunare, pisiform, carpometacarpus
(mcI 5.3, mcII 28.6, mcIII 26.9 mm), phalanx I-1 (12 mm), manual ungual I, phalanx
II-1 (12.7 mm), phalanx II-2 (11.1 mm), manual ungual II, phalanx III-1 (Li
et al., 2011)
(IVPP V15083) metatarsal I, pedal phalanx I-1 (6.6 mm), pedal ungual I, tarsometatarsus
(29.1 mm), phalanx II-1 (11.5 mm), phalanx II-2 (10 mm), pedal ungual II, phalanx
III-1 (12.2 mm), phalanx III-2 (8 mm), phalanx III-3 (6.2 mm), pedal ungual
III, phalanx IV-1 (10.2 mm), phalanx IV-2 (7.9 mm), phalanx IV-3 (6.9 mm), phalanx
IV-4 (7.1 mm), pedal ungual IV, skin impressions (Li et al., 2011)
(IVPP V15084) femur (~31.6 mm), tibiotarsus (42.2 mm), fibula, metatarsal I,
phalanx I-1 (7.9 mm), pedal ungual I, tarsometatarsus (36.7 mm), phalanx II-1
(9.7 mm), phalanx II-2 (9.8 mm), pedal ungual II, phalanx III-1 (11.7 mm), phalanx
III-2 (8.5 mm), phalanx III-3 (6.8 mm), pedal ungual III, phalanx IV-1 (9 mm),
phalanx IV-2 (5.6 mm), phalanx IV-3 (5.2 mm), phalanx IV-4 (4.7 mm), pedal ungual
IV (Li et al., 2011)
?(IVPP V26199) skull (37.56 mm), sclerotic ossicles, mandibles (31.46
mm), urohyal, hyoids (19.93 mm), atlas, axis, third cervical vertebra,
feathers (O'Connor et al., 2021)
? two feathers (Barden et al., 2011)
Diagnosis- (after Wang et al., 2015) pygostyle narrow throughout length
with dorsal spinous ridge; sternum with well-developed anteroolateral and postcostal
processes; posterolateral sternal processes curved medially; sternum with pair
of posterior fenestrae; coracoid with anteriorly hooked lateral process; tibiotarsus
long, with two strongly proximally projected cnemial crests; position of metatarsal
II trochlea high and plantarly displaced relative to metatarsal III trochlea; pedal digit IV longest;
pedal unguals with pointed flexor tubercles.
Comments- The holotype was discovered in 1981 and described by Hou and
Liu (1984), who believed birds were divided into land and water clades, with
Archaeopteryx ancestral to the former and Gansus
ancestral to the latter (except hesperornithines). Hou (1997) placed it
sister to Ornithurae in his phylogram, and redescribed the taxon. Hope
(2002) believed the specimen to be an ornithurine, but not an avian.
Clarke (2002) coded the holotype for her matrix, finding it to be a
carinate more derived than Ichthyornis,
but less than Iaceornis
and Aves. She noted the specimen was poorly preserved and "glued into
the slab after being removed and repaired, obscuring almost all
morphologies." You et al. (2005) coded the specimen for Chiappe's
matrix and found it to be a euornithine outside Ornithurae. You et al. (2006) describe several additional far more
complete specimens of this genus, which they place as an ornithurine sister to Carinatae. Ji et al. (2006) later described one
of the new specimens (CAGS-IG-04-CM-008) in detail, noting it preserves
webbed feet. Bailleul et al. (2019) figured mandibles in their
supplementary information as an unpublished specimen of Gansus,
but these were later described by O'Connor et al. (2021, 2022)
as a new taxon Brevidentavis (originally "Brachydontornis").
Harris et al. (2009) give preliminary data on more new specimens which
include cranial elements, but these ended up being described as Meemannavis (IVPP V26198) and Euornithes indet. (IVPP V26194-26196)
by O'Connor et al.. The latter three specimens belong to at least
two taxa (with IVPP V26196 being distinct in cervical proportions), but
which of these (if either) are Gansus
is unknown due to a lack of comparable material. However,
O'Connor et al. did describe another skull discovered in 2004 or 2005
with anterior cervicals (IVPP V26199) that they referred to Gansus based on similarity to Iteravis.
References- Hou and Liu, 1984. A new fossil bird from Lower Cretaceous
of Gansu and early evolution of birds. Scientia Sinica. 27, 1296-1302.
Hou, 1997. Mesozoic birds of China. Taiwan Provincial Feng Huang Ku Bird Park.
Taiwan: Nan Tou. 228 pp.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
Zhou and Hou, 2002. The discovery and study of Mesozoic birds in China. in Chiappe
and Witmer, (eds.). Mesozoic Birds- Above the Heads of Dinosaurs. University
of California Press, Berkeley, Los Angeles, London. 160-183.
You, O'Connor, Chiappe and Ji, 2005. A new fossil bird from the Early Cretaceous
of Gansu Province, northwestern China. Historical Biology. 17, 7-14.
Harris, You and Lamanna, 2006. New specimens of the ornithuran bird Gansus
yumenensis from the Xiagou Formation (Lower Cretaceous) of Gansu province,
China. Journal of Vertebrate Paleontology. 26(3), 72A.
Ji, Ji, You, Lu and Yuan, 2006. Webbed foot of an Early Cretaceous ornithurine
bird Gansus from China. Geological Bulletin of China. 25(11), 1295-1298.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
Harris, Lamanna, Li and You, 2009. Avian cranial material and cranial cervical
vertebrae from the Lower Cretaceous Xiagou Formation of Gansu Province, China.
Journal of Vertebrate Paleontology. 29(3), 111A.
Barden, Wogelius, Edwards, Manning and van Dongen, 2011. Preservation in the
feathers of the Early Cretaceous bird Gansus yumenensis. Journal of Vertebrate
Paleontology. Program and Abstracts 2011, 66.
Li, Zhang, Zhou, Li, Liu and Wang, 2011. New material of Gansus and a
discussion on its habit. Vertebrata PalAsiatica. 49(4), 435-445.
O'Connor and Zelenkov, 2013. The phylogenetic position of Ambiortus:
Comparison with other Mesozoic birds from Asia. Paleontological Journal. 47(11),
1270-1281.
Moyer, Zheng, Johnson, Lamanna, Li, Lacovera and Schweitzer, 2014. Melanosomes
or microbes: Testing an alternative hypothesis for the origin of microbodies
in fossil feathers. Scientific Reports. 4, 4233.
Wang, O'Connor, Li and You, 2015. New information on postcranial skeleton of
the Early Cretaceous Gansus yumenensis (Aves: Ornithuromorpha), Historical
Biology. DOI: 10.1080/08912963.2015.1006217
Bailleul, Li, O'Connor and Zhou, 2019. Origin of the avian predentary
and evidence of a unique form of cranial kinesis in Cretaceous
ornithuromorphs. Proceedings of the National Academy of Sciences.
116(49), 24696-24706.
O'Connor, Lamanna, Harris, Hu, Bailleul, Wang and You, 2021. First
avian skulls from the Lower Cretaceous Xiagou Formation, Gansu, China.
The Society of
Vertebrate Paleontology Virtual Meeting Conference Program, 81st Annual
Meeting. 196.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
(online 2021). Avian skulls represent a diverse ornithuromorph fauna
from the
Lower Cretaceous Xiagou Formation, Gansu Province, China. Journal of
Systematics and Evolution. 60(5), 1172-1198.
Ambiortus Kurochkin, 1982
A. dementjevi Kurochkin, 1982
Hauterivian-Barremian, Early Cretaceous
Andaikhudag (= Anda Khooduk) Formation, Mongolia
Holotype- (PIN 3790-271/272) (~270 mm) seven cervical vertebrae, three
or four anterior dorsal vertebrae, dorsal rib fragments, incomplete scapula,
incomplete coracoid, incomplete sternum, partial furcula, proximal humerus (~67
mm), incomplete radius, incomplete ulna, proximal carpal, incomplete carpometacarpus,
phalanx II-1, phalanx II-2, manual ungual II, body feathers, remiges
Diagnosis- (after Kurochkin, 2000) transverse ligamental fossa proximal
to bicipital crest.
(after O'Connor and Zelenkov, 2013) posterolateral sternal process wide; posterolateral
sternal process curved medially; ventral edge of proximal end of humerus strongly
developed and with distinct tubercle on its cranial surface; transverse groove
short, fossa-like, and runs dorsoventrally; pneumotricipital fossa of humerus
not developed; deltopectoral crest projected dorsally; bicipital crest distally
ends abruptly.
Other diagnoses- Kurochkin (2000) included several additional characters
in his diagnosis. Most basal euornithines (e.g. Patagopteryx, Apsaravis,
basal Aves) share dorsoventrally compressed acromia. The acromia of Patagopteryx
and Yixianornis are equally long, while that of Apsaravis is even
longer. The scapular blades of most basal euornithines except Patagopteryx
are equally slender. The longitudinal groove in the posterolateral scapular
blade is also present in most basal euornithines (e.g. Patagopteryx,
Archaeorhynchus, Apsaravis, Yixianornis). The procoracoid
process is equally long and broad in Hongshanornis and songlingornithids.
The absent capital groove is shared with Apsaravis. Several other basal euornithines have a fossa instead of a transverse ligamental groove, but
that of Apsaravis, Gansus and Ichthyornis differ in being
on the bicipital crest, not proximal to it. The proximal fusion of the carpometacarpus
is symplesiomorphic for avialans, while the dorsoventrally
compressed manual phalanx II-1 is seen in euornithines except Patagopteryx.
O'Connor and Zelenkov (2013) proposed other characters. The hooked acromion
is shared with Apsaravis. The procoracoid process is similarly angled
in e.g. songlingornithids.
Comments- The holotype was discovered in 1977 and described by Kurochkin
(1982) as a carinate (which was equivalent to Ornithurae then as the few known
fragments of taxa intermediate between Archaeopteryx and hesperornithines
were not recognized as such). Cracraft (1986) was the first to include it in
a phylogenetic analysis, which placed Ambiortus in an unresolved trichotomy
with Ichthyornis and Aves (his Neognathae), though enantiornithines were
also placed in this position because no other avialans
were known and hesperornithines were placed too basally based on their flightlessness.
Sanz and Buscalioni (1992) found Ambiortus to have an uncertain position
compared to Ornithurae and Enantiornithes in their cladogram.
Ambiortus a palaeognath? Kurochkin referred it to Palaeognathae
in 1985 based on several characters. The long pointed acromion is also found
in songlingornithids and anatoids. The supposedly wide and short acrocoracohumeral
ligament scar is equally long in other basal euornithines (e.g. Archaeorhynchus,
Apsaravis, Yixianornis), and mediolaterally narrower as in Gansus.
The longitudinal groove on the ventral acrocoracoid face is homologized to a
pit in palaeognaths, but a similar depressed area is present in Archaeorhynchus
and Yixianornis. In his 1995 paper, Kurochkin added a few supposed palaeognath
characters. The bicipital crest was said to be absent, but is the "slightly
pronounced cranial tubercle" he described in 1999. The deltopectoral crest
begins just as proximally in other basal euornithines. The glenoid facet
on the coracoid is displaced dorsally in Apsaravis and Ichthyornis
as well. The short and wide acrocoracoid is symplesiomorphic for euornithines.
The hypocleidium is also absent in Archaeorhynchus, Yanornis,
Gansus and Ichthyornis. In 1999, Kurochkin added yet more supposed
palaeognath characters in his description. The dorsoventrally flattened acromion
is symplesiomorphic for euornithines (e.g. Patagopteryx, Apsaravis,
Galliformes). A dorsal tubercle on the acromion is also present in Iaceornis
and Anas. The well developed ventral tuber is also present in Archaeorhynchus,
Yixianornis and Alamitornis. The "remarkable cranial tubercle"
with an anterior pit is the bicipital crest, which also has such a pit in enantiornithines
and Apsaravis. The strongly laterally projecting, posteriorly placed
"caudal transverse processes" seem to be laterally flared postzygapophyseal
processes instead, as seen in Ichthyornis.
Hope (2002) states several characters (capital groove; pneumotricipital fossa;
ventral tuber; bicipital crest) are poorly developed in Ambiortus, Ichthyornis,
palaeognaths and galliforms compared to most neognaths and enantiornithines.
She attributes this either to convergence in the latter groups or placement
of Ambiortus in Palaeognathae. Yet the first three characters are well
developed in Lithornis and tinamiforms, while the bicipital crest is
extremely reduced in neognaths in addition to tinamiforms. Given the distribution
of characters in recently discovered basal euornithines, Ambiortus
and Apsaravis lost their capital grooves independently of ratites, pneumotricipital
fossae developed convergently in some enantiornithines and Aves, ventral tuber
size is quite homoplasic, and a low bicipital crest is primitive for euornithines.
In conclusion, nearly all of the proposed palaeognath characters in Ambiortus
are symplesiomorphic, with the exception of the dorsal acromion tubercle.
Ambiortus an ichthyornithine? Martin (1987) believed Ambiortus
was the sister taxon to Apatornis (based on the Iaceornis holotype)
within Ichthyornithiformes because of their long acromia, but those of Apsaravis,
Yixianornis and Patagopteryx are also elongate, as are most enantiornithes'.
Chatterjee (1999) found Ambiortus to clade with Ichthyornithiformes in
his analysis. This was based on the supposedly amphicoelous cervicals (actually
heterocoelous in Ambiortus- Kurochkin, 1999) and absent bicipital crest
(actually present in both Ambiortus and Ichthyornis).
Ambiortus a basal euornithine? Sereno and Rao (1992) found
Ambiortus to be a euornithine outside of Ornithurae
based on an unpublished phylogenetic analysis, but this cannot be evaluated.
Elzanowski (1995) placed Ambiortus in basal Euornithes (his Neornithes),
excluded from Aves (his Neognathae) due to the dorsally projecting deltopectoral
crest and lack of an extensor process on metacarpal I, and excluded from Carinatae
(unnamed node in his cladogram, not equivalent to his Carinatae) based on the
more laterally facing scapular glenoid and prominent acromion process. The deltopectoral
crest is anteriorly projecting in patagopterygids, but otherwise seems to be
an unambiguous avian character. As described and illustrated by Kurochkin (1999),
Ambiortus actually has an extensor process, albeit a low one. Small acromia
are also present in Archaeorhynchus and Hongshanornis but absent
in the very derived Iaceornis, so show some homoplasy. The glenoid does
seem less dorsally angled than carinates.
Chiappe (2001) placed Ambiortus closer to Aves than Patagopteryx
based on the procoracoid process (also absent in Apsaravis) and proximally
globe-shaped humeral head. It was excluded from Carinatae due to the absent
extensor process (again miscoded, as it is actually present but low) and the
presence of manual ungual II (miscoded as absent in Ichthyornis based
on an Iaceornis element, but still valid to exclude Ambiortus
from an Iaceornis+Aves clade). While placed between Hesperornithes and
Ichthyornis on his cladogram, Chiappe later (2002) noted it could equally
parsimoniously be placed as sister to Ornithurae.
Clarke (2002) first included Ambiortus in her unpublished thesis' matrix,
finding it positioned above Patagopteryx, but in a polytomy with Apsaravis,
Gansus, Hesperornithes, Ichthyornis, Limenavis and
Iaceornis+Aves. It was first published in a version of Clarke's matrix
by You et al. (2006), which presents Ambiortus as falling out more derived
that Patagopteryx and Hongshanornis, but more basal than Apsaravis,
songlingornithids, Gansus and ornithurines. The supplementary
information indicates it also emerged as a songlingornithid in some trees. In
the first position, Ambiortus was more derived than Patagopteryx
and Hongshanornis based on the absent hypocleideum, proximally domed
humeral head, extensor process on metacarpal I, and highly compressed manual
phalanx II-1. It was less derived than Aves based on several characters- acrocoracoid
process not hooked medially; pit on bicipital crest absent (miscoded in Ambiortus);
extensor process on metacarpal I not projecting; thick metacarpal III (which
cannot actually be coded, as only the fused base is preserved); phalanx II-2
longer than II-1 (miscoded in Ambiortus).
While several characters were miscoded by various authors, Ambiortus
does seem excluded from Aves based on- scapular glenoid less dorsally angled;
acrocoracoid not medially hooked; dorsally projecting deltopectoral crest; low
extensor process on metacarpal I; manual ungual II present.
References- Kurochkin, 1982. Novyy otryad ptits iz nizhnego mela Mongolii.
Doklandy Akademii Nauk SSSR. 262(2), 452-455.
Kurochkin, 1983. New order of birds from the Lower Cretaceous in Mongolia. Palaeontological
Journal. 17, 215-218.
Kurochkin, 1985. Lower Cretaceous birds from Mongolia and their evolutionary
significance. XVIII Congressus Internationalis Ornithologicus: Programme. 1,
191-199.
Kurochkin, 1985. A true carinate bird from Lower Cretaceous deposits in Mongolia
and other evidence of Early Cretaceous birds in Asia. Cretaceous Research. 6,
271-278.
Cracraft, 1986. The origin and early diversification of birds. Paleobiology.
12, 383-399.
Martin, 1987. The beginning of the modern avian radiation. Documents des Laboratoires
de Geologie de la Faculte des Sciences de Lyon. 99, 9-20.
Sanz and Buscalioni, 1992. A new bird from the Early Cretaceous of Las Hoas,
Spain, and the early radiation of birds. Palaeontology. 35, 829-845.
Sereno and Rao, 1992. Early evolution of avian flight and perching: New evidence
from Lower Cretaceous of China. Science. 255, 845-848.
Elzanowski, 1995. Cretaceous birds and avian phylogeny. Courier Forschungsinstitut
Senckenberg. 181, 37-53.
Kurochkin, 1995. Synopsis of Mesozoic birds and early evolution of class Aves.
Archaeopteryx. 13, 47-66.
Kurochkin, 1996. Morphological differentiation of palaeognathous and neognathous
birds. Courier Forschungsinstitut Senckenberg. 181, 79-88.
Kurochkin, 1999. The relationships of the Early Cretaceous Ambiortus
and Otogornis (Aves: Ambiortiformes). In Olson (ed.). Avian Paleontology
at the Close of the 20th Century: Proceedings of the 4th International Meeting
of the Society of Avian Paleontology and Evolution. Smithsonian Contributions
to Paleobiology. 89, 275-284.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. In Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge University Press.
533-559.
Chiappe, 2001. Phylogenetic relationships among basal birds. In Gauthier and
Gall (eds). New perspectives on the origin and early evolution of birds: Proceedings
of the international symposium in honor of John H. Ostrom. New Haven: Peabody
Museum of Natural History. 125-139.
Chiappe, 2002. Basal bird phylogeny: Problems and solutions. In Chiappe and
Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 448-472.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
O'Connor and Zelenkov, 2013. The phylogenetic position of Ambiortus:
Comparison with other Mesozoic birds from Asia. Paleontological Journal. 47(11),
1270-1281.
Hongshanornithidae O'Connor, Wang, Chiappe, Gao, Meng, Cheng and Liu, 2009
Other definition- (Hongshanornis longicresta + Longicrusavis houi) (O'Connor,
Gao and Chiappe, 2010)
Comments- O'Connor et al. (2009) propose Hongshanornithidae to include
Hongshanornis and the at-the-time undescribed Longicrusavis. This
is based on- dorsal dentary convex and dorsal surangular concave (also in Archaeorhynchus,
many enantiornithines and probably Patagopteryx); posterolateral sternal
processes not expanded much distally (probably symplesiomorphic as it is found
in Archaeorhynchus, Gansus and basal enantiornithines); manus
longer than humerus (probably symplesiomorphic as it is found in non-ornithothoracines,
Protopteryx, Pengornis and Longipteryx); forelimb/hindlimb
ratio (humerus+ulna / femur+tibia) <90% (also in Patagopteryx and
hesperornithines). O'Connor et al. (2010) later described Longicrusavis
and used the same matrix, also adding the manual formula of 2-3-2 to the diagnosis
for Hongshanornithidae. Yet this is plesiomorphic, also being found in basal
enantiornithines. Notably, Archaeorhynchus was not included in their
matrix, Patagopteryx was coded as lacking the mandibular character even
though the surangular is dorsally concave and the dentary missing, no enantiornithines
with the mandibular character were included, Shanweiniao and Longipteryx
were miscoded as having greatly expanded posterolateral sternal processes, and
basal enantiornithines that have long manus and sternal processes with small
expansions were not included.
References- O'Connor, Wang, Chiappe, Gao, Meng, Cheng and Liu, 2009. Phylogenetic support
for a specialized clade of Cretaceous enantiornithine birds with information
from a new species. Journal of Vertebrate Paleontology. 29(1), 188-204.
O'Connor, Gao and Chiappe, 2010. A new ornithuromorph (Aves: Ornithothoraces)
bird from the Jehol Group indicative of higher-level diversity. Journal of Vertebrate
Paleontology. 30(2), 311-321.
Archaeornithura Wang,
Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou, 2015a
A. meemannae Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and
Zhou, 2015a
Late Hauterivian, Early Cretaceous
Sichakou Sedimentary Member of the Huajiying Formation, Hebei, China
Holotype- (STM 7-145) fragmentary posterior skull, cervical vertebrae,
dorsal vertebrae, dorsal ribs, uncinate processes, gastralia, caudal vertebrae,
pygostyle, partial scapula, coracoids (15.4 mm), furcula, partial sternum, humeri
(25.9 mm), radii (23.9 mm), ulnae (25.8 mm), pisiform, carpometacarpi (13.1 mm),
phalanges I-1 (6 mm), manual unguals I (3 mm), phalanges II-1 (6.6 mm), phalanges
II-2 (7.6 mm), manual ungual II (2.4 mm), phalanges III-1 (3.3 mm), partial
ilium, pubes, femora (23.8 mm), tibiotarsi (38 mm), fibulae, metatarsals I,
phalanges I-1, pedal unguals I, tarsometatarsi (23 mm), phalanges II-1, phalanges
II-2, pedal unguals II, phalanges III-1, phalanges III-2, phalanges III-3, pedal
unguals III, phalanges IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4,
pedal unguals IV, pedal claw sheaths, body feathers, remiges, retrices
Paratype- (STM 7-163) fragmentary posterior skull, ten cervical vertebrae,
dorsal vertebrae, dorsal ribs, uncinate processes, gastralia, synsacrum, six
caudal vertebrae, pygostyle, coracoids (12.7 mm), furcula, partial sternum,
sternal ribs, humeri (27.5 mm), radii (26 mm), ulnae (28.3 mm), scapholunare, carpometacarpi
(13.8 mm), phalanges I-1 (7.6 mm), manual ungual I (3.9 mm), phalanges II-1
(6.8 mm), phalanges II-2 (7 mm), manual unguals II (3 mm), manual claw sheaths,
pubes, ischia, femora, tibiotarsi (37.5 mm), fibulae, metatarsals I, phalanges
I-1, pedal unguals I, tarsometatarsi, phalanges II-1, phalanges II-2, pedal
ungual II, phalanges III-1, phalanges III-2, phalanges III-3, pedal unguals
III, phalanges IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4, pedal unguals
IV, pedal claw sheaths, body feathers, remiges
Diagnosis- (after Wang et al., 2015a) differs from Hongshanornis
and Longicrusavis in- anterior margin of sternum strongly vaulted.
differs from from Hongshanornis and Parahongshanornis in- posteromedian
sternal process well developed and squared.
differs from Hongshanornis, Parahongshanornis and Tianyuornis
in- manual digit I extends further distally than metacarpal II.
differs from Hongshanornis, Longicrusavis and Tianyuornis in-
manual phalanx II-2 longer than II-1; shorter femur relative to tarsometatarsus.
Comments- The type specimens were acquired from a dealer. Wang et al.
(2015) added the taxon to a version of O'Connor's bird analysis and found it
to be a hongshanornithid.
References- Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou,
2015a. The oldest record of Ornithuromorpha from the Early Cretaceous of China.
Nature Communications. 6:6987.
Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou, 2015b. The oldest
record of Ornithuromorpha with implications for evolutionary rate of Early Cretaceous
birds. Journal of Vertebrate Paleontology. Program and Abstracts 2015, 233.
Tianyuornis Zheng, O'Connor, Wang,
Zhang and Wang, 2014
T. cheni Zheng, O'Connor, Wang, Zhang and Wang, 2014
Late Barremian-Early Aptian, Early Cretaceous
Jianshangou Beds of Yixian Formation, Inner Mongolia, China
Holotype- (STM7-53) (subadult) skull (30 mm), mandibles, several cervical
vertebrae, cervical ribs, several dorsal vertebrae, dorsal ribs, uncinate processes,
gastralia, synsacrum, caudal vertebrae, pygostyle (3.3 mm), scapula, coracoids
(11, 11.5 mm), partial furcula, sternum (19 mm), sternal ribs, humeri (25.4
mm), radii (24.6 mm), ulnae (26.4 mm), scapholunare, pisiform, metacarpal I (2.7 mm),
phalanges I-1 (6.6 mm), manual unguals I (2.9 mm), carpometacarpi (13.2 mm;
II 13, III 10.7 mm), phalanges II-1 (6.9 mm), phalanges II-2 (7 mm), manual
ungual II (~2.6 mm), phalanges III-1 (3.3 mm), phalanx III-2, incomplete ilium,
partial pubes, femora (24.8 mm), tibiotarsi (39 mm), fibula, metatarsal I (3.5
mm), phalanges I-1 (4.1 mm), pedal unguals I (2.5 mm), tarsometatarsi (II 17.8,
III 23.1, IV 18.5 mm), phalanges II-1 (6 mm), phalanges II-2 (5.1 mm), pedal
unguals II (3.2 mm), phalanges III-1 (~7.5 mm), phalanx III-2 (~5.3 mm), phalanx
III-3 (4.5 mm), pedal ungual III (4 mm), phalanx IV-1 (~3.8 mm), phalanx IV-2
(3.5 mm), phalanx IV-3 (3.3 mm), phalanx IV-4 (3 mm), pedal ungual IV (2.6 mm),
remiges, retrices
Diagnosis- (after Zheng et al., 2014) toothed upper and lower jaws; premaxillary
and maxillary teeth much larger than dentary teeth; anterior half of dentary
straight; uncinate processes elongate, crossing two adjacent ribs; coracoid
length/width ratio ~1.6; U-shaped furcula without hypocleideum; sternum with
anterior margin angled ~96 degrees; posterolateral sternal process distally
expanded.
Comments- Zheng et al. (2014) refer this new taxon to Hongshanornithidae
without a phylogenetic analysis, but as I argue here, that family is mostly
based on symplesiomorphies. Tianyuornis even lacks the supposed hongshanornithid
character of posterolateral sternal processes not expanded much distally. Also
note Hongshanornis has recently been shown to have both upper and lower
teeth, so at least this character is not diagnostic of Tianyuornis. However,
Wang et al. (2015) added it to O'Connor's bird analysis and found it to fall
within Hongshanornithidae as the sister of Archaeornithura.
References- Zheng, O'Connor, Wang, Zhang and Wang, 2014. New information
on Hongshanornithidae (Aves: Ornithuromorpha) from a new subadult specimen.
Vertebrata PalAsiatica. 52(2), 217-232.
Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou, 2015. The oldest record
of Ornithuromorpha from the Early Cretaceous of China. Nature Communications.
6:6987.
Parahongshanornis
Li, Wang and Hou, 2011
P. chaoyangensis Li, Wang and Hou, 2011
Early Albian, Early Cretaceous
Chaoyang, Jiufotang Formation, Liaoning, China
Holotype- (PMOL.AB00161) eight cervical vertebrae, dorsal ribs, synsacrum,
incomplete scapula, coracoids (14.7 mm), furcula (~13 mm), sternum, sternal
ribs, humeri (one partial; 29.4 mm), radii (one partial; 26.8 mm), ulnae (one
partial; 28.4 mm), scapholunares, pisiforms, metacarpals I (3.4 mm), phalanges I-1
(6.7 mm), manual unguals I (2.7 mm), carpometacarpi (II 12.3, III 11.4 mm),
phalanges II-1 (7.1 mm), phalanges II-2 (8 mm), manual unguals II (2.6 mm),
phalanges III-1 (3.5 mm), phalanges III-2 (1.3 mm), ilia, pubes (24 mm), ischium,
femora (24.8 mm), tibiotarsi (41.3 mm), fibulae (20.7 mm), metatarsals I (3.2
mm), phalanges I-1, pedal unguals I, tarsometatarsi (II 20.3, III 21.2, IV 20.2
mm), phalanges II-1, phalanges II-2, pedal unguals II, phalanges III-1, phalanges
III-2, phalanges III-3, pedal unguals III, phalanges IV-1, phalanges IV-2, phalanges
IV-3, phalanges IV-4, pedal unguals IV, body feathers
Diagnosis- (after Li et al., 2011) coracoid elongate (length/distal width
2.3) (also in Hongshanornis); furcula anteroposteriorly compressed proximally
(also in Yanornis); deep groove along clavicular symphysis (also in Yanornis);
fibula close to half tibiotarsal length (also in Longicrusavis).
Other diagnoses- Li et al. (2011) listed other characters in the diagnosis
as well. A U-shaped furcula, elongate sternum, xiphoid sternal processes, short
posteromedial sternal processes (which create two pairs of posterior excavations),
distally expanded posterolateral sternal processes, anteriorly extensive sternal
keel, subequally long metacarpals II and III, straight and slender manual phalanx
II-2, opisthopubic pelvis and a pubic boot are primitive for euornithines.
The forelimb is also short in Patagopteryx, Hongshanornis and
Longicrusavis. Manual phalanx II-1 is also short in Yanornis and
Gansus. The tibiotarsofemoral ratio is also high in Hongshanornis,
Longicrusavis, Yanornis and Gansus. The tibiotarsus is
also slender in Hongshanornis, Longicrusavis, Yixianornis
and Gansus. The tarsometatarsus is shorter in Archaeorhynchus,
Jianchangornis, Patagopteryx, Longicrusavis, Yanornis
and Yixianornis.
Comments- Li et al. (2011) referred this taxon to Hongshanornithidae
based on the U-shaped elongated furcula and short forelimb. The former is also
true in Archaeorhynchus, Yanornis and Jianchangornis. The
latter is also true in Patagopteryx. Wang et al. (2015) added it to O'Connor's
bird analysis and found it to clade in Hongshanornithidae as sister to other
members except Hongshanornis.
O'Connor
et al. (2005) mention a new euornithine (as an ornithuromorph) in an SVP abstract, distinct
from most in having a tibiotarsus longer than the humerus.
While the authorship is the same as Longicrusavis from JVP five years
later, the locality of near Chaoyang in the Jiufotang Formation matches
Parahongshanornis instead (Longicrusavis was found near Lingyuan in the
Yixian Formation). The reported forelimb/hindlimb ratio is also slightly closer to Parahongshanornis than Longicrusavis
(79% versus 80% and 77%), but whether this is the holotype that was
described by new authors six years later or another specimen is unknown.
References- O'Connor, Chiappe and Gao, 2005. A new fossil bird from the
Lower Cretaceous Jiufotang Formation, Liaoning Province, northeastern China.
Journal of Vertebrate Paleontology. 25(3), 97A.
Li, Wang and Hou, 2011. A new ornithurine bird (Hongshanornithidae)
from the Jiufotang Formation of Chaoyang, Liaoning, China. Vertebrata PalAsiatica.
49(2), 195-200.
Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou, 2015. The oldest record
of Ornithuromorpha from the Early Cretaceous of China. Nature Communications.
6:6987.
Hongshanornis Zhou and
Zhang, 2005
H. longicresta Zhou and Zhang, 2005
Late Barremian-Early Aptian, Early Cretaceous
Jianshangou Beds of Yixian Formation, Inner Mongolia, China
Holotype- (IVPP V14533) (88 g) skull, mandibles, hyoids, at least seven
cervical vertebrae, dorsal vertebrae, dorsal ribs, uncinate processes(?), gastralia,
sacrum, caudal vertebrae, pygostyle, scapulae, coracoid, furcula, sternum, humeri
(26 mm), radii, ulnae (24 mm), scapholunare, pisiform(?), carpometacarpi (13 mm), phalanges
I-1, manual unguals I, phalanges II-1, phalanges II-2, manual unguals II, phalanges
III-1, phalanges III-2, ilia, pubes (24 mm), ischium, femora (22 mm), tibiotarsi
(38 mm), fibula, metatarsal I, phalanges I-1, pedal unguals I, tarsometatarsus
(22 mm), phalanges II-1, phalanges II-2, pedal unguals II, phalanges III-1,
phalanges III-2, phalanges III-3, pedal unguals III, phalanges IV-1, phalanges
IV-2, phalanges IV-3, phalanges IV-4, pedal ungual IV, body feathers, remiges,
retrices
Referred- (DNHM D2945/6) skull (30.5 mm), mandible, hyoid, eight cervical
vertebrae, nine dorsal vertebrae, dorsal ribs, four uncinate processes, synsacrum,
scapulae, coracoids, furcula, incomplete sternum, six sternal ribs, humeri (24.6
mm), radii, ulna (24.5 mm), scapholunare, carpometacarpus (13 mm), phalanx I-1, manual
ungual I, phalanx II-1, phalanx II-2, manual ungual II, phalanx III-1, phalanx
III-2, manual claw sheaths, partial ilia, distal pubes, femora (22 mm), tibiotarsi
(35.5 mm), fibulae, metatarsal I, phalanges I-1, pedal unguals I, tarsometatarsi
(20.6 mm), phalanges II-1, phalanges II-2, pedal unguals II, phalanges III-1,
phalanges III-2, phalanges III-3, pedal unguals III, phalanges IV-1, phalanges
IV-2, phalanges IV-3, phalanges IV-4, pedal unguals IV, body feathers, remiges,
retrices, gastroliths (O'Connor et al., 2010)
(STM coll.) over 24 specimens (Zheng et al., 2011)
Diagnosis- (from Zhou and Zhang, 2005) dentary ventrally curved (also
in Archaeorhynchus); posterolateral sternal processes angled medially;
hypocleidium present; forelimb/hindlimb (humerus+ulna / femur+tibiotarsus) ratio
83-85%.
Other diagnoses- Zhou and Zhang (2005) included additional characters
in their diagnosis. A premaxilla with a slender and pointed anterior end is
also present in Archaeorhynchus, Longicrusavis, songlingornithids and
hesperornithines. Though they state both the premaxilla and maxilla are toothless,
O'Connor et al. (2010) note alveoli are present in both. Similarly, contra Zhou
and Zhang, Chiappe et al. (2014) find teeth in the dentary. A sternum with two
pairs of posterior excavations is primitive for ornithothoracines. Chiappe et
al. note the supposed tapering posterolateral process on the holotype's sternum
is too poorly preserved to verify, and DNHM D2945/6 has either an expanded process
or a fenestra. STM 35-3 shows expanded ends. A U-shaped furcula and laterally
expanded manual phalanx II-1 are primitive for euornithines. Manual phalanx
II-2 is also sinuously curved in Longicrusavis, Yixianornis and Gansus.
Comments- Note Wang et al. (2014) incorrectly call DNHM D2945/6 the paratype,
but it is not as it was not mentioned in the original description.
Miscoded originally? You et al. (2006) changed numerous codings for Hongshanornis
based on personal observation from Chiappe and O'Connor. These include making
the following states uncertain- dentary teeth absent (untrue- Chiappe et al.,
2014); amount of upper beak formed by premaxilla (yet the suture seems clear
and DNHM D2945/6 also has a short ventral margin); length of dorsal premaxilla
process (yet the tip of the process is clearly seen); length of dorsal maxilla
process; anterior extent of splenial; amphicoely of cervical centra; length/width
ratio of dorsal centra (DNHM D2945/6 shows they were elongate); presence of
uncinate processes (present in DNHM D2945/6); number of free caudal vertebrae
(yet the pygostyle's position indicates it must be small); epicleidial morphology
(hidden by matrix- Nesbitt et al., 2009); presence of procoracoid process; presence
of lateral coracoid process (it seems absent in the photo of the holotype, but
is definitely present in DNHM D2945/6); length of acromion process (long in
DNHM D2945/6); depth of sternal keel; orientation of deltopectoral crest (yet
it seems obviously dorsally projected in the photo and in DNHM D2945/6); prominence
of bicipital crest; development of semilunate dorsal condyle on ulna (present
in DNHM D2945/6); presence of pisiform; fusion of carpometacarpus
(completely fused in DNHM D2945/6); convexity of medial
edge of metacarpal I (it seems convex in the photo, but is definitely concave
in DNHM D2945/6); ginglymoidy of metacarpal I (seems
flat in DNHM D2945/6); dorsal contact of ilia (at least unfused to sacral neural
spines in DNHM D2945/6); orientation of postacetabular process; pubic orientation
(the pubis is in anterior view, though O'Connor et al. state they are retroverted;
definitely retroverted in DNHM D2945/6); cross sectional shape of pubis (transversely compressed in DNHM D2945/6);
presence of ilioischiadic fenestra; presence of proximodorsal ischial process
(though O'Connor et al. state one is absent); presence of obturator flange;
tibiotarsal fusion (astragalocalcaneum fused to tibia but with visible suture
posteriorly in DNHM D2945/6); comparative width of tibiotarsal condyles (lateral
largest in DNHM D2945/6); tarsometatarsal fusion (yet it seems present in the
photo and is complete in DNHM D2945/6); absence of metatarsal V (yet the holotype
and DNHM D2945/6 are complete enough to make its absence probably not taphonomic);
ginglymoidy of metatarsal II (present in DNHM D2945/6). Additionally, they added
several codings- dentary symphysis dorsally concave; dorsal centra with deep
lateral fossae (as in DNHM D2945/6); gastralia present (as noted by Zhou and
Zhang); lateral coracoid margin not convex (as in DNHM D2945/6;
Chiappe et al. suggest the holotype is too poorly preserved to code); scapula
subequal or longer than humerus (shorter in DNHM D2945/6); intermetacarpal process
absent or present as a scar (process present in DNHM D2945/6); pubic boot absent
(as noted by Zhou and Zhang, though DNHM D2945/6 has a pubic boot). Unfortunately,
the photo of the specimen is small and often makes independant confirmation
of states impossible.
References- Zhou and Zhang, 2005. Discovery of an ornithurine bird and
its implication for Early Cretaceous avian radiation. Proceedings of the National
Academy of Sciences. 102(52), 18998-19002.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
Nesbitt, Turner, Spaulding, Conrad and Norell, 2009. The theropod furcula. Journal
of Morphology. 270, 856-879.
O’Connor, Gao and Chiappe, 2010. A new ornithuromorph (Aves: Ornithothoraces)
bird from the Jehol Group indicative of higher-level diversity. Journal of Vertebrate
Paleontology. 30(2), 311-321.
Li, Zhou and Clarke, 2011. A reevaluation of the relationships among basal ornithurine
birds from China and new information on the anatomy of Hongshanornis longicresta.
Journal of Vertebrate Paleontology. Program and Abstracts 2011, 144.
Zheng, Martin, Zhou, Burnham, Zhang and Miao, 2011. Fossil evidence of avian
crops from the Early Cretaceous of China. Proceedings of the National Academy
of Sciences of the United States of America. 108, 15904-15907.
Chiappe, Zhao, O'Connor, Gao, Wang, Habib, Marugan-Lobon, Meng and Cheng, 2014.
A new specimen of the Early Cretaceous bird Hongshanornis longicresta:
Insights into the aerodynamics and diet of a basal ornithuromorph. PeerJ. 2,e234.
Wang, Zheng, O'Connor, Lloyd, Wang, Wang, Zhang and Zhou, 2015. The oldest record
of Ornithuromorpha from the Early Cretaceous of China. Nature Communications.
6:6987.
Khinganornis Wang, Cau, Kundr�t, Chiappe, Ji, Wang, Li and Wu, 2020 online
K. hulunbuirensis Wang, Cau, Kundr�t, Chiappe, Ji, Wang, Li and Wu, 2020 online
Early Aptian, Early Cretaceous
Pigeon Hill, Longjiang Formation, Inner Mongolia, China
Holotype- (SGM-AVE-2017001)
(adult) skull (46 mm), sclerotic plates?, mandibles, nine cervical
vertebrae,
seven dorsal vertebrae, dorsal ribs, uncinate processes, gastralia,
first-seventh caudal vertebrae, scapulae (~43 mm), coracoids (27 mm),
furcula, partial
sternum, sternal ribs, humeri (52 mm), radii (48 mm), ulna (~49 mm),
carpometacarpi (mcII 24, mcIII 24 mm), phalanges I-1 (12 mm), manual
unguals I (5 mm), phalanx II-1 (12 mm), phalanx II-2 (12 mm), manual
ungual II (5 mm), phalanx III-1 (8 mm), phalanx III-2, ilia, pubes (45
mm), ischia, femora (~37 mm), tibiotarsi (60 mm), fibula, metatarsals I
(5 mm), phalanges I-1 (8 mm), pedal unguals I (5 mm), tarsometatarsi
(31 mm; mtII 28 mm), phalanges II-1 (11 mm), phalanges II-2 (9 mm),
pedal unguals II (6 mm), phalanges III-1 (12 mm), phalanges III-2 (9
mm), phalanges III-3 (8 mm), pedal unguals III (6 mm), phalanges IV-1
(8 mm), phalanges IV-2 (7 mm), phalanges IV-3 (6 mm), phalanges IV-4 (6
mm), pedal unguals IV (4 mm)
Diagnosis- (after Wang et al.,
2020 online) premaxillary teeth present; dentary alveoli developed
along the whole oral margin; low-crowned, blunt teeth with
unconstricted crown-root transition; manual digit III-1 67% length of
manual digit II-1; preacetabular process subequal in length to
postacetabular process; postacetabular process slightly curved
posteroventrally; pubic shaft straight along the proximal 67% of length
and then curved posterodorsally; pubic boot expanded posterodorsally;
metatarsals II and IV much narrower than metatarsal III at mid-shaft;
pedal digit III most robust; pedal unguals II-IV ventrally straight.
Other diagnoses- Based on their
figure 2, the proximal edge of the tarsometatarsus does not appear to
be "sloped laterally" in the right pes, while the left pes is in side
view.
Comments- Likely discovered in 2017 based on its specimen number. Wang et al. recovered this as sister to Iteravis+Changzuiornis, with this group in turn sister to Gansus plus ornithuromorphs, using a reduced subset of Cau's megamatrix.
Reference- Wang, Cau, Kundr�t,
Chiappe, Ji, Wang, Li and Wu, 2021 (2020 online). A new advanced
ornithuromorph bird from Inner Mongolia documents the northernmost
geographic distribution of the Jehol paleornithofauna in China.
Historical Biology. 33(9), 1705-1717.
Longicrusavis O'Connor, Gao and
Chiappe, 2010
L. houi O'Connor, Gao and Chiappe, 2010
Early Aptian, Early Cretaceous
Lingyuan, Dawangzhangzi Beds of Yixian Formation, Liaoning, China
Holotype- (PKUP V1069) (89 g) skull (30.7 mm), mandibles, hyoid, seven cervical
vertebrae, two anterior dorsal vertebrae, two dorsal vertebrae, several dorsal
vertebrae, dorsal ribs, synsacrum, incomplete scapulae (23.1 mm), coracoids
(12.7 mm), incomplete furcula (~12.7 mm), partial sternum, humeri (26 mm), radii
(24 mm), ulnae (25 mm), scapholunare, pisiforms, carpometacarpi (one incomplete; 13.1
mm, mcI ~2.7 mm, mcII 11.5 mm, mcIII 11.1 mm), phalanx I-1 (6.9 mm), manual
ungual I (4.3 mm), phalanges II-1 (7 mm), phalanges II-2 (7.3 mm), manual unguals
II (3.4 mm), phalanges III-1 (3.2 mm), phalanges III-2 (0.8 mm), incomplete
ilium, incomplete pubes (~31 mm), ischia, femora (24.3 mm), tibiotarsi (37.6
mm), fibulae (~16.6 mm), metatarsal I (4 mm), phalanx I-1 (4.1 mm), pedal ungual
I (3.3 mm), tarsometatarsi (one incomplete; 21.5 mm, mtII 19.2, mtIII 21 mm,
mtIV 19.6 mm), phalanx II-1 (6.3 mm), phalanx II-2 (5.4 mm), pedal ungual II
(3.3 mm), phalanx III-1 (6.8 mm), phalanx III-2 (5.7 mm), phalanx III-3 (5.1
mm), pedal ungual III, phalanx IV-1 (~4 mm), phalanx IV-2 (4.1 mm), phalanx
IV-3 (3.7 mm), phalanx IV-4 (3.8 mm), pedal ungual IV (3 mm), body feathers,
remiges
Diagnosis- (after O'Connor et al., 2010) robust beak (relative to Hongshanornis);
posteromedial sternal process absent; dorsal supracondylar process present on
distal humerus; lateral cnemial crest hooked; second and fourth metatarsals
subequal in length.
Comments- This taxon is a hongshanornithid in O'Connor et al.'s (2009,
2010) trees, but this is problematic as noted in the comments under Hongshanornithidae.
References- O'Connor, Wang, Chiappe, Gao, Meng, Cheng and Liu, 2009.
Phylogenetic support for a specialized clade of Cretaceous enantiornithine birds
with information from a new species. Journal of Vertebrate Paleontology. 29(1),
188-204.
O’Connor, Gao and Chiappe, 2010. A new ornithuromorph (Aves: Ornithothoraces)
bird from the Jehol Group indicative of higher-level diversity. Journal of Vertebrate
Paleontology. 30(2), 311-321.
Mystiornithiformes Kurochkin, Zelenkov, Averianov and Leshchinskiy, 2011
= "Mystiornithiformes" Kurochkin, Zelenkov, Averianov and Leshchinskiy,
2010 online
Mystiornithidae Kurochkin, Zelenkov, Averianov and Leshchinskiy, 2011
= "Mystiornithidae" Kurochkin, Zelenkov, Averianov and Leshchinskiy,
2010 online
Mystiornis Kurochkin, Zelenkov,
Averianov and Leshchinskiy, 2011
= "Mystiornis" Kurochkin, Zelenkov, Averianov and Leshchinskiy, 2010
online
M. cyrili Kurochkin, Zelenkov, Averianov and Leshchinskiy, 2011
= "Mystiornis cyrili" Kurochkin, Zelenkov, Averianov and Leshchinskiy,
2010 online
Barremian-Aptian, Early Cretaceous
Shestakovo Formation, Russia
Holotype- (PM TSU 16/5-45) tarsometatarsus (26.4 mm; II 21.4, III 26.1,
IV 25.8 mm)
Diagnosis- (after Kurochkin et al., 2011) central proximal articular
facet on tarsometatarsus; canal in lateral extensor sulcus opening in distal
vascular foramen; metarsal II does not reach distal vascular foramen.
Other diagnoses- Kurochkin et al. (2011) listed numerous characters in
their diagnosis of Mystiornithiformes, but among them, coplanar metatarsals
and an absent proximodorsal fossa are primitive for theropods; dorsally ridged
metatarsals are also present in avisaurids; distally fused metatarsals are also
present in Avisaurus gloriae and Vorona.
Kurochkin et al also listed many supposedly diagnostic characters of Mystiornithidae
and Mystiornis. Of these, metatarsal II is often the shortest of II-IV
in theropods; trochlea often have acutely angled sagittal planes; dorsally concave
metatarsal shafts, an anteriorly angled proximal surface of metatarsal II, extremely
dorsoventrally flattened trochlea II and a ventrally flat metatarsal III are
also present in avisaurids; the proximal surface of metatarsal II is not positioned
more distally than those of III and IV, nor is the ventral surface of metatarsal
III projected noticably compared to metatarsal II.
Comments- The holotype was discovered in 2000 and announced by Kurochkin
et al. (2009). The description was first posted online in December 2010 before
being officially published in March 2011. While Kurochkin et al. placed the
taxon in its own order and family, it is not as distinctive as their paper would
suggest. They included it in a version of O'Connor et al.'s (2009) matrix, which
resulted in an basal avialan clade of Mystiornis, Avisaurus,
Vorona and Mei. The other newly added taxon, Anchiornis,
is in a polytomy with the aforementioned clade and avebrevicaudans.
This suggests a systematic coding error by the authors for their added taxa,
which I have not yet confirmed via examination. When Mystiornis, Avisaurus
and Vorona are coded for that matrix, the latter two fall out in their
normal positions (derived enantiornithine and basal euornithine), while Mystiornis
is an ornithothoracine outside of Longipterygidae and Hongshanornis+Aves.
Indeed, Cau's (2011, online) unpublished analysis places Mystiornis as
an avisaurid enantiornithine.
References- Kurochkin, Averianov, Leshchinskiy and Zelenkov, 2009. A
new bird from the Early Cretaceous of Western Siberia. Journal of Vertebrate
Paleontology. 29(3), 130A-131A.
Cau, 2011 online. http://theropoda.blogspot.com/2011/05/lenigmatico-o-forse-no-mystiornis.html
Kurochkin, Zelenkov, Averianov and Leshchinskiy, 2011. A new taxon of birds
(Aves) from the Early Cretaceous of Western Siberia, Russia. Journal of Systematic
Palaeontology. 9(1), 109-117.
Belluornis Wang,
Zhou and Zhou, 2016b
= Bellulia Wang, Zhou and Zhou, 2016a (preoccupied Fibiger, 2008)
= "Bellulornis" IVPP, online 2016
B. rectusunguis (Wang, Zhou and Zhou, 2016a) Wang, Zhou and Zhou,
2016b
= Bellulia rectusunguis Wang, Zhou and Zhou, 2016a
= "Belluornis" rectusunguis (Wang, Zhou and Zhou, 2016a) IVPP,
online 2016
Early Albian, Early Cretaceous
Jiufotang Formation, Liaoning, China
Holotype- (IVPP V17970) two posterior cervical vertebrae, several dorsal
vertebrae, six dorsal ribs, synsacrum, three caudal vertebrae, pygostyle (11.2 mm), two
chevrons, scapulae (one incomplete; ~60.4 mm), coracoids (one incomplete; 29.7
mm), incomplete furcula, incomplete sternum two sternal ribs, humeri (one incomplete;
69.6 mm), radii (one partial; 74.3 mm), ulnae (78.2 mm), scapholunare, pisiforms, carpometacarpi
(one incomplete; 39.3 mm, mcI 7.6 mm), phalanges I-1 (17 mm), manual unguals
I (8.3 mm), phalanges II-1 (16.5 mm), phalanges II-2 (15.5 mm), manual unguals
II (10.9 mm), phalanges III-1 (10.1 mm), pelvis, pubis (~49.5 mm), femora (one
incomplete; 53 mm), incomplete tibiotarsi (66 mm), fibula, metatarsals I, pedal
ungual I (3.8 mm), tarsometatarsi (34.9 mm), phalanx II-1 (11.3 mm), phalanges
II-2 (8.3 mm), pedal unguals II (6.4 mm), phalanx III-1 (9.8 mm), phalanx III-2
(8.2 mm), phalanges III-3 (7.1 mm), pedal unguals III (7 mm), phalanx IV-1 (8.5
mm), phalanges IV-2 (5.5 mm), phalanges IV-3 (4.9 mm), phalanges IV-4 (4.5 mm),
pedal unguals IV (5.2 mm), 12+ gastroliths (3.5-8.8 mm), remiges, retrices
Diagnosis- (after Wang et al., 2016a) large hypocleidium (also in Parahongshanornis and Schizoouridae); long posterolateral sternal processes
with fan-shaped distal expansion (also in Archaeornithura and Jiuquanornis); 113 degree angle between sternal coracoidal sulci
(also in Archaeornithura and Schizooura); intermembral index (humerus
+ ulna + carpometacarpus / femur + tibiotarsus + tarsometatarsus) 1.21; manual
unguals nearly straight; proximal ends of ends of metatarsals II-IV coplanar
(also in Schizooura and Jianchangornis); metatarsal IV robust;
pedal ungual I reduced (also in Schizooura).
Other diagnoses- Wang et al.
(2016a) included other characters in their diagnosis. The furcula only
appears V-shaped due to the hypocleidium, but has medially curved arms.
Comments- The genus Bellulia is preoccupied by a micronoctuid
moth (Fibiger, 2008), so the bird was renamed Bellulornis by Wang et
al. (2016b). The latter name was first used in an IVPP press release, so was
an nomen nudum for a time. Wang et al. (2016a) added the taxon to O'Connor's
bird matrix and found it to be a euornithine sensu Sereno more derived than
only Archaeorhynchus and Jianchangornis, in a clade with Schizooura.
References- Fibiger, 2008. Revision of the Micronoctuidae (Lepidoptera:
Noctuoidea). Part 2, Taxonomy of the Belluliinae, Magninae and Parachrostiinae.
Zootaxa. 1867, 1-136.
IVPP, online 2016. http://english.ivpp.cas.cn/rh/rp/201601/t20160111_158608.html
Wang, Zhou and Zhou, 2016a. A new basal ornithuromorph bird (Aves: Ornithothoraces)
from the Early Cretaceous of China with implication for morphology of early
Ornithuromorpha. Zoological Journal of the Linnean Society. 176(1), 207-223.
Wang, Zhou and Zhou, 2016b. Corrigendum. Renaming of Bellulia Wang, Zhou
& Zhou, 2016. Zoological Journal of the Linnean Society. 177(3), 695.
Wang, O'Connor, Pan and Zhou, 2017. A bizarre Early Cretaceous
enantiornithine bird with unique crural feathers and an ornithuromorph
plough-shaped pygostyle. Nature Communications. 8:14141.
Xinghaiornis Wang, Chiappe, Teng
and Ji, 2013
X. lini Wang, Chiappe, Teng and Ji, 2013
Barremian-Aptian, Early Cretaceous
Yixian Formation, Liaoning, China
Holotype- (XHPM 1121) skull (81 mm), mandible, cervical vertebrae, dorsal
vertebrae, dorsal ribs, synsacrum, caudal vertebrae, scapulae (~62 mm), coracoid,
furcula, sternum, humeri (~75 mm), radii, ulnae, carpometacarpus, phalanx II-1,
phalanx II-2, manual ungual II, ilia, femora (~52 mm), tibiotarsi (~72 mm),
fibula, metatarsal I, phalanx I-1, tarsometatarsi (~34 mm), pedal phalanges,
pedal unguals, body feathers, remiges
Diagnosis- (after Wang et al., 2013) long and slim rostrum; toothless
beak; dentary with elongated grooves; slender, Y-shaped furcula; large, robust
deltopectoral crest; (humerus+radius)/(femur+tibiotarsus) ratio ~1.2; metatarsal
I articulates close to midshaft of metatarsal II; trochlea of metatarsal I much
more proximally located than trochlea II-IV.
Comments- Wang et al. (2013) believe this taxon may be close to the base
of Ornithothoraces based on the combination of classic enantiornithine (long
hypocleidium; metacarpal III extends distal to II) and euornithine (dome/ball-shaped
humeral head; proximally placed pedal digit I; small, weakly curved pedal unguals)
characters. Yet the description is so brief and the photo quality so poor that
any meaningful analysis is impossible.
Reference- Wang, Chiappe, Teng and Ji, 2013. Xinghaiornis lini
(Aves: Ornithothoraces) from the Early Cretaceous of Liaoning: An example of
evolutionary mosaic in early birds. Acta Geologica Sinica. 87(3), 686-689.
Mengciusornis Wang, O'Connor, Zhou and Zhou, 2019 online
M. dentatus Wang, O'Connor, Zhou and Zhou, 2019 online
Early Albian, Early Cretaceous
Lamadong, Jiufotang Formation, Liaoning, China
Holotype- (IVPP V26275) skull (59.52 mm), mandibles, hyoid, several
cervical vertebrae, several dorsal vertebrae, dorsal ribs, gastralia,
synsacrum (27.31 mm), caudal vertebra, scapulae (~61.91 mm), coracoids
(30.34 mm), incomplete furcula, humeri (65.90 mm), radii (61.00 mm),
ulnae (64.85 mm), scapholunare, pisiform, carpometacarpi (32.19 mm; mcI
7.27 mm), phalanges I-1 (13.47 mm), manual ungual I (3.81 mm),
phalanges II-1 (14.55 mm), phalanges II-2 (14.85 mm), manual ungual II,
phalanx III-1 (6.70 mm), ilia, pubes (~51.31 mm), ischia, femora (47.57
mm), tibiotarsi (60.74 mm), fibula, metatarsals I, phalanges I-1 (4.9
mm), pedal unguals I (3.65 mm), tarsometatarsi (34.25 mm), phalanges
II-1 (8.93 mm; one proximal), phalanx II-2 (6.81 mm), pedal ungual II
(5.41 mm), phalanges III-1 (8.83 mm), phalanges III-2 (6.94 mm),
phalanges III-3 (6.34 mm; one proximal), pedal unguals III (5.99 mm),
phalanx IV-1 (5.98 mm), phalanges IV-2 (5.70 mm), phalanges IV-3 (4.19
mm), phalanges IV-4 (3.63 mm), pedal unguals IV (4.46 mm), remiges
Diagnosis- (after Wang et al.,
2020) teeth only found in premaxillae; scapula over 90% of humeral
length; scapula with ventrally hooked acromion; coracoid with small
procoracoid process; coracoid lacking supracoracoidal nerve foramen;
furcula with relatively elongate hypocleidium that measures
approximately 31% length of ramus; elongate forelimb - (humerus/ulna)
120% the length of the hind limb (femur/tibiotarsus); ulna shorter than
humerus.
Comments- Discovered prior to August 2019. The article describing Mengciusornis was published online on November 11 9019 but not published physically until 2020.
Wang et al. (2020) added it to O'Connor's avialan analysis to recover it as a basal euornithine sister to Schizooura, a clade they named Schizoouridae.
Reference- Wang, O'Connor, Zhou
and Zhou, 2020 (online 2019). New toothed Early Cretaceous
ornithuromorph bird reveals intraclade diversity in pattern of tooth
loss. Journal of Systematic Palaeontology. 18(8), 631-645.
Changmaornis Wang, O'Connor, Li
and You, 2013
C. houi Wang, O'Connor, Li and You, 2013
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Holotype- (GSGM-08-CM-002) two dorsal vertebrae, dorsal rib, synsacrum,
partial ilia, incomplete pubis, incomplete ischium, distal tibiotarsus, metatarsal
I, phalanx I-1 (7.4 mm), pedal ungual I (3.9 mm), tarsometatarsus (36.9 mm),
phalanx II-1 (10 mm), phalanx II-2 (9.9 mm), pedal ungual II (4.8 mm), phalanx
III-1 (11.4 mm), phalanx III-2 (7.4 mm), phalanx III-3 (7.3 mm), pedal ungual
III (4.2 mm), phalanx IV-1 (8.5 mm), phalanx IV-2 (6.3 mm), phalanx IV-3 (4.9
mm), phalanx IV-4 (4.9 mm), pedal ungual IV (3.6 mm)
Diagnosis- (after Wang et al., 2013) synsacrum composed of at least 11
sacral vertebrae with elongate distal transverse processes; ischium with dorsal
process; distal half of the pubis compressed mediolaterally; metatarsal I J-shaped;
distal margin of metatarsal II trochlea does not reach proximal margin of metatarsal
III trochlea; pedal digit III longest in foot; ratio of pedal digit III to tibiotarsus
0.82; robust and blunt pedal unguals with poorly developed flexor tubercles.
Comments- Wang et al. entered this into O'Connor's matrix and found it
to be a basal ornithomorph in large polytomy with taxa less derived than Ichthyornis
but more derived than Patagopteryx.
Reference- Wang, O'Connor, Li and You, 2013. Previously unrecognized
ornithuromorph bird diversity in the Early Cretaceous Changma Basin, Gansu Province,
Northwestern China. PLoS ONE. 8(10), e77693.
Apsaraviformes Livezey and Zusi, 2007
Definition- (Apsaravis ukhaana <- Passer domesticus) (Martyniuk,
2012)
= "Apsaravidae" Livezey and Zusi, 2007
= Palintropiformes Longrich, Tokaryk and Field, 2011
Definition- (Palintropus retusus <- Hesperornis regalis, Ichthyornis
dispar, Passer domesticus) (modified from Longrich et al., 2011)
= Apsaraves Zelenkov in Zelenkov and Kurochkin, 2015
= Apsaravidae Zelenkov in Zelenkov and Kurochkin, 2015
Comments-
Livezey and Zusi (2007) named Apsaraviformes and "Apsaravidae" as
monotypic and redundant taxa including only Apsaravis.
"Apsaravidae" is a nomen nudum as it was only included in a table,
without definition or diagnosis (ICZN Article 13.1.1). Martyniuk
defined Apsaraviformes. Apsaraves was created by Zelenkov in a
book chapter by Zelenkov and Kurochkin (2015) as a clade including
Apsaraviformes which in turn included Apsaravis and Schizooura. He also named Apsaravidae, this time officially due to the inclusion of a diagnosis.
Longrich et al. (2011) erected Palintropiformes for Palintropus and Apsaravis,
which they found formed a clade based on a version of Clarke's matrix.
References-
Livezey and Zusi, 2007. Higher-order phylogeny of modern birds (Theropoda, Aves:
Neornithes) based on comparative anatomy. II. Analysis and discussion. Zoological
Journal of the Linnean Society. 149 (1), 1-95.
Longrich, Tokaryk and Field, 2011. Mass extinction of birds at the Cretaceous-Paleogene
(K–Pg) boundary. Proceedings of the National Academy of Sciences. 108(37),
15253-15257.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Zelenkov and Kurochkin, 2015. Class Aves. In Kurochkin, Lopatin and
Zelenkov (eds.). Fossil vertebrates of Russia and adjacent countries.
Part 3. Fossil Reptiles and Birds. GEOS. 86-290.
Apsaravis Norell and Clarke,
2001
A. ukhaana Norell and Clarke, 2001
Late Campanian, Late Cretaceous
Ukhaa Tolgod, Djadokhta Formation, Mongolia
Holotype- (IGM 100/1017) (180 g) partial jugal, posterior skull, sclerotic
ring, incomplete mandible, twelve cervical vertebrae, six dorsal vertebrae (4.5
mm), fragmentary dorsal ribs, synsacrum (28.6 mm), five caudal vertebrae (2.04
mm), partial pygostyle, scapulae (~52.5 mm), coracoids (29.25 mm), anterior
sternum, humeri (48.43 mm), radii (43.11 mm), ulnae (45.69 mm), scapholunare, pisiform,
incomplete carpometacarpi, phalanx II-1 (~9.62 mm), ilia (31.5 mm), pubes (one
proximal; 30.14 mm), ischia (30.14 mm), proximal femora (~40.9 mm), distal tibiotarsi,
tarsometatarsi (28.7 mm), phalanges II-1, phalanges II-2, pedal ungual II, phalanges
III-1 (one proximal), phalanx III-2, phalanx III-3, pedal unguals III, phalanges
IV-1, phalanges IV-2, phalanx IV-3, pedal ungual IV, several pedal phalanges,
ossified tarsometatarsal tendon
Diagnosis- (after Norell and Clarke, 2001) dentary forked posteriorly
(unknown in Ambiortus; also in Yixianornis+Songlingornis);
strong tubercle on the proximal posterior surface of the humerus directly distal
to the humeral head; distal humerus strongly flared and anteroposteriorly compressed
(unknown in Ambiortus); humeral distal condyles strap-like (unknown in
Ambiortus); dorsal condyle of humerus transversely oriented (unknown
in Ambiortus); ventral condyle of humerus strongly projected distally
(unknown in Ambiortus); enlarged lateral ridge on the femur (unknown
in Ambiortus; also in hesperornithines); medial tibiotarsal condyle <60%
the width of the lateral condyle (unknown in Ambiortus; also in Longicrusavis);
tibiotarsal condyles do not slope towards center in distal view (unknown in
Ambiortus; also in Longicrusavis); tibiotarsal intercondylar groove
less than 30% as wide as distal condyles (unknown in Ambiortus); well-projected
wings of the sulcus cartilaginis tibialis on the posterodistal tibiotarsus.
(after Clarke and Norell, 2002) laterally hooked acromion process (also in Yanornis);
metatarsal II non-ginglymoid (unknown in Ambiortus; also in some hesperornithines
and Yanornis).
Other diagnoses- Norell and Clarke (2001) also use the scapular blade
which does not expand at midlength in their diagnosis, though Clarke and Norell
(2002) later exclude it from their diagnosis and analysis, citing difficulty
in defining it objectively. In any case, such a scapula is also present in songlingornithids
and Hesperornis, making its presence in Patagopteryx, Ichthyornis
and Ambiortus equally likely to be convergent as it is to be developed
basally in Euornithes and lost by Apsaravis. Norell and Clarke note
a supposedly apomorphic hypertrophied trochanteric crest on the femur, which
is also described and photographed by Clarke and Norell. However, this structure
is a posterolaterally projected crest distal to the femoral head, which is unlike
trochanteric crests but like the lateral ridge of more basal maniraptorans which
is derived from the trochanteric shelf. Whether the lateral ridge's size is
apomorphic is uncertain, as hesperornithines have an even larger bulge and Patagopteryx
and Gansus have small tubercles. Another less developed vertical ridge
is present posterior to this, which could also be homologized to the trochanteric
shelf. However, topologically, this would be equivalent to the posterior trochanter.
Clarke and Norell (2002) also add a fused dentary symphysis to their diagnosis,
but that is optimized as a carinate character here.
Comments-
The holotype was discovered in 1998 and described briefly in 2001 by
Norell and Clarke, then in detail the next year (Clarke and Norell,
2002). It was originally placed as the sister taxon to Carinatae, but
Clarke (2002) and Clarke and Norell (2002) found it to be the sister
group of Ornithurae instead. This result has been found in further
permutations of Clarke's matrix as well (e.g. You et al., 2006;
O'Connor et al., 2009).
References- Clarke and Norell, 2001. Fossils and avian evolution. Nature.
414, 508.
Feduccia, 2001. Fossils and avian evolution. Nature. 414, 507-508.
Norell and Clarke, 2001. Fossil that fills a critical gap in avian evolution.
Nature. 409, 181-184.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke and Norell, 2002. The morphology and phylogenetic position of Apsaravis
ukhaana from the Late Cretaceous of Mongolia. American Museum Novitates.
3387, 1-46.
You, Lamanna, Harris, Chiappe, O'Connor, Ji, Lu, Yuan, Li, Zhang, Lacovara,
Dodson and Ji, 2006. A nearly modern amphibious bird from the Early Cretaceous
of Northwestern China. Science. 312, 1640-1643.
O'Conner, Wang, Chiappe, Gao, Meng, Cheng and Liu, 2009. Phylogenetic support
for a specialized clade of Cretaceous enantiornithine birds with information
from a new species. Journal of Vertebrate Paleontology. 29(1), 188-204.
Palintropus Brodkorb, 1970
Diagnosis- (after Longrich, 2009) acrocoracoid process massive and knob-like
(also in Gansus and Ichthyornis); edge of humeral articular facet
with a prominent lip in ventral view (also in Yixianornis); prominent
scar inside supracoracoid sulcus (unknown in most non-avian euornithines).
Other diagnoses- Marsh (1892) first noted the absent procoracoid process
as diagnostic, but this is shared with Apsaravis.
Here I interpret the very large, centrally and distally placed supracoracoid
foramen noted as diagnostic by Hope (2002) as the proximal edge of a dorsal
coracoid fossa as in Apsaravis. This same feature was described as "prominent
dorsal groove in coracoid shaft" by Longrich (2009).
Longrich also included the supracoracoid foramen opening into a medial groove
of the coracoid shaft, which is shared with Apsaravis.
Comments- Marsh (1892) originally included retusus in Cimolopteryx,
as C. retusa. Shufeldt (1915) noted it was not referrable to Cimolopteryx
and probably not even closely related, though he felt it was too fragmentary
for further evaluation. Brodkorb (1963) first removed it to Apatornis,
which he viewed as an ichthyornithine. He then (1970) placed it in a new genus
Palintropus, which he believed was a cimolopterygid charadriiform.
Palintropus a galliform? Hope (2002) questionably referred this
taxon to Galliformes. This was based on the reduced procoracoid process, coracoid
facet for scapula placed entirely distal to glenoid. Several other characters
were listed in Hope's Galliformes diagnosis as being reasons why she placed
"specimens below" (consisting solely of Palintropus) in that
order, but are eithjer undescribed (coracoid neck with stout and triangular
cross section) or unknown (elongate coracoid shaft; narrow sternal end of coracoid;
rudimentary lateral process) in that genus. She also noted the acrocoracoid
was similar in size to galliforms (larger than tinamiforms, smaller than anseriforms
and most neoavians), the absence of a pneumatic foramen is unlike tinamiforms,
and the laterally positioned coracoid tubercle which merges with the glenoid
is similar to galliforms. However, the procoracoid process is also absent in
Patagopteryx and (as noted by Longrich, 2009) Apsaravis, while
it is still present though reduced in basal galliforms like Paraortygoides,
Paraortyx and Ameripodius. I also note Apsaravis has a
coracoid facet placed distal to the glenoid. Lack of coracoid pneumatization
is present in all non-avians (except perhaps Jixiangornis and Jianchangornis).
The laterally positioned coracoid tubercle that merges with the glenoid is also
found in galliforms, tinamiforms, Lithornis, Patagopteryx, Yixianornis,
Jianchangornis, Ichthyornis and Ambiortus, so seems symplesiomorphic
for Aves. Gansus and Ichthyornis also have moderate sized acrocoracoid
processes.
Hope referred it questionably to the basal galliform family Quercymegapodiidae
based on the large free lateral flange on the coracoid glenoid, further reduced
procoracoid process (only with Quercymegapodius and not Ameripodius),
and scar within the supracoracoid sulcus (only verified in Ameripodius).
Also she correctly noticed the deep cup-like scapular facet is unlike crown
galliforms. Apsaravis, Ichthyornis, Gansus, Yixianornis,
Patagopteryx and Archaeorhynchus also have a large lateral flange
on the coracoid glenoid. Almost all non-avian euornithines also have scapular
cotyla which are deeper than those of crown galliforms. The texture of the supracoracoid
sulcus is generally indeterminable in non-avian euornithines, even when they
expose the sulcus as in Yixianornis. Hope, Mayr (2009) and Longrich all
noted that it was unlike Tertiary Galliformes in having a supracoracoid foramen,
and Longrich stated it differed further in lacking a strongly hooked acrocoracoid.
Thus Palintropus does not share any characters with galliforms not seen
in Apsaravis except for the larger acrocoracoid (which is also seen in
some non-avian euornithines). As Palintropus has some characters which
exclude it from Galliformes, and the only character shared with a quercymegapodiid
(the supracoracoid sulcus scar) is indeterminate in Apsaravis and most
other non-avian euornithines, it is near certainly not a member of Quercymegapodiidae.
Palintropus related to Apsaravis? Longrich (2009) suggested
Palintropus was related to Apsaravis based on the absent procoracoid
process and medial supracoracoid groove. They also seem to share a deep dorsal
fossa in the coracoid. While these characters are also shared with most enantiornithines,
the scapulocoracoid articulation is unlike that clade. The referred dorsal and
femur also lack enantiornithine synapomorphies (e.g. they have anteriorly placed
parapophyses and no posterior trochanter). Longrich et al. (2011) included Palintropus
in a version of Clarke's matrix where it claded with Apsaravis, but did
not include basal galliforms that could test Hope's hypothesis.
References- Marsh, 1892. Notes on Mesozoic vertebrate fossils. American
Journal of Science. 55, 171-175.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions
of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Brodkorb, 1970. The generic position of a Cretaceous bird. Quarterly Journal
of the Florida Academy of Science. 32(3), 239-240.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Mayr, 2009. Paleogene Fossil Birds. Springer-Verlag, Heidelberg & New York.
262 pp.
Longrich, Tokaryk and Field, 2011. Mass extinction of birds at the Cretaceous-Paleogene
(K–Pg) boundary. Proceedings of the National Academy of Sciences. 108(37),
15253-15257.
P. retusus (Marsh, 1892) Brodkorb,
1970
= Cimolopteryx retusa Marsh, 1892
= Apatornis retusus (Marsh, 1892) Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (YPM 513) proximal coracoid
Diagnosis- (after Longrich, 2009) smaller than both Campanian species;
lacks kink in the ridge connecting the humeral articular facet and acrocoracoid;
acrocoracoid process shorter and more expanded; humeral articular facet broader
anteriorly than posteriorly; dorsal groove extends to level of scapular cotyle.
Comments- The holotype was discovered in 1980.
References- Marsh, 1892. Notes on Mesozoic vertebrate fossils. American
Journal of Science. 55, 171-175.
Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. in Sibley (ed.).
Proceedings of the XIII International Ornithological Congress. 50-70.
Brodkorb, 1970. The generic position of a Cretaceous bird. Quarterly Journal
of the Florida Academy of Science. 32(3), 239-240.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
P. sp. nov. (Hope, 2002)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1986.036.0126) proximal coracoid (Hope, 2002)
?(TMP 1989.081.0012) dorsal vertebra (Longrich, 2009)
?(TMP 2001.012.0150) distal femur (Longrich, 2009)
Diagnosis- (after Longrich, 2009) over twice as large as P. retusus,
a third larger than the other Campanian species; kink in the ridge connecting
the humeral articular facet and acrocoracoid; acrocoracoid process shorter and
more expanded; humeral articular facet broader anteriorly than posteriorly;
dorsal groove extends to level of scapular cotyle.
Comments- Hope (2002) referred TMP 1986.036.0126 to a new species of Palintropus,
along with TMP 1986.146.0011, 1988.116.0001 and five other TMP specimens. She noted
some of these specimens were smaller, so might belong to another species, or
that Palintropus may have been sexually dimorphic. Longrich referred TMP 1986.036.0126 to his Palintropus species A, along with a dorsal vertebra
and femur based on their size.
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe
and Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 339-388.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
P. sp. nov. (Longrich, 2009)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1983.036.0070) coracoid fragment (Longrich, 2009)
(TMP 1988.116.0001) proximal coracoid (Hope, 2002)
?(TMP 1989.050.0053) dorsal vertebra, partial synsacrum (Longrich, 2009)
(TMP 1992.053.0003) coracoid fragment (Longrich, 2009)
?(TMP 1996.012.0336) femur (Longrich, 2009)
(TMP 2005.012.0190) partial coracoid (Longrich, 2009)
Late Campanian, Late Cretaceous
Foremost Formation, Alberta, Canada
?(TMP 1986.146.0011) proximal scapula (Hope, 2002)
Diagnosis- (after Longrich, 2009) intermediate in size between other
species; lacks kink in the ridge connecting the humeral articular facet and
acrocoracoid; acrocoracoid process taller and less expanded; humeral articular
facet strongly semicircular; dorsal groove does not extend to level of scapular
cotyle.
Comments- Hope (2002) referred TMP 1986.146.0011 and 1988.116.0001 to the same
undetermined Palintropus species as TMP 1986.036.0126, though she noted
the latter might belong to a different species or sex. Longrich (2009) placed
the former specimens in his new Palintropus species B, which he stated
differed markedly in morphology from P. retusus or P. species
A.
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe
and Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 339-388.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
P. sp. (Hope, 2002)
Late Campanian, Late Cretaceous
Belly River Group, Alberta, Canada
Material- (TMP coll.) three partial coracoids (Hope, 2002)
Comments- Hope (2002) referred five coracoids in the TMP collections
to her new Palintropus species, two of which are probably TMP 1983.036.0070
and 1992.053.0003 that were later mentioned by Longrich (2009) and referred to his
Palintropus species B. Whether the other three belong to P. species
A or B is unknown.
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe
and Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 339-388.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
unnamed possible apsaraviform (Longrich, 2009)
Late Campanian, Late Cretaceous
Upper Dinosaur Park Formation, Alberta, Canada
Material- (UALVP 47942; Ornithurine C) proximal coracoid
Diagnosis- (after Longrich, 2009) small size; subcircular scapular cotyle;
procoracoid process absent.
Comments- Longrich (2009) assigned this to his Ornithurae
sensu Gauthier and de Quieroz based on an anteriorly placed scapular
facet, and noted "within the Ornithurae, absence of a procoracoid
process is a derived feature shared with Palintropus and Apsaravis, suggesting that it may be related to either or both.. Agnolin (2010) suggested it was a cimolopterygid, but Mohr et al.
(2021) correctly noted it lacks his proposed characters for the family-
distally extensive procoracoid process; laterally angled glenoid; distally placed and enlarged
supracoracoid foramen (unknown as the bone is broken proximal to the foramen).
References- Longrich, 2009. An ornithurine-dominated avifauna from the
Belly River Group (Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous
Research. 30(1), 161-177.
Agnolin, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina.
Studia Geologica Salmanticensia. 46(2), 99-119.
Mohr, Acorn, Funston and Currie, 2021 (2020 online). An ornithurine bird coracoid from the Late Cretaceous of Alberta, Canada. Canadian Journal of Earth Sciences. 58(2), 134-140.
Ornithurae Haeckel, 1866
Official Definition- (Hesperornis regalis + Ichthyornis dispar + Vultur gryphus) (Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022; Registration Number 554)
Other definitions- (Passer domesticus <- Archaeopteryx lithographica)
(Sereno, online 2005; modified from Gauthier, 1986)
(Hesperornis regalis + Passer domesticus) (Turner, Makovicky and Norell, 2012; modified from Padian, Hutchinson and Holtz, 1999; modified from Chiappe, 1991)
(tail shorter than the femur and with an upturned and ploughshare-shaped compressed
pygostyle in the adult, composed of less than six segments, and shorter than
the less than eight free caudals homologous with Vultur gryphus) (Gauthier
and de Queiroz, 2001)
(Hesperornis regalis + Ichthyornis dispar + Passer domesticus)
(modified from Padian, 2004)
= Ornithurae sensu Chiappe, 1991
Definition- (Hesperornis regalis + Passer domesticus) (modified)
= Carinatae sensu Chiappe, 1995
Definition- (Ichthyornis dispar + Passer domesticus) (modified)
= Ornithurae sensu Padian, 2004
Definition- (Hesperornis regalis + Ichthyornis dispar + Passer
domesticus) (modified)
References- Haeckel, 1866.
Generelle Morphologie der Organismen: allgemeine Grundz�ge der
organischen Formen-Wissenschaft mechanisch begr�ndet durch die von
Charles Darwin reformierte Deskendenz-Theorie. G. Reimer. 574 pp.
Gauthier, 1986. Saurischian monophyly and the origin of birds. Memoirs of the Californian Academy of Sciences 8, 1-55.
Chiappe, 1991. Cretaceous avian remains from Patagonia shed new light on the early radiation of birds. Alcheringa. 15, 333-338.
Chiappe, 1995. The first 85 million years of avian evolution. Nature. 378, 349-355.
Padian, Hutchinson and Holtz, 1999. Phylogenetic definitions and nomenclature
of the major taxonomic categories of the carnivorous Dinosauria (Theropoda).
Journal of Vertebrate Paleontology. 19(1), 69-80.
Gauthier and de Quieroz, 2001. Feathered dinosaurs, flying dinosaurs, crown
dinosaurs, and the name "Aves." In Gauthier and Gall (eds.). New Perspectives
on the Origin and Early Evolution of Birds: Proceedings of the International
Symposium in Honor of John H. Ostrom. Peabody Museum of Natural History. 7-41.
Padian, 2004. Basal Avialae. In Weishampel, Dodson and Osmolska
(eds.). The Dinosauria Second Edition. University of California Press. 210-231.
Sereno, online 2005. Stem Archosauria - TaxonSearch. http://www.taxonsearch.org/dev/file_home.php
[version 1.0, 2005 November 7]
Turner, Makovicky and Norell, 2012. A review of dromaeosaurid
systematics and paravian phylogeny. Bulletin of the American Museum of Natural
History. 371, 1-206.
Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022. Forty new specimens of Ichthyornis provide unprecedented insight into the postcranial morphology of crownward stem group birds. PeerJ. 10:e13919.
Gargantuaviidae Buffetaut and Angst, 2019
Gargantuavis Buffetaut and
Le Loeuff, 1998
G. philoinos Buffetaut and Le Loeuff, 1998
Early Maastrichtian, Late Cretaceous
Bellevue, Marnes de la Maurine Formation, Aude, France
Holotype- (MDE-CE-525) synsacrum (180 mm), partial ilia
Late Campanian-Early Maastrichtian, Late Cretaceous
Combebelle site, Villespassans, Herault, France
Paratype- ?(MDE-A08) (>10 year old adult; 147 kg) incomplete femur (~334 mm)
Late Campanian-Early Maastrichtian, Late Cretaceous
Montplo-Nord, Cruzy, Herault, France
Referred- (MC-MN 431) ilial fragment (Buffetaut and Angst, 2015; described by Buffetaut and Angst, 2016b)
?..?(MC-MN 478) mid cervical vertebra (Buffetaut, 2011a; described
by Buffetaut and Angst, 2013)
?...(MC-MN 1165) synsacral fragment (Buffetaut and Angst, 2015; described by Buffetaut and Angst, 2016b)
?...(MC-MN 1335) (~57 kg) femur (235 mm) (Angst and Buffetaut, 2018; described by Buffetaut and Angst, 2019)
Late Campanian-Early Maastrichtian, Late Cretaceous
Bastide-Neuve, Fox Amphioux, Var, France
(BN
758) incomplete synsacrum, partial ilia (Buffetaut and Angst, 2015;
described by Buffetaut, Angst, Mechin and Mechin-Salessy, 2015)
(BN 763) dorsal rib fragment, incomplete synsacrum, partial ilium,
?ilial fragment (Buffetaut and Angst, 2015; described by Buffetaut,
Angst, Mechin and Mechin-Salessy, 2015)
(Mechin coll. 711) (75 kg) incomplete femur (Buffetaut, Angst, Mechin and Mechin-Salessy, 2019)
?(MDE-A07) partial synsacrum (Buffetaut, Angst, Mechin and Mechin-Salessy, 2015)
Late Campanian, Late Cretaceous
La�o, Sedano Formation, Spain
(MCNA 2583) partial synsacrum, ilial fragments (Buffetaut and Angst,
2015; described by Angst, Buffetaut, Corral and Pereda-Suberbiola, 2017)
Early Maastrichtian, Late Cretaceous
Nălaţ-Vad, Sinpetru Formation, Romania
(UBB V649) synsacrum (147 mm), incomplete ilia (Mayr, Codrea, Solomon, Bordeianu and Smith, 2020)
Diagnosis- (after Buffetaut and Le Loeuff, 1998) robust and short synsacrum;
ten synsacral vertebrae; broad pelvis; acetabulum placed at level of third and
fourth synsacral transverse processes; well-developed antitrochanter placed
posterodorsally to large acetabulum; ilia do not contact dorsally.
(after Buffetaut and Angst, 2016a) heterocoelous cervical vertebra with
remarkably narrow posterior articular surface; synsacrum markedly
arched ventrally; pelvis extensively pneumatized; robust femur with
trochanteric crest but no posterior trochanter.
(after Buffetaut and Angst, 2019) synsacrum and ilium extensively
pneumatized; lateral femoral condyle is divided into two semicondyles;
medial condye extends farther distally than lateral condyle.
Comments-
Buffetaut et al. (1995) described a synsacral fragment of a large bird,
which they left unnamed. Buffetaut and Le Loeuff (1998) later described
the holotype partial pelvis and paratype femur from different
localities as the new taxon Gargantuavis philoinos.
They referred the femur because of its similar size and large
trochanteric crest which could articulate with the holotype's
antitrochanter, but this must be regarded as provisional. While they
state the previously described synsacral fragment MDE-A07 is similar to
the middle of MDE-CE-525, they do not refer it explicitly to the taxon.
Buffetaut (2011a, b) first noted a referred completely heterocoelous
cervical vertebra, which was described by Buffetaut and Angst (2013). A
new femur MC-MN 1335 was described by Angst et al. (2019), which along
with the cervical and sacral and ilial fragments (Buffetaut and Angst,
2016b) "come from the same sedimentary layer and were found a short
distance from each other and may belong to a single individual." This
femur is smaller and at first glance very different in shape from the
paratype, but Angst et al. argue to paratype is extremely crushed and
badly reconstructed. They stated that if the two are different taxa,
MC-MN 1335 was more likely to be Gargantuavisas
it was found in the same locality as other specimens. Buffetaut
et al. (2019) describe a new femur Mechin coll. 711 from the same beds
as three other synsacra which resembles MC-MN 1335, further supporting
the referral of this morphotype to Gargantuavis. Mayr et al.
(2020) describe a new partial pelvis found in 2003 in Romania as "Gen.
et sp. indet. (cf. Elopteryx nopcsai Andrews, 1913)" although they also call it Gargantuavis multiple times in the paper. They state it is "only about 80% the size of the G. philoinos
holotype, from which it furthermore
differs in a more caudally positioned acetabulum, which is situated on
the level of the fifth synsacral vertebra, whereas it is on the level
of the fourth vertebra in G. philoinos"
and thus "certainly represents a different species." While this may be
true, Mesozoic theropod species show large varience in size and only
the holotype and Bastide-Neuve pelvises can be shown to have anteriorly
placed acetabula. If further discoveries show correlated
characteristics in certain localities, it may prove more useful to
separate Gargantuavis species.
Buffetaut and Le Loeuff (1998) placed
Gargantuavis as a non-ornithurine euornithine, closer to Patagopteryx
based on the broad pelvis but closer to ornithurines in sacral number.
Despite the large number of basal euornithines described in the last
two decades, Buffetaut's qualitative opinion has remained vague with
Buffetaut and Angst (2019) stating only "Gargantuavis philoinos
is certainly an ornithuromorph, and in all likelihood a basal
ornithurine" while assigning it a monotypic family. Mayr (2009; based
on Worthy, pers. comm.) suggested Gargantuavis was pterosaurian
based on the anteriorly placed acetabulum and contemporaneous large
azhdarchids, but Buffetaut and Le Loeuff (2011) demonstrated pterosaur
femora are highly dissimilar and that that clade generally has
posteriorly placed acetabula. Mayr et al. (2020) subsequently agreed
"azhdarchid affinities of Gargantuavis are not well founded." Most recently, Mayr et al. (2020) suggested Gargantuavis
was excluded from Ornithurae based on the unfused pelvis
(iliopubic and ilioischial articulations in UBB V649) and from
Pygostylia based on middle sacral vertebrae without transverse
expansion. While sacral expansion has yet to be incorporated into
phylogenetic analyses, a lack of pelvic fusion also seems to be present
in Enaliornis (BGS 87431).
Mayr et al. noted that the proximal femur Elopteryx "was of a similar
size to UBB V649, and we consider it well possible that the new pelvis
belongs to Elopteryx", but the latter taxon was recovered as a
non-ornithothoracine avialan by Hartman et al. (2019) and certainly
differs from both supposed Gargantuavis femora. They further argued
the basal avialan Balaur was similar in a few features (ventrally
arched sacrum, broad pelvis, large antitrochanter) although smaller
with a fused pelvis. This led them to propose the hypothesis that "Elopteryx, Balaur, and Gargantuavis
belong to a distinctive theropod clade, which was characteristic for
the Late Cretaceous European archipelago or parts thereof." Gargantuavis
has only been entered into a single published phylogenetic analysis,
that of Hartman et al. (2019) which recovered it as a
non-hesperornithoid hesperornithine (a clade which included Ichthyornis). This is unchanged after entering in the new data from MC-MN 1335 and UBB V649. Forcing it to be sister to Balaur takes 11 more steps, while forcing it to be sister to Patagopteryx
only takes 1 more step. Restricting the OTU to sacral and ilial
characters retains its position as a basal hesperornithine, and forcing
it sister to Balaur takes 6 more steps while forcing it to be sister to Elopteryx takes 3 steps but the latter moves to Hesperornithes instead of Gargantuavis
being more basal. Forcing all three genera to form an exclusive
clade is 8 steps longer, with the phylogenetic position of Balaur winning out. Considering this data, Gargantuavis is here considered to be an euornithine not particularly close to Balaur,
with the cervical and femora probably correctly referred considering
their phylogenetic characters and stratigraphical proximity at
Montplo-Nord. Elopteryx is more parsimoniously the femur of Balaur (1 step longer).
References- Buffetaut, Le Loeuff, Mechin and Mechin-Salessy, 1995. A
large French Cretaceous bird. Nature. 377, 110.
Buffetaut and Le Loeuff, 1998. A new giant ground bird from the Upper Cretaceous
of southern France. Journal of the Geological Society, London. 155(1), 1-4.
Buffetaut, 2002. Giant ground birds at the Cretaceous-Tertiary boundary: Extinction
or Survival? In Koeberl and MacLeod (eds.). Catastrophic Events and Mass Extinctions:
Inpacts and Beyond. Geological Society of America Special Paper. 356, 303-306.
Mayr, 2009. Paleogene Fossil Birds. Berlin: Springer. 262 pp.
Buffetaut, 2011a. Gargantuavis philoinos: Giant bird or giant pterosaur?
9th Annual Meeting of the European Association of Vertebrate Palaeontologists.
16-17.
Buffetaut, 2011b. Giant birds from the Late Cretaceous of southern France: An
update. 8th Romanian Symposium of Paleontology, Abstract Book. 13-14.
Buffetaut and Le Loeuff, 2010. Gargantuavis philoinos: Giant
bird or giant pterosaur? Annales de Pal�ontologie. 96(4), 135-141.
Buffetaut and Angst, 2013. New evidence of a giant bird from the Late Cretaceous
of France. Geological Magazine. 150(1), 173-176.
Chinsamy, Buffetaut, Canoville and Angst, 2014. Insight into the growth dynamics
and systematic affinities of the Late Cretaceous Gargantuavis from bone
microstructure. Naturwissenschaften. 101(5), 447-452.
Buffetaut and Angst, 2015. Twenty years of Gargantuavis philoinos: A
summing up on an enigmatic Late Cretaceous giant bird. SVPCA 2015, 24.
Buffetaut, Angst, Mechin and Mechin-Salessy, 2015. New remains of the giant bird Gargantuavis philoinos from the Late Cretaceous of Provence (south-eastern France). Palaeovertebrata. 39(2), e3.
Buffetaut and Angst, 2016a. The giant flightless bird Gargantuavis philoinos
from the Late Cretaceous of southwestern Europe: A review. New Mexico
Museum of Natural History and Science Bulletin. 71, 41-50.
Buffetaut and Angst, 2016b. Pelvic elements of the giant bird Gargantuavis from the Upper Cretaceous of Cruzy (southern France), with remarks on pneumatisation. Cretaceous
Research. 66, 171-176.
Angst, Buffetaut, Corral and Pereda-Suberbiola, 2017. First record of the Late Cretaceous giant bird Gargantuavis philoinos from the Iberian Peninsula. Annales de Pal�ontologie. 103(2), 135-139.
Angst and Buffetaut, 2018 (online 2017). Paleobiology of giant flightless birds. ISTE Press - Elsevier. 296 pp.
Buffetaut and Angst, 2019. A femur of the Late Cretaceous giant bird Gargantuavis from Cruzy (southern France) and its systematic implications. Palaeovertebrata. 42(1), e3.
Buffetaut, Angst, Mechin and Mechin-Salessy, 2019. A femur of the giant bird Gargantuavis from the Late Cretaceous of Var (south-eastern France). Carnets natures. 6, 47-52.
Buffetaut and Angst, 2020. Gargantuavis
is an insular basal ornithurine: A comment on Mayr et al., 2020, 'A
well-preserved pelvis from the Maastrichtian of Romania suggests that
the enigmatic Gargantuavis is neither an ornithurine bird nor an insular endemic'. Cretaceous Research. 112, 104438.
Mayr, Codrea, Solomon, Bordeianu and Smith, 2020 (online 2019). A
well-preserved pelvis from the Maastrichtian of Romania suggests that
the enigmatic Gargantuavis is neither an ornithurine bird nor an insular endemic. Cretaceous Research. 106, 104271.
Mayr, Codrea, Solomon, Bordeianu and Smith, 2020. Reply to comments on
"A well-preserved pelvis from the Maastrichtian of Romania suggests
that the enigmatic Gargantuavis is neither an ornithurine bird nor an insular endemic". Cretaceous Research. 112, 104465.
Zhyraornithi Nessov, 1992
Zhyraornithidae Nesov, 1984
Zhyraornis Nesov, 1984
Diagnosis- (modified from Nesov, 1984) sacral centra four through eight
extremely narrow ventrally (<30% of dorsal sacral width); well developed
lateral fossa in second sacral centrum.
Other diagnoses- Of Nesov's (1984) other characters in his diagnosis-
amphicoelous centra are symplesiomorphic for theropods; the sacrum's narrowness
is similar to other basal carinates; the neural spine crest is continuous in
most birds and is not tall in Z. logunovi; and the first sacral centrum
has lateral fossae in Ichthyornis and Guildavis as well. Nessov's
other characters are based on the questionably referred paratype dorsal (lateral
central fossae in dorsal vertebrae) and scapula (curved and projected acromion).
Kurochkin (2000) included several additional characters in his diagnosis for
the genus, but none are valid. Apatornis and many other Mesozoic birds
have ventrally concave synsacra. The anterior articular surface is not particularily
broad in Z. logunovi at least (width ~107% of height), comparable to
the subcircular surfaces described for Ichthyornis and Guildavis.
The slight anterior broadening is comparable to other basal carinates, as is
the absence of a ventral groove. Ichthyornis can also only have one sacral
with small transverse processes in front of those with large processes (in the
holotype, but not YPM 1372). Finally, the largest transverse processes (on sacrals
two and three) are also posteriorly directed in Ichthyornis.
Comments- Nesov (1984) first referred Zhyraornis to its own family
within Ichthyornithiformes (in which he included Apatornis), due to the
amphicoelous anterior articular surface and pleurocoels in the first two centra.
While the latter seems to be based on incorrect homology with YPM 1372, Nesov
was correct in his general idea. In 1992, he erected the suborder Zhyraornithi
within Ichthyornithiformes, presumably to separate Zhyraornis further
from Ichthyornis and Apatornis. Kurochkin (1995) suggested it
was an enantiornithine, based on several characters and similarity to Gobipteryx
(= Nanantius valifanovi of Kurochkin). Of the characters he lists, "flatness
and general shape" are vague, but Zhyraornis has highly convex centra
ventrally and the general sacral shape is almost identical to Apatornis.
Contra Kurochkin, a ventral groove is absent in Zhyraornis, and pleurocoels
are present anteriorly in Ichthyornis and Guildavis. In 1996,
he elaborated his view, referring Zhyraornis to the Alexornithidae within
Enantiornithes, again based on comparison to Gobipteryx. He referred
it to Enantiornithes based on three characters. "General shortness"
cannot be evaluated due to the missing posterior ends, but the taper of the
sacrum and proportions of each vertebrae match Ichthyornis and Apatornis
closely. The most anterior portion is said to have small, equisized transverse
processes ventrally, but transverse processes two and three are much larger
than the others, as in Apatornis and somewhat less in Ichthyornis
(in the latter the third is largest, while the second is similar to the fourth).
The wide neural canal is shared with all birds and most small maniraptoriforms.
He referred it to Alexornithidae based on three characters. Dorsal curvature
is also present in Apatornis and many other birds. Contra Kurochkin,
the transverse processes are not equisized, being much larger in sacrals two
and three, as noted above. Finally, he states only two or three costal processes
are enlarged on the anterior synsacrum, but this is true in Apatornis,
and is not necessarily true in Gobipteryx, as the anterior one or two
sacrals are missing their lateral processes. Kurochkin later (2006) placed Zhyraornis
in Euornithes (his Ornithurae) based on unstated characters. In both his phylogram and cladogram,
it is placed between Confuciusornithidae (which Kurochkin viewed as basal euornithines
unrelated to dinosaurs, while enantiornithines were theropods) and Carinatae.
His cladogram specifies a placement more derived than Liaoningornis,
yet they share no known elements, so the result would be impossible in an actual
phylogenetic analysis. His phylogram indicates indicates he believed it branched
around Patagopteryx, Kuszholia and Gargantuavis. O'Connor
(2009) correctly criticized Kurochkin's (1995) characters and felt "a placement
in Ornithuromorpha may be more fitting", noting that both Zhyraornis
synsacra differed from enantiornithines. Yet she also declared the genus a nomen
dubium without demonstrating its published diagnostic characters are present
in any other taxon. Based on the diagnosis above, the taxon is valid.
Both species of Zhyraornis are similar in general morphology. The large
lateral fossae on centra one and two are likely continuations of such fossae
in the dorsal vertebrae, as seen in most Cretaceous avialans. Z. kashkarovi's sacrum
includes at least seven vertebrae, indicating they belong to Avialae
or perhaps Caenagnathoidea. Yet caenagnathoids with seven sacrals differ in
having all sacral vertebrae pleurocoelous, except Avimimus which has
apneumatic centra and a ventral median groove. Sapeornis' sacrum is dissimilar
in that the posterior transverse processes are most robust and the anterior
three are directed anteriorly. Confuciusornis differs in having broader
centra with a ventral groove and robust posterior transverse processes, though
the anterior centra are similar in having pleurocoels. Most enantiornithines
differ in having much broader centra with ventral grooves where known, and robust
posterior transverse processes. The Lecho Formation enantiornithine PVL-4041-4
is roughly similar, although the first centrum is narrower and the fifth and
sixth are broader. Also, the second and third transverse processes angle anteriorly
instead of posteriorly, while those of the fourth, sixth and seventh vertebrae
are more prominent. Gansus' is much broader after sacral two, with transverse
processes two and three directed perpendicular or anteriorly and those of five
and six more prominent. It seems to be similar in having fossae on sacral centra
one and two though. Hesperornithines and neornithines differ in having a heterocoelous
anterior articulation, while hesperornithines also differ in being non-pneumatic.
Ichthyornis' sacrum is extremely similar in centrum width, transverse
process size and direction, though the third transverse process is broader ventrally
and the fourth better developed. Importantly, they share a series of midsacral
reduced transverse processes, which is a carinate sensu lato character. It is also similar
in having pleurocoels on the first centrum, though seemingly not on the second.
A complication is YPM 1372, which fused an extra dorsal to its sacrum, giving
it two sacrals with pleurocoels. Yet the transverse process morphology in Zhyraornis
suggests its first sacral is homologous to the second sacral in YPM 1372 and
the first sacral in the Ichthyornis holotype. In Z. logunovi at
least, the second transverse process is as robust as the third, unlike Ichthyornis.
One major difference between Zhyraornis and Ichthyornis is that
the centra of the former narrow drastically after the third centrum. Apatornis'
is similar in being narrow and having a series of midsacrals with reduced transverse
processes. The transverse process size and orientation are similar where known.
Yet it differs from Zhyraornis in lacking a pleurocoel on sacral two
(sacral one is not preserved), and apparently having less narrow centra ventrally,
especially in the posterior centra (Nesov, 1984). Guildavis is similar
in having narrow anterior centra without a ventral groove, and a pleurocoel
on the first centrum. There may a be a pleurocoel in the second sacral as well,
but if so it is smaller than Zhyraornis. Poor preservation presents further
comparison. Which of these last three taxa Zhyraornis is more closely
related to is unknown, as the total number of vertebrae, number of vertebrae
with reduced transverse processes, and presence of parapophyses on the first
vertebra are unknown. It is here assigned to Carinatae sensu Chiappe incertae sedis.
References- Nesov, 1984a. Pterozavry i ptitsy pozdnego mela Sredney Azii. Paleontologicheskii Zhurnal. 1, 47-57.
Nesov, 1984b. Upper Cretaceous pterosaurs and birds from central Asia. Paleontological Journal. 1, 38-49.
Nessov, 1992. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Kurochkin, 1995. Synopsis of Mesozoic birds and early evolution of class Aves.
Archaeopteryx. 13, 47-66.
Kurochkin, 1996. A new enantiornithid of the Mongolian Late Cretaceous, and
a general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy
of Sciences, special issue. 50 pp.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia.
533-559.
Kurochkin, 2006. Parallel evolution of theropod dinosaurs and birds. Entomological
Review. 86(suppl. 1), S45-S58.
O'Connor, 2009. A systematic review of Enantiornithes (Aves: Ornithothoraces).
PhD thesis, University of Southern California. 586 pp.
Z. kashkarovi Nesov, 1984
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Holotype- (TsNIGRI 42/11915) (~225 mm) anterior synsacrum (27 mm)
Diagnosis (after Nesov, 1984) neural spine crest on synsacrum tall.
(after Nessov, 1992) sacrum more concave ventrally than Z. logunovi or
Apatornis; transverse processes in second and third sacrals with little
projection in dorsal view; transverse processes of second and third sacrals
extremely thin in ventral view.
(after Kurochkin, 2000) sacral centra four to eight <20% of dorsal width
of sacrum.
Other diagnoses- Kurochkin (2000) listed a couple additional characters
in his diagnosis. The slight anterior expansion of the first sacral centrum
is indistinguishable from Guildavis. He notes the largest transverse
processes (on sacrals two and three) are posteriorly angled (~55-60 degrees),
but Ichthyornis shows this can be quite variable (~55-71 degrees in YPM
1372 and perhaps 86 degrees in the holotype), so this cannot be used to diagnose
species. The sacrum does not appear more "extended" than in other
basal carinates.
Comments- Zhyraornis kashkarovi was first used in Nessov and Borkin
(1983) as a figure caption for the dorsal vertebra TsNIGRI 43/11915, which was
later made a paratype of the species. As no description accompanied the name,
it was a nomen nudum. It may belong to Zhyraornis, as it seems to be
an ornithothoracine but not an enantiornithine, hesperornithine or avian. It
is given its own entry here, however. Nesov made additional specimens paratypes
of Z. kashkarovi as well. The proximal scapula TsNIGRI 44/11915 is here
referred to Euornithes incertae sedis, while the humeral shaft TsNIGRI
45/11915 is referred to Maniraptora indet.. Isolated shafts of long bones (TsNIGRI
48/11915, 49/11915 and 50/11915) which were not described or illustrated are
similarly referred to Maniraptora indet..
The tall neural spine is the only one of Nesov's (1984) original diagnostic
characters for Z. kashkarovi that is still valid at the species level.
The others are dealt with under the genus entry. Nessov (1992) in his diagnosis
of the new species Z. logunovi noted numerous differences, a few of which
are apomorphic and are noted above.
References- Nessov and Borkin, 1983. New records of bird bones from the
Cretaceous of Mongolia and Soviet Middle Asia. USSR Academy of Sciences, Proceedings
of the Zoological Institute. 116, 108-110 (in Russian).
Nesov, 1984a. Pterozavry i ptitsy pozdnego mela Sredney Azii. Paleontologicheskii Zhurnal. 1, 47-57.
Nesov, 1984b. Upper Cretaceous pterosaurs and birds from central Asia. Paleontological Journal. 1, 38-49.
Nessov, 1992. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia.
533-559.
Z. logunovi Nessov, 1992
Mid-Late Turonian, Late Cretaceous
Bissekty Formation, Uzbekistan
Holotype- (ZIN PO 4600) (~200 mm) anterior synsacrum (~24 mm)
Diagnosis- (after Nessov, 1992b) wider anterior articular surface than
Z. kashkarovi; pleurocoel in first sacral vertebra larger than Z.
kashkarovi.
Other diagnoses- Of Nessov's (1992b) other listed diagnostic characters,
the narrow sacrum with prominent ventral ridge is also present in Z. kashkarovi.
The second sacral transverse process angles to be perpendicular to the sacrum
long axis distally, which is indeed unlike Z. kashkarovi (unless it is
broken in the latter), but is similar to Ichthyornis. The third sacral's
transverse processes angle posteriorly ~69-78 degrees, which is less than Z.
kashkarovi (~55-60 degrees), but Ichthyornis shows this can be quite
variable (~55-71 degrees in YPM 1372 and perhaps 86 degrees in the holotype),
so this cannot be used to diagnose species. The low amount of ventral concavity
seem to be primitive, as Apatornis is similar. The more ventrally placed
second vertebra's pleurocoel may be diagnostic, but the pneumatic features are
known to exhibit a high degree of variation between individuals and even between
sides of the vertebra. The well developed anterior transverse processes (in
dorsal view) and wide ventral struts supporting them are plesiomorphically similar
to Ichthyornis and Apatornis, though indeed dissimilar to Z.
kashkarovi. Nessov stated the upper ridge behind the contact of the second
and third sacrals was wider and better developed than in Z. kashkarovi,
but I don't see a difference. Most of the spinal nerve foramina are said to
be more anteroposteriorly compressed, but this is not apparent in the poor photocopy
available and has unknown variation.
Kurochkin (2000) listed two additional characters in his diagnosis. The abrupt
anterior expansion of the first sacral centrum is similar to Ichthyornis.
The sacrum is not "generally expanded and broadened" for a carinate,
only in comparison to the derived condition in Z. kashkarovi.
Comments- This specimen was discovered in 1989 and mentioned as a new
species of Zhyraornis (though unnamed) by Mourer-Chauvire (1989) and
Nessov (1992a). Kurochkin (1996) considered Z. logunovi to probably belong
to a separate genus than Z. kashkarovi based on the characters described
by Nessov, but they seem more similar to each other than to other Mesozoic birds,
with the narrow posterior centra and lateral fossae on sacral centrum two being
derived characters not present in Ichthyornis or Apatornis. In
contrast, O'Connor (2009) stated the holotypes "are not readily distinguishable;
the differences suggested by the diagnosis provided by Kurochkin (2003) [actually
2000] cannot be confirmed from published figures." I disagree and find
the characters cited in my diagnoses from Nessov's and Kurochkin's works to
be readily visible in their figures.
References- Mourer-Chauvire, 1989. Society of Avian Paleontology and
Evolution Information Newsletter. 3.
Nessov, 1992a. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478.
Nessov, 1992b. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Kurochkin, 1996. A new enantiornithid of the Mongolian Late Cretaceous, and
a general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy
of Sciences, special issue. 50 pp.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia.
533-559.
O'Connor, 2009. A systematic review of Enantiornithes (Aves: Ornithothoraces).
PhD thesis, University of Southern California. 586 pp.
unnamed ornithurine (Longrich, 2009)
Late Campanian, Late Cretaceous
Oldman Formation, Alberta, Canada
Material- (TMP 1988.087.0027; Ornithurine D; Devil's Coulee bird) proximal coracoid
Diagnosis- (after Longrich, 2009) robust coracoid neck; robust rim of
scapular cotyle; small, proximally placed nerve foramen with a slit-like ventral
opening; relatively small size.
Comments-
Longrich (2009) assigned this to his Ornithurae sensu Gauthier and de
Quieroz based on an anteriorly placed scapular facet. Agnolin (2010)
suggested it was a cimolopterygid, but Mohr et al.
(2021) correctly noted it lacks his proposed characters for the family-
distally extensive procoracoid process (presence of process "unclear"
according to Longrich); distally placed and enlarged
supracoracoid foramen; laterally angled glenoid.
References- Longrich, 2009. An ornithurine-dominated avifauna from the
Belly River Group (Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous
Research. 30(1), 161-177.
Agnolin, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina.
Studia Geologica Salmanticensia. 46(2), 99-119.
Mohr, Acorn, Funston and Currie, 2021 (2020 online). An ornithurine bird coracoid from the Late Cretaceous of Alberta, Canada. Canadian Journal of Earth Sciences. 58(2), 134-140.
unnamed ornithurine (Longrich, 2006)
Late Campanian, Late Cretaceous
Upper Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1998.068.0145) proximal carpometacarpus
Diagnosis- carpal fovea occupies entire proximal surface of metacarpal
I; scar possibly for pisiform ligament present on dorsal surface of metacarpal
II.
Comments- Longrich's phylogenetic analysis placed that taxon closer to
Aves than Apsaravis, but further than Ichthyornis and Limenavis. Despite this phylogenetic position and apparent diving adaptations (thick-walled bones;
distally placed extensor process), it is not especially similar to the only known hesperornithine carpometacarpal material (Pasquiaornis).
The latter differs in Longrich's characters 3 ("Distal carpals, ventral
ridge of carpal trochlea: radius of ventral ridge smaller than or
subequal to radius of dorsal ridge (0)"), 8 ("Metacarpal I, concave
proximal margin: absent (0)") and 15 ("Pisiform process, position on
metacarpal II: ... cranially displaced towards base of metacarpal I
(1)").
Reference- Longrich, 2006. An ornithurine bird from the Late Cretaceous
of Alberta, Canada. Canadian Journal of Earth Sciences. 43, 1-7.
unnamed ornithurine (Bell and Everhart, 2011)
Late Cenomanian, late Cretaceous
Lincoln Limestone Member of the Greenhorn Limestone Formation, Kansas, US
Material- (FHSM VP-17459) proximal coracoid
Comments- Discovered in Summer
2004, Bell and Everhart (2011) described this as Ichthyornithes indet.,
but the character they based this on ("prominent, medially projecting
acrocoracoid process") is also present in many avians such as
'cimolopterygids'.
Reference- Bell and Everhart, 2011. Remains of small ornithurine birds from a
Late Cretaceous (Cenomanian) microsite in Russell County, north-central
Kansas. Transactions of the Kansas Academy of Science. 114(1-2), 115-123.
Odontornithes Marsh, 1873
Definition- (Ichthyornis anceps, Hesperornis regalis <- Passer
domesticus) (Martyniuk, 2012)
= Odontognathae Wetmore, 1930
= Ichthyornithes sensu Clarke, 2004
Definition- (Ichthyornis dispar <- Struthio camelus, Tinamus
major, Vultur gryphus)
= Hesperornithes sensu Sereno, online 2005
Definition- (Hesperornis regalis <- Passer domesticus)
Comments- Marsh (1873) named the new subclass Odontornithes for Ichthyornis.
He later (1875a, b) included Hesperornis in Odontornithes as well, though
in a separate order. Wetmore (1930) named Odontognathae as a superorder containing
Hesperornithiformes and Ichthyornithiformes.
References- Marsh, 1873. On a new sub-class of fossil birds (Odontornithes).
American Journal of Science, 3rd series. 5, 161-162.
Marsh. 1875a. On the Odontornithes, or birds with teeth. American Journal of
Science, Series 3. 10(59), 403-408.
Marsh, 1875b. Odontornithes, or birds with teeth. The American Naturalist. 9(12),
625-631.
Wetmore, 1930. A systematic classification for the birds of the world. Proceedings
of the US National Museum. 76(24), 1-8.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Sereno, online 2005. Stem Archosauria - TaxonSearch. http://www.taxonsearch.org/dev/file_home.php
[version 1.0, 2005 November 7]
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Horezmavis Nessov and Borkin,
1983
H. eocretacea Nessov and Borkin, 1983
Early Cenomanian, Late Cretaceous
Khodzhakul Formation, Uzbekistan
Holotype- (ZIN PO 3390) (~285 mm) proximal tarsometatarsus
Comments- Horezmavis
was described as Aves (sensu lato) incertae sedis by Nessov and Borkin
(1983), though Nessov later (1992) assigned it to Gruiformes based on
resemblences to Ralli. Kurochkin (1995) considered it a gruiform based
on several characters, but Hope (2002) found these to have a broader
distribution within euornithines. The lateral position of the m.
tibialis cranialis tubercle is shared with most euornithines; the
intercotylar prominence is not as well developed as Aves; the presence
of two proximal vascular foramina is present in carinates sensu
Chiappe; a hypotarsus is present in Patagopteryx, Gansus and taxa as close to Aves as Changmaornis; and an elongate shaft is also found in such
taxa as Gansus, Hollanda, basal hesperornithines and Apsaravis.
Kurochkin (2000) later stated its position within Gruiformes was less
certain, but did feel it was a neognath. The characters he cites are also present
in more basal euornithines however. A completely fused tarsometatarsus is
present in all euornithines while a infracotylar fossa is present in songlingornithids
and more derived birds. Martin (1995) considered it an enantiornithine, but
this is surely incorrect based on the distal metatarsal fusion, proximal metatarsal
III which is displaced ventrally, intercotylar priminence, hypotarsus, presence
of two proximal vascular foramina, centrally placed m. cranialis tibialis tubercle,
and unreduced metatarsal IV. The character evidence thus suggests it is at least
as derived as Ichthyornis, but further resolution depends on more detailed
comparisons to basal Aves.
References- Nessov and Borkin, 1983. [New records of bird bones from
Cretaceous of Mongolia and Middle Asia] Trudy Zoologicheskogo Instituta Akademii
Nauk SSSR. 116, 108-110.
Nessov, 1992. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Kurochkin, 1995. Synopsis of Mesozoic birds and early evolution of class Aves.
Archaeopteryx. 13, 47-66.
Martin, 1995. The enantiornithines: terrestrial birds of the Cretaceous. Courier
Forschungsinstitut Senckenberg. 181, 23–36.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin, eds. The Age of Dinosaurs in Russia and Mongolia.
533-559.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
Ichthyornithes Marsh, 1873b
Official Definition- (Ichthyornis dispar <- Hesperornis regalis, Vultur gryphus) (Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022; Registration Number 555)
Other definition- (Ichthyornis dispar <- Struthio camelus, Tinamus
major, Vultur gryphus) (Clarke, 2004)
= Ichthyornithidae Marsh, 1873a (emended Furbringer, 1888)
= Ichthyornithides Gill, 1874
= Odontotormae Marsh, 1875b
= Pteropappi Stejneger, 1885
= Ichthyornithiformes Furbringer, 1888
Definition- (Ichthyornis anceps <- Hesperornis regalis, Gansus
yumenensis, Passer domesticus) (Martyniuk, 2012)
= Odontormae Steinmann and Doederlein, 1890
= Plegadornithidae Wetmore, 1962
= Angelinornithidae Kashin, 1972
Diagnosis- amphicoelous cervicals; acromion that does not
extend anteriorly past the coracoid condyle; internal index process
on manual phalanx II-1 (absent in Ichthyornis KUVP 2284- ontogenetic?).
Other diagnoses- Marsh (1873a, b) originally diagnosed Ichthyornidae,
Ichthyornithes and Odontornithes based on their amphicoelous vertebrae (only
the posterior dorsals were definitely amphicoelous in Apatornis, based
on its sacrum), which are plesiomorphic.
Marsh diagnosed Ichthyornithes (1875a) then Odontormae (1875b) by their plesiomorphic
presence of teeth placed in sockets (as in most archosaurs), a keeled sternum
(as in most ornithothoracines) and "developed wings" (as in most birds).
Comments- Marsh (1873a) named Ichthyornidae to include Ichthyornis
and Apatornis, which Furbringer (1888) emended to its proper form Ichthyornithidae.
Marsh later (1873b) placed ichthyornithids in the new order Ichthyornithes,
but in the 1875b publication, replaced Ichthyornithes with Odontotormae because
he thought the previous name was preoccupied. As Clarke (2004) noted though,
Marsh never mentioned which taxon supposedly preoccupied Ichthyornithes, and
recent searches for homonyms have been unsuccessful. Furbringer created Ichthyornithiformes
for a more inclusive group than Ichthyornithes (though with the same known contents),
which became the name generally used until Clarke phylogenetically defined Ichthyornithes
in her Ichthyornis monograph. Clarke (2002) incorrectly claimed Furbringer
never named the taxon and that it was only mistakenly attributed to him by Brodkorb.
Most recently Ichthyornithes was made official by Benito et al. (2022).
Wetmore (1962) named the Plegadornithidae for his new genus Plegadornis,
which he placed in the Ciconiiformes close to threskiornithids. Kashin (1972)
noted Plegadornis was preoccupied, so renamed it Angelinornis
and suggested the family be named Angelinornithidae. Angelinornis was
synonymized with Ichthyornis by Olson (1975), making Angelinornithidae a junior
synonym of Ichthyornithidae. It should be noted Plegadornithidae should only
be used for a family containing Plegadornis however.
Ex-ichthyornithines- Marsh (1873a) included Apatornis in Ichthyornithidae
and later Ichthyornithes and Odontotormae, which has been followed by most authors
(based largely on Iaceornis material after 1880) until Clarke (2004)
found a lack of supportive characters. Nesov (1984) assigned his new taxon
Zhyraornis to Ichthyornithiformes, which may be correct but has not been
supported with any valid characters yet. Nessov (1986) described a partial synsacrum
as Ichthyornis maltshevskyi, but this was placed in the new genus Lenesornis
by Kurochkin (1996) and seems to be a more basal ornithothoracine, perhaps an
enantiornithine. Martin (1987) assigned Ambiortus to the Ichthyornithiformes,
but this has not been supported by phylogenetic analyses. Nessov (1990) described
a dorsal vertebra as Ichthyornis minusculus,
but this seems to be an enantiornithine (Kurochkin, 1996). Several
specimens from the Bissekty Formation of Uzbekistan were assigned to
Ichthyornithiformes by Nessov (1992a, b), but are here placed as
Ornithothoraces incertae sedis (partial dentary ZIN PO 4608, and tooth
ZIN PO 4610) or Euornithes incertae sedis (proximal coracoid ZIN
PO 4605, and dorsal vertebra ZIN PO 4607). Bell and Everhart
(2011) described coracoid FHSM VP-17459 as Ichthyornithes indet., but
the character they based this on ("prominent, medially projecting
acrocoracoid process") is also present in many avians such as
'cimolopterygids'.
References- Marsh, 1873a. Notice of a new species of Ichthyornis.
American Journal of Science, 3rd series. 5, 74.
Marsh, 1873b. On a new sub-class of fossil birds (Odontornithes). American Journal
of Science, 3rd series. 5, 161-162.
Gill, 1874. in Baird, Brewer and Ridgway. North American Birds. Volume 1.
Marsh. 1875a. On the Odontornithes, or birds with teeth. American Journal of
Science, Series 3. 10(59), 403-408.
Marsh, 1875b. Odontornithes, or birds with teeth. The American Naturalist. 9(12),
625-631.
Stejneger, 1885. Birds. in Kingsley (ed). The Standard Natural History. Volume
4.
Furbringer, 1888. Untersuchungeb zur Morphologie und Systematik der Vogel. Amsterdam:
Holkema, 1751 pp.
Steinmann and Doederlein, 1890. Elemente der Palaontologie.
Wetmore, 1962. Notes on fossil and subfossil birds. Smithsonian Miscellaneous
Collections. 145, 1-17.
Kashin, 1972. New name for the genus Plegadornis. Ornitologiya. 10, 336-337.
Olson, 1975. Ichthyornis in the Cretaceous of Alabama. Wilson Bulletin.
87, 103-105.
Nesov, 1984a. Pterozavry i ptitsy pozdnego mela Sredney Azii. Paleontologicheskii Zhurnal. 1, 47-57.
Nesov, 1984b. Upper Cretaceous pterosaurs and birds from central Asia. Paleontological Journal. 1, 38-49.
Nessov, 1986. Pervaya nakhodka pozdnemelovoy ptitsyikhtiornisa v starom svete
i nekotoryye drugiye kosti ptits iz mela i paleogena Sredney Axii [The first
find of the Late Cretaceous bird, Ichthyornis, in the Old World, and
some other bird bones from the Cretaceous and Paleogene of Middle Asia]. in
Potapov (ed). Ekologicheskiye i faunisticheskiye issledovniya ptits. Trudy Zoologicheskogo
Instituta Akademii Nauk SSSR. 147, 31-38.
Martin, 1987. The beginning of the modern avian radiation. Documents des Laboratoires
de Geologie de la Faculte des Sciences de Lyon. 99, 9-20.
Nessov, 1990. Small Ichthyornis and other findings of the bird bones
from the Bissekty Formation (Upper Cretaceous) of Central Kizylkum Desert. Trudy
Zoologicheskogo Instituta Akademii Nauk SSSR. 21, 59-62.
Nessov, 1992a. Mesozoic and Paleogene birds of the USSR and their
paleoenvironments. In Campbell (ed.). Papers in Avian Paleontology
Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County
Science Series. 36, 465-478.
Nessov, 1992b. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Kurochkin, 1996. A new enantiornithid of the Mongolian Late Cretaceous, and
a general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy
of Sciences, special issue. 50 pp.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Bell and Everhart, 2011. Remains of small ornithurine birds from a
Late Cretaceous (Cenomanian) microsite in Russell County, north-central
Kansas. Transactions of the Kansas Academy of Science. 114(1-2), 115-123.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Benito, Chen, Wilson, Bhullar, Burnham and Field, 2022. Forty new specimens of Ichthyornis provide unprecedented insight into the postcranial morphology of crownward stem group birds. PeerJ. 10:e13919.
Ichthyornis Marsh, 1872b
Definition- (the clade stemming from an ancestor that possessed amphicoelous
cervical centra, an acromion that does not extend anteriorly past the coracoid
condyle, a dorsal ulnar condyle where the posterior extent of the articular
surface is equal to the width of the articular surface across its distal end,
an oval scar on the posteroventral surface of the distal radius in the center
of the ligamentous depression, and a large tubercle developed on the laterodistal
surface of metacarpal II, homologous with those in Ichthyornis dispar;
Ichthyornis dispar <- Struthio camelus, Tinamus major, Vultur gryphus)
(Clarke, 2004)
= Colonosaurus Marsh, 1872c
= Plegadornis Wetmore, 1962 (preoccupied Brehm, 1855)
= Angelinornis Kashin, 1972
Not Ichthyornis- A number of other species have been referred to Ichthyornis
in the past. Marsh (1873a) described Ichthyornis celer, but later referred
it to its own genus Apatornis in 1873b. Marsh (1880) referred Graculavus
lentus to Ichthyornis to form the new taxon Ichthyornis lentus,
but this was placed in the new galliform genus Austinornis by Clarke
(2002, 2004). Ichthyornis tener was named by Marsh (1880) and assigned
to the new genus Guildavis by Clarke. Martin and Stewart (1982) described
a dorsal vertebra from the Vermillion River Formation of Manitoba as Ichthyornis
sp., but Clarke identified it as an enantiornithine. Zinsmeister (1985) reported tentative Ichthyornis
material from the Lopez de Bertodano Formation of Antarctica, but
Chatterjee (pers. comm. 12-6-2020) stated "It was misidentified in the
field. These were some shark teeth." They are assigned to
Odontaspidae here (Mortimer, online 2020). Nessov (1986)
described a partial synsacrum as Ichthyornis maltshevskyi, but this was placed
in the new genus Lenesornis by Kurochkin (1996) and seems to be a more
basal ornithothoracine, perhaps an enantiornithine. Nessov (1990) described
a dorsal vertebra as Ichthyornis minusculus, but this seems to be an
enantiornithine (Kurochkin, 1996).
References- Brehm, 1855. Der vollst�ndige Vogelfang. Weimar. 416 pp.
Marsh, 1872b. Notice of a new and remarkable fossil bird. American Journal of
Science, 3rd series. 4, 344.
Marsh, 1872c. Notice of a new reptile from the Cretaceous. American Journal
of Science, 3rd series. 4(23), 406.
Marsh, 1873a. Notice of a new species of Ichthyornis. American Journal
of Science, 3rd series. 5, 74.
Marsh, 1873b. On a new sub-class of fossil birds (Odontornithes). American Journal
of Science, 3rd series. 5, 161-162.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Wetmore, 1962. Notes on fossil and subfossil birds. Smithsonian Miscellaneous
Collections. 145, 1-17.
Kashin, 1972. New name for the genus Plegadornis. Ornitologiya. 10, 336-337.
Olson, 1975. Ichthyornis in the Cretaceous of Alabama. Wilson Bulletin.
87, 103-105.
Martin and Stewart, 1982. An ichthyornithiform bird from the Campanian of Canada.
Canadian Journal of Earth Sciences. 19, 324-327.
Zinsmeister, 1985. 1985 Seymour Island expedition. Antarctic
Journal of U.S. 20, 41-42.
Nessov, 1986. Pervaya nakhodka pozdnemelovoy ptitsyikhtiornisa v starom svete
i nekotoryye drugiye kosti ptits iz mela i paleogena Sredney Axii [The first
find of the Late Cretaceous bird, Ichthyornis, in the Old World, and
some other bird bones from the Cretaceous and Paleogene of Middle Asia]. in
Potapov (ed). Ekologicheskiye i faunisticheskiye issledovniya ptits. Trudy Zoologicheskogo
Instituta Akademii Nauk SSSR. 147, 31-38.
Nessov, 1990. Small Ichthyornis and other findings of the bird bones
from the Bissekty Formation (Upper Cretaceous) of Central Kizylkum Desert. Trudy
Zoologicheskogo Instituta Akademii Nauk SSSR. 21, 59-62.
Kurochkin, 1996. A new enantiornithid of the Mongolian Late Cretaceous, and
a general appraisal of the Infraclass Enantiornithes (Aves). Russian Academy
of Sciences, special issue. 50 pp.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Mortimer, 2020 online. https://theropoddatabase.blogspot.com/2020/12/antarctic-ichthyornis-solved.html
I. dispar Marsh, 1872b
Definition- (the species that includes YPM 1450) (Clarke, 2004)
?= Graculavus anceps Marsh, 1872a
= Colonosaurus mudgei Marsh, 1872c
?= Graculavus agilis Marsh, 1873b
= Ichthyornis victor Marsh, 1876
?= Ichthyornis agilis (Marsh, 1873) Marsh, 1880
?= Ichthyornis anceps (Marsh, 1872a) Marsh, 1880
?= Ichthyornis validus Marsh, 1880
= Plegadornis antecessor Wetmore, 1962
= Angelinornis antecessor (Wetmore, 1962) Kashin, 1972
= Ichthyornis antecessor (Wetmore, 1962) Olson, 1975
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Holotype-
(YPM 1450; holotype of Colonosaurus
mudgei) (~240 mm; adult) maxillary fragment, nasal fragment, lacrimal fragment, braincase,
mandibles (87 mm), posterior cervical vertebra (5.5 mm), posterior cervical
vertebra (6 mm), mid dorsal vertebra (5.8 mm), posterior dorsal vertebra (6
mm), several proximal dorsal ribs, synsacrum (26.2 mm), ossified tendons, distal
coracoid, anterior sternum, incomplete humeri (58.4 mm), distal radius, ulnae
(61.5 mm), distal carpometacarpus, femur (24.7 mm), distal femur, incomplete
tibiotarsus (44.5 mm), fragments
Referred- (AMNH 30586) skeleton (AMNH online)
(BHI 6421) partial quadratojugal, quadrate, posterior mandibles, postcrania including manual phalanx II-1 (Field et al., 2018)
(FHSM VP-329) proximal scapula, incomplete coracoid, humerus (FHSM online)
(FHSM VP-2058) distal humerus (FHSM online)
(FHSM VP-2179) distal tarsometatarsus (FHSM online)
(FHSM VP-2180) incomplete radius, ulna (FHSM online)
(FHSM VP-2503; = SMM 2503; "SMM 13520" of Martin and Stewart, 1977)
partial dentary, splenial, five cervical vertebrae, scapula, coracoids, partial
furcula, sternum, humeri, radius, proximal ulnae, pisiform, carpometacarpus, phalanx
II-1, phalanx II-2, femoral shaft, incomplete tibiotarsus (Martin and Stewart,
1977)
(FHSM VP-15573) distal humerus, limb fragment (FHSM online)
(FHSM VP-15574) proximal coracoid (FHSM online)
(FHSM VP-17317) incomplete coracoid (FHSM online)
(FHSM VP-18702) skull, mandibles (one anterior), partial skeleton
including metacarpal II and manual phalanx II-1 (Field et al., 2018)
(KUVP 2294) humeral fragment (Chinsamy et al., 1998)
(KUVP 119673) jugal, quadrate, incomplete mandible, incomplete postcranial skeleton including coracoids and humerus
(Burnham and Hines, 2005)
(NHMUK A905) partial postcranium including scapula, sternum and humerus (Harrison
and Walker, 1973)
(RMDRC coll.) specimen including premaxillae, maxilla and postcrania (Maltese, 2017 online)
?(YPM 1208; holotype of Graculavus anceps) (~233 mm;
adult) distal carpometacarpus (Marsh, 1872a)
(YPM 1209; holotype of Graculavus agilis) (size of YPM 1724; adult) proximal
carpometacarpus (Marsh, 1873b)
?(YPM 1446) (adult) incomplete coracoid (Marsh, 1880)
(YPM 1447) (~292 mm; adult) humerus (71.1 mm) (Marsh, 1880)
(YPM 1452; holotype of Ichthyornis victor) (adult) proximal scapula,
proximal coracoid, three humeral fragments (12.5 mm wide distally), ulna (lost)
(Marsh, 1876)
(YPM 1453) (~288 mm; adult) ulna (73.8 mm) (Marsh, 1880)
(YPM 1454) (adult) ulna (Clarke, 2004)
(YPM 1456) (adult) distal tarsometatarsus (Marsh, 1880)
(YPM 1457) (adult) humerus (11 mm wide distally), radius, ulna (Marsh, 1880)
(YPM 1458) (adult) scapula, coracoid (Marsh, 1880)
(YPM 1459) (adult) premaxillary fragment (Marsh,
1880)
(YPM 1460) (adult) tooth, ulna (Clarke and Chiappe, 2001)
(YPM 1461) (adult) dorsal ribs, coracoid, partial sternum, humerus (Marsh, 1880)
(YPM 1462) (adult) ulna (Clarke and Chiappe, 2001)
(YPM 1463) (adult) manual phalanx II-1 (21 mm) (Marsh, 1880)
(YPM 1464) (adult) distal tarsometatarsus (Marsh, 1880)
(YPM 1718) (adult) scapula, coracoid (Marsh, 1880)
(YPM 1719) (adult) coracoid (Clarke, 2004)
(YPM 1720) (adult) humerus (Clarke, 2004)
(YPM 1721) (adult) humerus (Clarke, 2004)
(YPM 1722) (adult) humerus (Clarke, 2004)
(YPM 1723) (adult) tibiotarsus (57 mm) (Marsh, 1880)
(YPM 1724) (adult) carpometacarpus (39.5 mm) (Marsh, 1880)
(YPM 1725) (adult) humerus (Clarke, 2004)
(YPM 1726) (adult) manual phalanx II-1 (20.8 mm) (Marsh, 1880)
(YPM 1727) (adult) scapula, coracoid (Marsh, 1880)
(YPM 1728) (adult) posterior nasals, frontals, braincase (Clarke, 2004)
(YPM 1729) (adult) humerus (Clarke, 2004)
(YPM 1730) (~252 mm; adult) humerus (62.5 mm), carpometacarpus (31.5 mm) (Marsh,
1880)
(YPM 1731) (adult) ulna (Chiappe, 2002)
(YPM 1732) (adult) partial posterior dorsal vertebra, posterior dorsal vertebra,
posterior dorsal vertebra, synsacrum, ossified tendons, first caudal vertebra
(3.1 mm), second caudal vertebra (3.2 mm), third caudal vertebra (3.6 mm), fourth
caudal vertebra (3.2 mm), fifth caudal vertebra (3.4 mm), anterior pygostyle,
incomplete ilium, proximal pubis (26 mm), incomplete ischium, proximal femur,
partial tibiotarsi (57 mm), pedal phalanx II-2 (9 mm) (Marsh, 1880)
(YPM 1733) (adult) atlas (2.7 mm), axis (7 mm), third cervical vertebra (6 mm),
posterior cervical vertebra (6 mm), anterior dorsal vertebra (5.5 mm), anterior
dorsal centrum, mid dorsal vertebra (6.7 mm), partial posterior dorsal vertebra,
partial posterior dorsal centrum, posterior dorsal centrum, synsacrum, ossified
tendons, scapula, incomplete coracoid, distal humerus, radius, partial ilium?
(Marsh, 1880)
(YPM 1735) (adult) mandible (Marsh, 1880)
(YPM 1736) (adult) carpometacarpus (Chiappe, 2002)
(YPM 1737) (adult) humerus (Clarke, 2004)
(YPM 1738) (190-206 mm; adult) distal humerus (7.5 mm wide distally) (Marsh,
1880)
(YPM 1739) (adult) tarsometatarsus (58 mm) (Marsh, 1880)
?(YPM 1740; holotype of Ichthyornis validus) (~267 mm; subadult) ulna
(68.5 mm) (Marsh, 1880)
(YPM 1741) (adult) scapula, coracoid, humerus, radius (71 mm) (Marsh, 1880)
(YPM 1742) (~294 mm; adult) humerus (71.5 mm) (Marsh, 1880)
(YPM 1743) (adult) coracoid (34 mm) (Marsh, 1880)
(YPM 1744) (adult) ulna (Clarke, 2004)
(YPM 1745) (adult) coracoid (32 mm) (Marsh, 1880)
(YPM 1746) (adult) coracoid (Clarke, 2004)
(YPM 1747) (adult) humerus (Clarke, 2004)
(YPM 1748) (adult) humerus (Clarke, 2004)
(YPM 1749) (adult) anterior mandible, partial humerus (Marsh, 1880)
(YPM 1750) (adult) humerus (Clarke, 2004)
(YPM 1751) (adult) carpometacarpus (Clarke, 2004)
(YPM 1752) (adult) carpometacarpus (Chiappe, 2002)
(YPM 1753) (adult) scapula (Chiappe, 2002)
(YPM 1754) (adult) distal tibiotarsus (Clarke, 2004)
(YPM 1755) (adult) furcular fragment, humerus (70.6 mm), radius, ulna, carpometacarpus
(36.6 mm), manual phalanx II-1 (21.2 mm) (Marsh, 1880)
(YPM 1756) (~252 mm; adult) humerus (61.4 mm)
(YPM 1757) (adult) coracoid, humerus, ulna (Clarke, 2004)
(YPM 1758) (adult) radius, ulna (Chiappe, 2002)
(YPM 1759) (adult) manual phalanx I-1, phalanx II-1 (Marsh, 1880)
(YPM 1761) (>240 mm; adult) mandibular fragment (Elzanowski et al., 2001)
(YPM 1762) (adult) humerus (Clarke, 2004)
(YPM 1763) (adult) scapula, coracoid, humerus, radial fragment (Clarke, 2004)
(YPM 1764) (~269 mm; adult) partial humerus (10.5 mm wide distally), ulna (Olson,
1975)
(YPM 1765) (adult) coracoid (Chiappe, 2002)
(YPM 1766) (~240 mm; adult) coracoid (Marsh, 1880)
(YPM 1767) (adult) coracoid (Chiappe, 2002)
(YPM 1768) (adult) coracoid (Chiappe, 2002)
(YPM 1769) (adult) carpometacarpus (Clarke, 2004)
(YPM 1770) (adult) radius (Chiappe, 2002)
(YPM 1771) (adult) tarsometatarsus (Chiappe, 2002)
(YPM 1772) (adult) scapula (Chiappe, 2002)
(YPM 1773) (adult) endocast?, scapula, coracoid, humerus, radius, carpometacarpus
(39.4 mm) (Chiappe, 2002)
(YPM 1774) (adult) coracoid (Clarke, 2004)
(YPM 1775) (adult) quadrates (one partial), anterior mandible, axis, anterior dorsal vertebra, partial
pygostyle(?), humerus, radius, ulna, carpometacarpus, phalanx II-1, incomplete
phalanges III-1, distal femur, distal tibiotarsus (Marsh, 1880)
(YPM 1776) (adult) coracoid (Chiappe, 2002)
(YPM 6264) (<240 mm; adult) posterior mandible (Gingerich, 1972)
(YPM 9685) (~300-317 mm; adult) humerus (Clarke, 2004)
(YPM 56577) (adult) scapula, coracoid (Clarke, 2004)
Early Turonian, Late Cretaceous
Kaskapau Formation, Alberta, Canada
(UA 18456) (~220 mm) humerus (53.5 mm) (Fox, 1984)
Campanian, Late Cretaceous
Pembina Member of the Vermillion River Formation, Manitoba, Canada
(CFDC B.80.05.14) femur (CFDC online)
Campanian, Late Cretaceous
Chico Formation, California, US
(UCMP 170785) partial humerus (Hilton et al., 1999)
Turonian, Cretaceous
Juan Lopez Member of Mancos Shale, New Mexico, US
(YPM 9148) (~238 mm) incomplete humerus (58 mm) (Lucas and Sullivan, 1982)
Early Coniacian, Late Cretaceous
Ector Chalk Formation of the Austin Group, Texas, US
(TMM 31051-24) (~262 mm) humerus (63.8 mm) (Parris and Echols, 1992)
(TMM 31051-25) (~257 mm) humerus (62.5 mm), partial ulna, partial radius, partial
carpometacarpus (Parris and Echols, 1992)
Coniacian, Late Cretaceous
Gober Formation, Texas, US
(ET 4396) proximal carpometacarpus (Parris and Echols, 1992)
Campanian, Late Cretaceous
Pflugerville Formation, Texas, US
(TMM 42522-1) (~254 mm) distal humerus (10.1 mm wide distally) (Parris and Echols,
1992)
Late Coniacian-Early Campanian, Late Cretaceous
Upper Austin Group, Mexico
(MUZ-689) humerus (56 mm) (Porras-Muzquiz et al., 2014)
Early Campanian, Cretaceous
Mooreville Chalk, Alabama, US
(ALMNH 3316; = Red Mountain Museum coll.) premaxillae, partial
maxillae, anterior mandible, vertebrae, pelvis, limb elements including
manual phalanx II-1 (Lamb, 1997; described by Field et al., 2018)
(D2K coll.) material (Clarke, 2004)
(UAM PV93.2.133-1) tooth fragment (Dumont et al., 2016)
(UAM PV93.2.133-2) tooth fragment (Dumont et al., 2016)
(USNM 22820; holotype of Plegadornis antecessor) (~269 mm) distal humerus
(10.5 mm wide distally) (Wetmore, 1962)
Late Cretaceous?
US?
(USNM 11641) radius (Chiappe, 1996)
Diagnosis- (after Clarke, 2004) anteromedial pneumatic foramen in quadrate; proximal caudal
prezygopophyses clasp dorsal surface of preceding vertebra; pit-shaped fossa at distal
tip of bicipital crest (also in Tianyuornis) dorsal ulnar condyle where the
posterior extent of the articular surface is equal to the width of the articular
surface across its distal end (unknown in other non-avian euornithines except
Apsaravis); oval scar on the posteroventral surface of the distal radius
in the center of the ligamentous depression; large tubercle developed on the
laterodistal surface of metacarpal II.
Other diagnoses- Marsh (1872a) originally diagnosed Graculavus anceps
as being larger than G. velox (which was not otherwise comparable, being
based on a humerus; contra Clarke, 2004), and differing from the phalacrocoracid
"Graculus violaceus" (now Phalacrocorax pelagicus) in
several characters. These were- broader and flat articular surface for phalanx
II-1; smaller and oval articular surface for phalanx III-1; larger distal tubercle
between these surfaces. Obviously comparisons to cormorants are of little use,
as Ichthyornis is not even a crown clade bird.
Marsh (1872b) suggested amphicoelous cervicals were diagnostic, but this is also present in NHMM/RD 271.
Marsh (1872c) distinguished Colonosaurus mudgei from mosasaurs in its
lack of a conspicuous Meckelian groove, but this is common in derived birds.
Marsh (1873b) distinguished Graculavus agilis from G. anceps based
on its smaller size, gracility and reduced carpal fossa. As Clarke (2004) noted,
the first two differences do not seem to exist, while the third is unknown in
the anceps holotype, since that only preserves the distal carpometacarpus.
Marsh (1876) distinguished Ichthyornis victor from I. dispar based
on its larger size, but Clarke (2004) determined that there was a continuous
variation in size of Ichthyornis specimens from the Smoky Hills Chalk
and that no morphological differences between small and large specimens were
apparent besides a few forelimb scars being more prominent on larger ones.
Marsh (1880) distinguished I. anceps from I. dispar based on a
more slender mandible with more teeth, based on a referred specimen (YPM 1749)
that cannot be compared to the anceps holotype. While Clarke (2004) thought
it might be "slightly more delicate" than YPM 1450, she noted it contained
the same number of teeth. Marsh distinguished I. victor from I. dispar
based on the stouter and deeper mandible of YPM 1735, though Clarke notes its
proportions cannot be determined as it is incomplete.
Harrison (1973) listed two humeral characters as diagnostic of Ichthyornis-
dorsally projecting deltopectoral crest and small bicipital crest, but Clarke
(2004) found these both to be plesiomorphic for birds.
Olson (1975) distinguished I. antecessor from supposed I. dispar
specimen YPM 1764 based on several characters- more gracile humeral shaft; shallower
and more distally positioned brachial fossa; ectepicondylar process more prominent;
pit at base of ectepicondylar process shallower. Clarke (2004) noted the I.
dispar holotype is slender as in the I. antecessor holotype and that
the other differences were minor and vary in Smoky Hill Ichthyornis specimens.
Clarke (2004) suggested several diagnostic characters, at least two of which are now known in NHMM/RD 271- acromion that does
not extend anteriorly past the coracoid condyle; internal index process on manual phalanx
II-1.
Comments- While multiple species of Smoky Hill Chalk Ichthyornis
were recognized early on, the lack of proper diagnoses made referral of remains
to the species level uncertain through the 1900's. Elzanowski (1995), Clarke
(1999, 2000), Clarke and Chiappe (2001) and Chiappe (2002) all noted the taxonomic
mess and only provisionally referred elements not preserved in the holotype
(or specimens which shared elements with the holotype) to the taxon, fearing
multiple species were represented. Clarke (2002) examined all the specimens
at the YPM for her thesis, removing some from Ichthyornis and synonymizing
the others into one species, which she called Ichthyornis dispar. This
study was published in 2004 in a slightly modified version that mostly differed
in lacking several taxa in its phylogenetic analysis. Her taxonomy has been
followed in the recent literature.
The holotype of Ichthyornis anceps (the distal carpometacarpus YPM 1208)
was discovered in 1870 and described by Marsh (1872a) as Graculavus anceps.
Marsh assigned it to Graculavus because he thought it resembled phalacrocoraciids,
which he placed Graculavus velox near as well. Marsh (1880) later placed
anceps in Ichthyornis without comment, also referring the mandible
and partial humerus YPM 1749 to the species (though they are not comparable
to the type). Shufeldt (1915) believed anceps was too fragmentary and
distorted to diagnose or place precisely within Aves. However, Clarke (2004)
noted it has Ichthyornis' apomorphic distal metacarpal tubercle and does
not differ from the I. dispar holotype except in size. Clarke misinterpreted
the ICZN in respect to Ichthyornis anceps vs. I. dispar when she
sank the former into the latter though. Although I. anceps cannot be
the type species of Ichthyornis, it can be a senior synonym of of I.
dispar. Furthermore, according to the 1999 edition of the ICZN, I. anceps
is not a nomen oblitum, as it was used as a valid species by Stewart
(1990). While previously this website used I. anceps as a senior synonym of I. dispar,
the recent recognition of Belgian NHMM/RD 271 as a distinct species of
ichthyornithine complicates matters as it does not preserve a
carpometacarpus. Thus anceps cannot be distinguished from it and should not be the holotype of Smoky Hill ichthyornithines. Similar issues arise for agilis and validus,
as NHMM/RD 271 also lacks a preserved ulna, but further consideration
is delayed pending redescription and naming of the Belgian taxon.
Marsh (1872b) briefly described Ichthyornis dispar as a partial bird
postcranium and a week later (1872c) described Colonosaurus mudgei as
reptilian mandibles similar to mosasaurs. However, these are based on the remains
of one individual, as Marsh later (1873a) realized. Marsh described Ichthyornis
dispar in more detail in 1873a, 1875a, 1875b and especially 1880. In the
latter publication, Marsh also referred YPM 1718, 1723 and 1730 to I. dispar
preseumbly based on size. Gregory (1952) believed the mandibular elements (including
Colonosaurus) belonged to juvenile individuals of the mosasaur Clidastes,
which was followed by several later authors. Gingerich (1972) described a posterior
mandible as Ichthyornis cf. dispar, and agreed with Marsh, Russell (1967)
and Walker (1967) that the toothed mandibles did belong to Ichthyornis.
Olson (1975) referred YPM 1764 provisionally to I. dispar, pending a
revision of Ichthyornis by Brodkorb which never appeared. Paris and Echols
(1992) described a humerus and partial forelimb from the Ector Chalk Formation
of Texas as I. dispar, though they are currently catalogued as I.
victor in the TMM collections.
Marsh (1873b) named Graculavus agilis based on a proximal carpometacarpus
(YPM 1209) found in 1872. The description was extremely brief and no type material
was mentioned, though Marsh referred both Graculalvus anceps and G.
agilis to the Natatores. Marsh (1880) later placed agilis in Ichthyornis
without comment and referred the ulna YPM 1453 to the species (though it is
not comparable to the type). Shufeldt (1915) believed the holotype was indeterminate
and impossible to place precisely within Aves. Clarke (2004) found agilis
was identical to other Smoky Hill Ichthyornis specimens, so synonymized
it with I. dispar.
Ichthyornis victor was discovered in 1876 and described that year by
Marsh as a new larger species of Ichthyornis. This was based on YPM 1452,
which consists of three partial forelimb elements. Marsh (1880) described and
referred numerous specimens to I. victor- YPM 1447, 1456, 1457, 1458,
1461, 1463, 1464, 1724, 1726, 1727, 1732, 1733, 1735, 1739, 1741, 1742, 1743,
1745 and 1775. While a partial coracoid was originally associated with YPM 1459,
Clarke (2004) noted it articulates perfectly with a partial coracoid from YPM
1458, so was moved to that specimen. Hope (2002) illustrates these specimens
as Ichthyornis sp., with the old coracoid number. Chinsamy et al. (1998)
described the histology of KUVP 2294, a specimen they referred to I. victor.
Clarke (1999) considered I. victor a chimera, because the mounted skeleton
which was incorrectly labeled as the holotype actually contained elements from
several Ichthyornis specimens (YPM 1447, 1453, 1461, 1724, 1728, 1732,
1733, 1739, 1741) as well as what would become the holotype of Iaceornis
(which was previously noticed by Howard, 1955 and Elzanowski, 1995). Clarke
(2004) noted YPM 1732 differs from the I. dispar holotype in having twelve
sacral vertebrae, though the victor holotype is identical to dispar
except in size. If the species really are distinct and diagnosed partially by
size, I. anceps would be the valid name for the large species (with agilis,
victor and validus as synonyms) while I. dispar would be
the valid name for the small species.
Ichthyornis validus based on an ulna (YPM 1740) discovered in 1877 and
not diagnosed by Marsh when he named it in 1880. Brodkorb (1967) claimed a radius
was also known for YPM 1740, but this seems to be untrue. The partial coracoid
YPM 1446 was referred to validus by Marsh (1880) without comment. Clarke
(2004) noted it was more robust and larger than most other YPM specimens, the
supracoracoid foramen did not lie in a groove, and that there is a unique groove
extending from the supracoracoid foramen in the triossial canal. The holotype
is the only subadult YPM specimen of Ichthyornis known, and is larger
than some adult specimens such as the dispar holotype. Clarke synonymized
it with I. dispar since it is morphologically identical.
Wetmore (1962) described a distal humerus (USNM 22820) as Plegadornis antecessor,
which he thought was a ciconiiform close to threskiornithids. Kashin (1972)
noted that Plegadornis was preoccupied by a genus named by Brehm in 1855,
which in turn is a junior synonym of the threskiornithid genus Plegadis.
Thus he renamed the genus Angelinornis. Olson (1975) synonymized Angelinornis
with Ichthyornis but retained Ichthyornis antecessor as a valid
species. Paris and Echols (1992) described a distal humerus (TMM 42522-1) from
the Pflugerville Formation of Texas and proximal carpometacarpus (ET 4396) from
the Gober Formation of Texas and referred them to Ichthyornis antecessor.
The humerus was referred because it was thought to live at a later time than
Smoky Hill Ichthyornis and compare better morphologically to the antecessor
holotype, but the former is not necessarily true while Clarke notes it is equally
similar to the I. dispar holotype. It is currently catalogued as I.
sp. in the TMM collections. The carpometacarpus was only tentatively referred
based on stratigraphy and supposed differences from Smoky Hill Ichthyornis
material, but Clarke could not confirm these differences. As noted above, Clarke
determined the supposedly distinct characters of antecessor fell within
the range of individual variation for Smoky Hill Chalk Ichthyornis, so
synonymized this species with I. dispar.
Martin and Stewart (1977) described the jaws of a skeleton found in 1970, which
was found in 1970 and referred to Ichthyornis sp.. While they referred
to this specimen as SMM 13520, though it is actually 2503. Clarke (2004) referred
this specimen to I. dispar.
Lucas and Sullivan (1982) described a humerus (YPM 9148) from the Mancos Shale
in New Mexico found in 1979 as Ichthyornis sp., but Clarke (2004) referred
it to I. dispar.
KUVP 119673 was found in 1992 and was announced by Burnham and Hines
(2005), but its fragmentary skull was described in detail by Fields et
al. (2018). FHSM VP-18702 was found on August 17 2014 and its
nearly complete skull was described by Field et al.. The latter
study also redescribed and refigured all known Ichthyornis cranial elements, but the postcrania of the new specimens remain undescribed.
References- Marsh, 1872a. Preliminary description of Hesperornis regalis,
with notices of four other new species of Cretaceous birds. American Journal
of Science, 3rd series. 3, 359-365.
Marsh, 1872b. Notice of a new and remarkable fossil bird. American Journal of
Science, 3rd series. 4, 344.
Marsh, 1872c. Notice of a new reptile from the Cretaceous. American Journal
of Science, 3rd series. 4(23), 406.
Marsh, 1873a. On a new sub-class of fossil birds (Odontornithes). American Journal
of Science, 3rd series. 5, 161-162.
Marsh, 1873b. Fossil birds from the Cretaceous of North America. American Journal
of Science, 3rd series. 5, 229-230.
Marsh. 1875a. On the Odontornithes, or birds with teeth. American Journal of
Science, Series 3. 10(59), 403-408.
Marsh, 1875b. Odontornithes, or birds with teeth. The American Naturalist. 9(12),
625-631.
Marsh, 1876. Notice of new Odontornithes. American Journal of Science, 3rd series.
11, 509-511.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Marsh, 1883. Birds with teeth. 3rd Annual Report of the Secretary of the Interior.
3, 43-88.
Shufeldt, 1893. Comparative osteological notes on the extinct bird Ichthyornis.
Journal of Anatomy and Physiology. 27(3), 336-342.
Williston, 1898. Birds. The University Geological Survey of Kansas, Part 2.
4, 43-53.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions
of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Edinger, 1951. The brains of the Odontognathae. Evolution. 5(1), 6-24.
Gregory, 1952. The jaws of the Cretaceous toothed birds Ichthyornis and
Hesperornis. Condor. 54(2), 73-88.
Howard, 1955. A new wading bird from the Eocene of Patagonia. American Museum
Novitates. 1710, 25 pp.
Wetmore, 1962. Notes on fossil and subfossil birds. Smithsonian Miscellaneous
Collections. 145, 1-17.
Brodkorb, 1967. Catalogue of fossil birds: part 3 (Ralliformes, Ichthyornithiformes,
Charadriiformes). Bulletin of the Florida State Museum (Biological Sciences).
11, 99-220.
Russell, 1967. Systematics and morphology of American mosasaurs. Peabody Museum
of Natural History, Yale University Bulletin. 23, 1-240.
Walker, 1967. Revival of interest in the toothed birds of Kansas. Kansas Academy
of Science, Transactions. 70(1), 60-66.
Gingerich, 1972. A new partial mandible of Ichthyornis. Condor. 74, 471-473.
Kashin, 1972. New name for the genus Plegadornis. Ornitologiya. 10, 336-337.
Harrison, 1973. The humerus of Ichthyornis as a taxonomically isolated
character. Bulletin of the British Ornithological Club. 93, 123-126.
Harrison and Walker, 1973. Wyleyia: A new bird humerus from the Lower
Cretaceous of England. Palaeontology. 16(4), 721-728.
Olson, 1975. Ichthyornis in the Cretaceous of Alabama. Wilson Bulletin.
87, 103-105.
Martin and Stewart, 1977. Teeth in Ichthyornis (Class: Aves). Nature.
195, 1331-1332.
Lucas and Sullivan, 1982. Ichthyornis in the Late Cretaceous Mancos shale
(Juan Lopez member), northwestern New Mexico. Journal of Paleontology. 56, 545-547.
Fox, 1984. Ichthyornis (Aves) from the early Turonian (Late Cretaceous)
of Alberta. Canadian Journal of Earth Sciences. 21, 258-260.
Stewart, 1988. A new specimen of Ichthyornis, and its implications for
interpreting relationships of the group. Second International Symposium of the
Society of Avian Paleontology and Evolution.
Stewart, 1990. Niobrara Formation vertebrate stratigraphy. In Bennett (ed).
Niobrara Chalk excursion guidebook. Lawrence: University of Kansas Museum of
Natural History. 19-30.
Parris and Echols, 1992. The fossil bird Ichthyornis in the Cretaceous
of Texas. Texas Journal of Science. 44, 201-212.
Elzanowski, 1995. Cretaceous birds and avian phylogeny. Courier Forschungsinstitut
Senckenberg. 181, 37-53.
Chiappe, 1996. Late Cretaceous birds of Southern South America: Anatomy and
systematics of Enantiornithes and Patagopteryx deferrariisi. In Arratia
(ed.). Contributions of Southern South America to Vertebrate Paleontology. M�nchner
Geowissenschaftliche Abhandlungen (A). 30, 203-244.
Lamb, 1997. Marsh was right: Ichthyornis had a beak! Journal of Vertebrate
Paleontology. 17(3), 59A.
Chinsamy, Martin and Dodson, 1998. Bone microstructure of the diving Hesperornis
and the volant Ichthyornis from the Niobrara Chalk of western Kansas.
Cretaceous Research. 19(2), 225-233.
Clarke, 1999. New information on the type material of Ichthyornis: Of
chimeras, characters and current limits of phylogenetic inference. Journal of
Vertebrate Paleontology. 19(3), 38A.
Hilton, Gohre, Embree and Stidham, 1999. California's first fossil evidence
of Cretaceous winged vertebrates. California Geology. 52(4), 4-10.
Clarke, 2000. Ichthyornis and Apatornis reappraised. 5th International
Meeting of the Society of Avian Paleontology and Evolution and the Symposium
on Jehol Biota. Vertebrata PalAsiatica. 38(suppl.), 9.
Clarke and Chiappe, 2001. A new carinate bird from the Late Cretaceous of Patagonia
(Argentina). American Museum Novitates. 3323, 1-23.
Elzanowski, Paul and Stidham, 2001. An avian quadrate from the Late Cretaceous
Lance Formation of Wyoming. Journal of Vertebrate Paleontology. 20(4), 712-719.
Chiappe, 2002. Basal bird phylogeny: Problems and solutions. In Chiappe and
Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 448-472.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds).
Mesozoic birds: Above the heads of dinosaurs. Berkeley: University of California
Press. 339-388.
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A case study of alpha taxonomic practice in a phylogenetic frame. Journal of
Vertebrate Paleontology. 23(3), 41A.
Everhart, online 2003-2012. http://www.oceansofkansas.com/Ichthyornis.html
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Burnham and Hines, 2005. Transfer preparation of an Ichthyornis specimen
from the Niobrara Formation. Journal of Vertebrate Paleontology. 25(3), 41A.
Porras-Muzquiz, Chatterjee and Lehman, 2014. The carinate bird Ichthyornis
from the Upper Cretaceous of Mexico. Cretaceous Research. 51, 148-152.
Caggiano and Witmer, 2016. The anatomy of the nasal salt gland of
extant birds and its relevance for inferring the behavior and habitat
preferences of extinct birds and other archosaurs. Journal of
Vertebrate Paleontology. Program
and Abstracts, 108.
Dumont, Tafforeau, Bertin, Bhullar, Field, Schulp, Strilisky,
Thivichon-Prince, Viriot and Louchart, 2016. Synchrotron imaging of
dentition provides insights into the biology of Hesperornis and Ichthyornis, the "last" toothed birds. BMC Evolutionary Biology. 16:178.
Maltese, online 2017. The Accidental Ichthyornis. RMDRC paleo lab. 1-13-2017.
Field, Hanson, Burnham, Wilson, Super, Ehret, Ebersole and Bhullar, 2018. Complete Ichthyornis skull illuminates mosaic assembly of the avian head. Nature. 557, 96-100.
I. sp. (Cumbaa and Tokaryk, 1993)
Middle Cenomanian, Late Cretaceous
Carrot River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Material- ?(RSM P2077.71) radius (Tokaryk et al., 1997)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
(RSM P2626.9) humerus (Sanchez, 2010)
(RSM P2831.3) proximal humerus (Sanchez, 2010)
(RSM P2988.8) humerus (Sanchez, 2010)
?(RSM P2988.15) vertebra (Sanchez, 2010)
Comments- Cumbaa and Tokaryk (1993) mentioned two ichthyornithids from
the Ashville Formation of Saskatchewan, which were later described by Tokaryk
et al. (1997) as Ichthyornis species A (RSM P2077.11, P2077.67, P2077.112
and P2487.5), Ichthyornis species B (RSM P2077.111) and I. sp.
indet. (RSM P2077.71). They referred the specimens to Ichthyornis based
on the coracoid scapular facet being nearly parallel to the sternal end of the
glenoid facet, which Clarke (2004) noted was found in Ichthyornis, but
not apomorphic. Longrich (2009) suggested
the Ashville coracoids did not resemble Ichthyornis, and were referrable
to Pasquiaornis based on their dimorphism (P. hardiei vs. P?
tankei), pachyostosis, and supposed lack of coracoids in the Pasquiaornis
material. Sanchez (2010) confirms the coracoids are Pasquiaornis. The identity of RSM P2077.71 is unresolved.
Cumbaa et al. (2006) mention Ichthyornis-like bones from the Bainbridge River bed of the same member,
which Sanchez specifies are two humeri and a questionably referred vertebra.
References- Cumbaa and Tokaryk, 1993. Early birds, crocodile tears, and
fish tales: Cenomanian and Turonian marine vertebrates from Saskatchewan, Canada.
Journal of Vertebrate Paleontology. 13(3), 31A-32A.
Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds from Saskatchewan,
Canada: The oldest diverse avifauna known from North America. Journal of Vertebrate
Paleontology. 17(1), 172-176.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Cumbaa, Schr�der-Adams, Day and Phillips, 2006. Cenomanian bonebed faunas
from the northeastern margin, Western Interior Seaway. In Lucas and Sullivan
(eds). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum
of Natural History and Science Bulletin. 35, 139-155.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
I? sp. (Hilton, Gohre, Embree and Stidham, 1999)
Campanian, Late Cretaceous
Chico Formation, California, US
Material- (UCMP 170785) incomplete humerus
Reference- Hilton, Gohre, Embree and Stidham, 1999. California's first
fossil evidence of Cretaceous winged vertebrates. California Geology. 52(4),
4-10.
I? sp.
Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (AMNH 110) sacrum (AMNH online)
I. sp.
Coniacian, Late Cretaceous
Fort Hays Member of the Niobrara Formation,
Kansas, US
Material- (FHSM VP-5516) distal humerus (FHSM online)
I? sp.
Late Cenomanian, Late Cretaceous
Lincoln Member of the Greenhorn Limestone, Kansas, US
Material- ?(FHSM VP-17478) femur (FHSM online)
I? sp.
Late Cenomanian-Early Turonian, Late Cretaceous
Greenhorn Limestone, Kansas, US
Material- ?(FHSM VP-5517) long bone shaft (FHSM online)
Comments- FHSM VP-5517 is catalogued as Ichthyornis sp. at the FHSM, but is too fragmentary to identify past Coelurosauria indet..
I. sp. (Walker, 1967)
Early-Middle Turonian, Late Cretaceous
Pfeifer Shale Member of the Greenhorn Limestone or Fairport Chalk Member of
the Carlile Shale, Kansas, US
Material- (FHSM VP-2139; = FSHM 11285; = SMM 2139) (~240 mm) proximal
carpometacarpus (Walker, 1967)
Comments- Walker (1967) first noted this specimen as "“a fragmentary
wing element of Ichthyornis", and it was later called FSHM 11285
by Martin and Stewart (1982). Clarke (2002, 2004) referred the carpometacarpus
to Ichthyornis based on morphological similarity, and Shimada and Fernandes
(2006) described and illustrated the specimen as Ichthyornis sp..
References- Walker, 1967. Revival of interest in the toothed birds of
Kansas. Kansas Academy of Science, Transactions. 70(1), 60-66.
Martin and Stewart, 1982. An ichthyornithiform bird from the Campanian of Canada.
Canadian Journal of Earth Sciences. 19, 324-327.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Fernandes and Shimada, 2005. A Turonian (Late Cretaceous) bird bone from Kansas.
6th Annual Kansas Academy of Science Paleontology Symposium, Abstracts.
Shimada and Fernandes, 2006. Ichthyornis sp. (Aves: Ichthyornithiformes)
from the lower Turonian (Upper Cretaceous) of western Kansas. Transactions of
the Kansas Academy of Science. 109(1/2), 21-26.
I. sp.
Cretaceous
Connecticut, US
Material- (FHSM VP-2210) partial skeleton (FHSM online)
I? sp.
Late Cretaceous?
US
Material- (AMNH 985) proximal scapula, proximal humerus (AMNH online)
Janavis Benito, Kuo, Widrig, Jagt and Field, 2022
J. finalidens Benito, Kuo, Widrig, Jagt and Field, 2022
Late Maastrichtian, Late Cretaceous
CBR-Romontbos Quarry 61H-45, Valkenburg Member of the Maastricht Formation, Belgium
Holotype-
(NHMM/RD 271) (1.50 kg) pterygoid, tooth (4.90x2.80x1.23 mm), partial
fourth cervical vertebra, fifth cervical vertebra, sixth cervical
vertebra, seventh cervical vertebra, eighth cervical vertebra, partial
ninth cervical vertebra, first dorsal vertebra,
incomplete second dorsal vertebra, incomplete third dorsal vertebra,
incomplete fourth dorsal vertebra,
incomplete mid dorsal vertebra, partial mid dorsal vertebra, mid dorsal
vertebral fragment, six partial dorsal ribs, scapula, humerus (134.88
mm), phalanx II-1,
proximal
femur, distal pedal phalanx
Diagnosis- (after Benito et
al., 2022) large pneumatic openings in ventral wall of anterior dorsal
central fossae; fenestrated ventrolateral tubercles on fourth dorsal
vertebra; pneumatic dorsal ribs; complete absence of an acromion
process on scapula; much larger size than Ichthyornis.
compared to Ichthyornis-
medial side of the humeral head is flat instead of protruding
proximally; ventral tubercle is more ovoid and dorsoventrally oriented;
shorter deltopectoral crest (31 vs 37-42% of humeral length); dorsal
and ventral rami which surround pneumotricipital fossa are be more
distinct (taphonomic?); craniocaudally narrower manual
phalanx II-1.
Comments-
Discovered in 2000, Dyke et al. (2002) described this specimen as
Ornithurae indet. based on the globular humeral head, and assigned it
to
Carinatae based on the prominent brachial fossa. Clarke (2004)
considered it Avialae incertae sedis because free proximal tarsals are
generally absent in adult euornithines, but the supposed tarsal was
misidentified. Dumont et al. (2016) found it was "positively
identifiable as either belonging to Ichthyornis sp., or to a closely related taxon within the Ichthyornithiformes" based on studies of the
tooth.
Benito et al. (2020, 2022) CT scanned the specimen and recognized five
cervical vertebrae, five more dorsal vertebrae, manual phalanx II-1,
the rest of the scapula, proximal femur and a pedal phalanx in addition
to what Dyke et al. reported. Benito et al (2022) report "the
reported lower jaws, partial jugals and a possible quadrate all
correspond to a portion of the thorax comprising two thoracic vertebrae
and six associated ribs", the supposed proximal coracoid was
reidentified as a pterygoid, "The reported partial right ulna instead
corresponds to the caudal end of the right scapular blade", the
proximal tarsal "most probably corresponds to a partial pedal phalanx"
and "A reported tarsometatarsus also appears to be absent."
The authors added NHMM/RD 271 to Clarke's and O'Connor's bird matrices
and recovered it as an ichthyornithine.
References- Dyke, Chiappe, Dortangs, Jagt and Schulp, 2002. A new ornithurine
bird from the Maastricht Formation of Belgium; Was there a bottleneck in avian
diversity at the end of the Cretaceous? Journal of Vertebrate Paleontology.
22(3), 50A.
Dyke, Dortangs, Jagt, Mulder, Schulp and Chiappe, 2002. Europe’s last Mesozoic
bird. Naturwissenshaften. 89, 408-411.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Dumont, Tafforeau, Bertin, Bhullar, Field, Schulp, Strilisky,
Thivichon-Prince, Viriot and Louchart, 2016. Synchrotron imaging of
dentition provides insights into the biology of Hesperornis and Ichthyornis, the "last" toothed birds. BMC Evolutionary Biology. 16:178.
Benito, Jagt and Field, 2020. Reinvestigating the 'Maastricht
ichthyornithine' from the latest Cretaceous of Belgium. The Society of
Vertebrate Paleontology 80th
Annual Meeting, Conference Program. 73.
Benito, Kuo, Widrig, Jagt and Field, 2022. Cretaceous ornithurine
supports a neognathous crown bird ancestor. Nature. 612, 100-105.
unnamed possible ichthyornithine (Zelenkov, Averianov and Kurochkin, 2017)
Middle Cenomanian, Late Cretaceous
Middle Member of Melovatka Formation, Russia
Material- (PIN 5554/1) distal tibiotarsus (6.1 mm trans)
Comments- Discovered in 1997,
Zelenkov et al. (2017) assign this to ?Ichthyornithidae indet..
However while it is generally similar to Ichthyornis,
the authors fail to describe any uniquely shared characters and their
phylogenetic analysis (using O'Connor's avialan matrix) recovers it in
a polytomy with other euornithines more derived than Archaeorhynchus and outside Songlingornithidae, Hongshanornithidae, Hesperornithes and Carinatae.
Reference- Zelenkov, Averianov
and Kurochkin, 2017. An Ichthyornis-like bird from the earliest Late
Cretaceous (Cenomanian) of European Russia. Cretaceous Research. 75,
94-100.
Hesperornithes Furbringer, 1888
Definition- (Hesperornis regalis <- Ichthyornis dispar, Passer domesticus) (suggested)
Other definition- (Hesperornis regalis <- Passer domesticus)
(Sereno, online 2005; modified from Clarke, 2004)
= Odontolcae Marsh, 1875a
Definition- (Teeth set in grooves as in Hesperornis regalis) (Martyniuk,
2012)
= Odontognathes Marsh, 1880
= Dromaeopappi Stejneger, 1885
= Odontoholcae Stejneger, 1885
= Enaliornithes Furbringer, 1888
= Hesperornithomorphi Hay, 1930
Other diagnoses- Marsh (1875a, b) diagnosed his new taxon Odontolcae
based on several characters. Teeth set in grooves are found in Hesperornis, Parahesperornis and Pasquiaornis, but are unknown
in Enaliornis. All presacral vertebrae being heterocoeliys is not true in Pasquiaornis. The keelless sternum is present in Hesperornis
and probably Fumicollis but still unknown for more basal genera, while
the reduced forelimb is present at least as early as Pasquiaornis, but
unknown in Enaliornis.
Comments- Marsh (1875a) named Odontolcae as an order including Hesperornis
but not Ichthyornis. Martyniuk (2012) gave it an apomorphy-based definition,
which could apply to all hesperornithines or only taxa as derived as Pasquiaornis given the lack of information for Enaliornis. Stejneger (1885) modified it to be the subclass Odontoholcae,
and named the order Dromaeopappi.
Romer (1933) placed Eupterornis from the Paleocene of France in Baptornithidae,
but is was reassigned to Gaviiformes by Brodkorb (1963). Brodkorb (1963) placed
Neogaeornis
in in Baptornithidae, but it was placed in Gaviiformes by Olson (1992)
and has more recently been assigned to Vegaviidae by Agnolin et al.
(2017). Nessov (1992) had identified KKM KP 4925/P131 as the incomplete
humerus of a hesperornithine, but later (in Mourer-Chauvire, 1992)
determined it was a mosasaur limb element. Longrich (2006) stated the
dorsal vertebra TMP 1989.081.0012 from the Dinosaur Park Formation of
Alberta was a possible hesperornithine, but later (2009) referred it to
Palintropus sp.. Dyke et al. (2011) referred
a supposed distal femur (MTCO 17637) from the Cornet bauxite of Romania to Hesperornithes
(earlier listed as isolated bones similar to Enaliornis by Galton et
al., 2009), but Agnolin and Varricchio (2012) believe it is more similar to
an azhdarchid proximal radius.
References- Marsh, 1872. Preliminary description of Hesperornis regalis,
with notices of four other new species of Cretaceous birds. American Journal
of Science, 3rd series. 3, 359-365.
Marsh. 1875a. On the Odontornithes, or birds with teeth. American Journal of
Science, Series 3. 10(59), 403-408.
Marsh, 1875b. Odontornithes, or birds with teeth. The American Naturalist. 9(12),
625-631.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Stejneger, 1885. Birds. in Kingsley (ed). The Standard Natural History. Volume
4.
Furbringer, 1888. Untersuchungeb zur Morphologie und Systematik der Vogel. Amsterdam:
Holkema. 1751 pp.
Shufeldt, 1890. On the affinities of Hesperornis. Nature. 43, 176.
Thompson, 1890. On the systematic position of Hesperornis. Studies from
the Museum of Zoology. 1(10), 15 pp.
Anonymous, 1891. Professor Thompson on the systematic position of Hesperornis.
Auk. 8(3), 304-305.
Helm, 1891. On the affinities of Hesperornis. Nature. 43, 368.
Marsh, 1897. The affinities of Hesperornis. Nature. 55, 534.
Hay, 1930. Second bibliography and catalogue of the fossil vertebrata of North
America, Volume 2. Carnegie Institution of Washington Publication, 390, 1074
pp.
Romer, 1933. Vertebrate Paleontology. University of Chicago Press, Chicago.
Brodkorb, 1963. Catalogue of fossil birds. Part 1 (Archaeopterygiformes through
Ardeiformes). Bulletin of the Florida State Museum, Biological Sciences. 7, 179-293.
Mourer-Chauvire, 1992. Society of Avian Paleontology and Evolution Information
Newsletter. 6.
Nessov, 1992. Review of localities and remains of Mesozoic and Paleogene birds
of the USSR and the description of new findings. Russkii Ornitologicheskii Zhurnal.
1(1), 7-50.
Olson, 1992. Neogaeornis wetzeli Lambrecht, a Cretaceous loon from Chile
(Aves: Gaviidae). Journal of Vertebrate Paleontology. 12, 122-124.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Sereno, online 2005. Stem Archosauria - TaxonSearch. http://www.taxonsearch.org/dev/file_home.php
[version 1.0, 2005 November 7]
Hinic-Frlog and Motani, 2006. Correlation of osteology and locomotion: Inferring
swimming modes in extinct Ornithurae. Journal of Vertebrate Paleontology. 26(3),
76A.
Longrich, 2006. An ornithurine bird from the Late Cretaceous of Alberta, Canada.
Canadian Journal of Earth Sciences. 43(1), 1-7.
Bell, Tseng and Chiappe, 2008. Diving mechanics of the extinct Hesperornithiformes:
Comparison to modern diving birds. Journal of Vertebrate Paleontology. 28(3),
50A.
Galton, Dyke and Kurochkin, 2009. Re-analysis of Lower Cretaceous fossil birds
from the UK reveals an unexpected diversity. Journal of Vertebrate Paleontology.
29(3), 102A.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Dyke, Benton, Posmosanu and Naish, 2011. Early Cretaceous (Berriasian) birds
and pterosaurs from the Cornet bauxite mine, Romania. Palaeontology. 54(1),
79-95.
Wilson, 2011. The feeding ecology of Cretaceous and modern pursuit diving birds.
Journal of Vertebrate Paleontology. Program and Abstracts 2011, 215.
Agnolin and Varricchio, 2012 . Systematic reinterpretation of Piksi barbarulna
Varricchio, 2002 from the Two Medicine Formation (Upper Cretaceous) of Western
USA (Montana) as a pterosaur rather than a bird. Geodiversitas. 34(4), 883-894.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Bell, 2013. Evolution & ecology of Mesozoic birds: A case study of the derived
Hesperornithiformes and the use of morphometric data in quantifying avian paleoecology.
PhD thesis. University of Southern California. 390 pp.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Agnol�n, Briss�n Egli, Chatterjee, Garcia Mars� and Novas, 2017.
Vegaviidae, a new clade of southern diving birds that survived the K/T
boundary. The Science of Nature. 104(11), id.87.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
= "Brachydontornis" O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021 online
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021 online
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
= "Brachydontornis zhangi" O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021 online
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2021 online
Late Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Material-
(IVPP V26197) predentary, dentaries, basihyal or urohyal?, hyoids (12.3
mm), ?axis, ?third cervical vertebra (4.65 mm), ?fourth cervical
vertebra (4.63 mm), ?fifth cervical vertebra, ?sixth cervical vertebra,
?seventh cervical vertebra, ?eighth cervical vertebra (6.06 mm), ?ninth
cervical vertebra, two cervicodorsal vertebrae, two dorsal vertebrae,
pellet (8.3x6.3 mm)
Diagnosis- (after O'Connor et
al., 2022) predentary present; dentary teeth located in communal
groove with interdental plates absent; teeth short, approximately equal
in crown height and FABL; dentary teeth closely spaced, separated by a
distance less than half their FABL.
Differs from other hesperornithines in- smaller size; dentary teeth
shorter, straighter and blunter; shorter dentary tooth row with fewer
teeth.
Comments- Discovered in 2004 or 2005, this was first mentioned and figured as an undescribed specimen of Gansus
in the supplementary information of Bailleul et al. (2019).
O'Connor et al. (2021) presented it at an SVP
presentation as a new taxon "Brachydontornis zhangi", mentioned in the
abstract as that specimen with "blunt, relatively low-crowned teeth
placed in a communal groove". It was named
and described by O'Connor et al. (2021 online) as "Brevidentavis
zhangi", but the paper has no
mention of ZooBank or an entry on the ZooBank
webite. Thus according to ICZN Article 8.5.3 (an electronic work
must "be registered in the Official Register of Zoological Nomenclature
(ZooBank) (see Article 78.2.4) and contain evidence in the work itself
that such registration has occurred"), "Brevidentavis zhangi" O'Connor
et al.,
2021 was a nomen nudum until September 2022. Interestingly, "Branchydontornis
zhangi" was used in the graphical abstract, tables 1 and 2 and figure
9 of the Early View version of the paper. Creisler (DML 2021) revealed he had suggested both names (the
other as "Brachyodontornis") and "The authors went with Brevidentavis
as the formal name, but the earlier contemplated name apparently was
not caught in editing."
O'Connor et al. (2021, 2022) added it to O'Connor's bird matrix
and recovered it in a polytomy of hesperornithines. Note the trees
in their figure are majority rule and implied weighting. Adding it to
Hartman et al.'s maniraptoromorph analysis results in a sister group
relationship with Parahesperornis,
although other positions in Hesperornithidae are only one step longer,
and other positions in Hesperornithes are two steps longer.
O'Connor et al. (2022) say "Given the differences in dental and
dentary morphology and the absence of any postcranial remains that
could further support this placement, we do not consider Brevidentavis
IVPP V26197 to be a hesperornithiform at this time", but while a
relationship with the later and deeply nested Parahesperornis itself seems unlikely, the smaller basal hesperornithine Enaliornis is almost contemporaneous. Thus a hesperornithine identity may yet be plausible.
References- Bailleul, Li,
O'Connor and Zhou, 2019. Origin of the avian predentary and evidence of
a unique form of cranial kinesis in Cretaceous ornithuromorphs.
Proceedings of the National Academy of Sciences. 116(49), 24696-24706.
O'Connor, Lamanna, Harris, Hu, Bailleul, Wang and You, 2021. First
avian skulls from the Lower Cretaceous Xiagou Formation, Gansu, China.
The Society of
Vertebrate Paleontology Virtual Meeting Conference Program, 81st Annual
Meeting. 196.
O'Connor, Stidham, Harris, Lamanna, Bailleul, Hu, Wang and You, 2022
(online 2021). Avian skulls represent a diverse ornithuromorph fauna
from the
Lower Cretaceous Xiagou Formation, Gansu Province, China. Journal of
Systematics and Evolution. 60(5), 1172-1198.
unnamed hesperornithine (Longrich, 2009)
Late Campanian, Late Cretaceous
Upper Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1986.112.0006; Ornithurine A) proximal coracoid
Diagnosis- (after Longrich, 2009) large size; humeral articular facet
placed anterolaterally with respect to scapular cotyle; shallow scapular cotyle;
coracoid shaft massive and posteriorly bowed.
Comments- Longrich (2009) suggested the shallow scapular cotyle, massive
shaft, and dorsally bowed shaft were similar to coracoids from the Ashville
Formation of Saskatchewan which were originally referred to Ichthyornis spp.,
but which proved to be Pasquiaornis.
Agnolin (2010) suggested it was a cimolopterygid, but Mohr et al.
(2021) correctly noted it lacks his proposed characters for the family-
distally extensive procoracoid process; distally placed and enlarged
supracoracoid foramen; laterally angled glenoid.
References- Longrich, 2009. An ornithurine-dominated avifauna from the
Belly River Group (Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous
Research. 30(1), 161-177.
Agnolin, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina.
Studia Geologica Salmanticensia. 46(2), 99-119.
Mohr, Acorn, Funston and Currie, 2021 (2020 online). An ornithurine bird coracoid from the Late Cretaceous of Alberta, Canada. Canadian Journal of Earth Sciences. 58(2), 134-140.
undescribed Hesperornithes (Sanchez, 2010)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Material-
(RSM P2626.17) vertebra
(RSM P2626.28) carpometacarpus (50.6 mm)
(RSM P2626.38) distal tarsometatarsus
(RSM P2831.17) proximal radius
(RSM P2987.9) distal tibiotarsus
(RSM P2987.19) synsacrum
?(RSM P2997.37) cranial or pelvic element
(RSM P2997.39) distal tibiotarsus
(RSM P2997.49) distal tibiotarsus
(RSM P2997.57) synsacrum
(RSM P2997.61) proximal dorsal rib
Comments- These are listed as hesperornithiform by Sanchez (2010), so may be Pasquiaornis or his unnamed hesperornithoid. RSM P2997.37 is listed as "unknown skull piece, may be part of pelvis."
Reference- Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Hesperornithes indet. (Hanks and Shimada, 2002)
Middle-Late Turonian, Late Cretaceous
Carlile Shale, South Dakota, US
Material- (SMM P2001.12.10) (~900 mm) partial tibiotarsus
Comments- Hanks and Shimada
(2002) first mentioned in an abstract that "the surface of one of the
bird bones (possibly the distal 1/3 of a tibiotarsus of a
hesperornithiform) has multiple tooth marks (with clear serration
grooves) of the Late Cretaceous shark, Squalicorax sp.". It was later described in detail by Hanks and Shimada (2020).
References- Hanks and Shimada,
2002. Vertebrate fossils, including non-avian dinosaur remains and the
first shark-bitten bird bone from a Late Cretaceous (Turonian) marine
deposit of northeastern South Dakota. Journal of Vertebrate
Paleontology. 22(3), 62A.
Shimada and Hanks, 2020. Shark-bitten hesperornithiform bird bone from
a Turonian (Upper Cretaceous) marine deposit of northeastern South
Dakota, U.S.A.. Transactions of the Kansas Academy of Science.
123(3-4), 414-418.
undescribed Hesperornithes (Kirkland et al., 1997)
Late Albian, Early Cretaceous
Mussentuchit Member of the Cedar Mountain Formation, Utah, US
Material- many teeth
Comments- Kirkland et al. (1997) listed Hesperornithiformes indet., while
Cifelli et al. (1999) noted two Avialae dental morphs, one referrable to Hesperornithiformes.
They described the latter specimens as having bulbous bases and rare serrations.
References- Kirkland, Britt, Burge, Carpenter, Cifelli, DeCourten, Eaton,
Hasiotis and Lawton, 1997. Lower to Middle Cretaceous dinosaur faunas of the
Central Colorado Plateau: a key to understanding 35 million years of tectonics,
sedimentology, evolution, and biogeography. Brigham Young University Geology
Studies. 42, 69-103.
Cifelli, Nydam, Gardner, Weil, Eaton, Kirkland, Madsen, 1999. Medial Cretaceous
vertebrates from the Cedar Mountain Formation, Emery County, Utah: the Mussentuchit
Local Fauna. in Gillette (ed.). Vertebrate Paleontology in Utah. Utah Geological
Survey, Miscellaneous Publication. 99-1, 219-242.
undescribed hesperornithine (Mourer-Chauvire, 1991)
Maastrichtian, Late Cretaceous
Zhuravlovskaya Svita (not Eginsaiskaya Svita), Kazakhstan
Material- (ZIN PO coll.) tibiotarsal shaft, distal tibiotarsi (Nessov
in Chauvire-Mourer, 1991)
Comments- Nessov (in Mourer-Chauvire, 1991) first mentioned two hesperornithine
tibiotarsi from this locality, which may be this material. Nessov (in Mourer-Chavire,
1992) mentioned small hesperornithine material slightly larger than Baptornis
advenus and referred to Baptornithidae, but not Baptornis itself
because "of the peculiar structure of the fossa on the tibiotarsus, related
to the side of the foramen interosseum proximale, and because the crista fibularis
is not so strongly turned behind as in Baptornis, and much weaker."
Nessov and Yarkov (1993) reported these as Baptornithidae indet., and Nessov
(1997) commented on small hesperornithine material, some of which he thought
was possibly referrable to Baptornis. Panteleev et al. (2004) thought
this was possibly based on juvenile specimens of Asiahesperornis, while
Dyke et al. (2006) thought it "probably pertains to a smaller hesperornithiform
taxon, an area for future work." As the traditional Baptornithidae is paraphyletic
and there is no evidence the Zhuravlovskaya tibiotarsi are more closely related
to Baptornis than to Hesperornis, they are here placed as Hesperornithes
incertae sedis.
References- Mourer-Chauvire, 1991. Society of Avian Paleontology and
Evolution Information Newsletter. 5.
Mourer-Chauvire, 1992. Society of Avian Paleontology and Evolution Information
Newsletter. 6.
Nessov and Yarkov, 1993. [Hesperornithes in Russia] Russkii Ornitolocheskii
Zhurnal. 2(1), 37-54.
Nessov, 1997. Cretaceous non-marine vertebrates of Northern Eurasia. St. Petersburg
State University, St-Petersburg. 218 pp.
Panteleev, Popov and Averianov, 2004. New record of Hesperornis rossicus
(Aves, Hesperornithiformes) in the Campanian of Saratov Province, Russia. Paleontological
Research. 8(2), 115-122.
Dyke, Malakhov and Chiappe, 2006. A re-analysis of the marine bird Asiahesperornis
from northern Kazakhstan. Cretaceous Research. 27(6), 947-953.
unnamed Hesperornithes (Kurochkin, 1988)
Late Campanian-Early Maastrichtian, Late Cretaceous
Gurilin Tsav,
Nemegt Formation, Mongolia
Material- cervical vertebra (Kurochkin, 1995)
Late Campanian-Early Maastrichtian, Late Cretaceous
Tsaagan Khushu,
Nemegt Formation, Mongolia
(IGM 100/1311) distal tibiotarsus (12.1 mm wide) (Clarke and
Norell, 2004)
distal tibiotarsus (11.7 mm wide) (Kurochkin, 1988)
partial mandible (Kurochkin, 2000)
Comments- Kurochkin (1988) identified a distal tibiotarsus as Baptornis
sp., and later (1995, 2000) as closer to Parahesperornis. Clarke and Norell
(2004) described a similar specimen and referred both to nonavian ornithurines
(sensu Gauthier and de Queiroz), though they did note characters were shared
with Baptornis while Kurochkin's Parahesperornis-like characters
were disputed. They were skeptical of referring isolated Cretaceous diving euornithine
specimens to Hesperornithines, though no reasons were given for removing any
of it from that clade, and it seems most parsimonious to assume a single clade
of Mesozoic taxa with hesperornithine-like limbs until shown otherwise. The
elements are more similar to Enaliornis? seeleyi than Baptornis
in the anteriorly rounded lateral condyle in distal view, though the anterior
intercondylar sulcus is narrower as in Baptornis. The medial projection
of the medial condyle is intermediate between the two taxa, while the extensor
groove extends less distally than in both.
Kurochkin (2000) mentioned "two further remains (a cervical vertebra
and the portion of a mandible) representing small hesperornithiforms
were collected by the JRMPE in the Nemegt Beds of Guriliin Tsav and
Tsagaan Khushuu" which were "somewhat different" from other
hesperornithines. The order of localities matches the order of
materials as shown by Kurochkin (1995) who mentioned a "Gurileen Tsav
(vertebra)." He referred these to "Hesperornithiformes fam. nov."
along with the then unnamed holotype of Brodavis mongoliensis from Bugin Tsav though he did not list any diagnostic characters.
References- Kurochkin, 1988. [Cretaceous birds of Mongolia and their
significance for study of the phylogeny of class Aves.] Trudy Sovmestnoi Sovetsko-Mongolskoi
Paleontologicheskoi Ekspeditsii. 34, 33-42.
Kurochkin, 1995. The assemblage of the Cretaceous birds in
Asia. In Sun and Wang (eds.). Sixth Symposium on Mesozoic Terrestrial Ecosystems
and Biota, Short Papers. 203-208.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Clarke and Norell, 2004. New avialan remains and a review of the known avifauna
from the Late Cretaceous Nemegt Formation of Mongolia. American Museum Novitates.
3447. 12 pp.
unnamed hesperornithine (Tanaka, Kobayashi, Ikuno, Ikeda and Saegusa, 2020)
Early Maastrichtian, Late Cretaceous
Kita-ama Formation, Hyogo, Japan
Material- (MNHAH D1-048531) (juvenile) (tibiotarsus 153.43 mm) tibia, incomplete astragalocalcaneum
Comments- This was discovered in August 2004 and considered by Tanaka et al. (2020) to be a non-hesperornithid hesperornithine.
Reference- Tanaka, Kobayashi,
Ikuno, Ikeda and Saegusa, 2020. Marine hesperornithiform (Avialae:
Ornithuromorpha) from the Maastrichtian of Japan: Implications for the
paleoecological diversity of the earliest diving birds in the end of
the Cretaceous. Cretaceous Research. 113, 104492.
unnamed hesperornithine (Agnolin and Martinelli, 2009)
Campanian-Maastrichtian, Late Cretaceous
Los Alamitos Formation, Rio Negro, Argentina
Material- (MACN PV RN 1114) distal tibia
Reference- Agnolin and Martinelli, 2009. Fossil birds from the Late Cretaceous
Los Alamitos Formation, R�o Negro province, Argentina. Journal of South
American Earth Sciences. 27, 42-49.
undescribed Hesperornithes (Mourer-Chauvire, 1992)
Early Cretaceous
Antarctica
Comments-
Mourer-Chauvire (1992) reported that after October 1992 "Hou will be
busy studying Early Cretaceous Hesperornithiformes from the Antarctic",
though these have yet to be described.
Reference- Mourer-Chauvire, 1992. Society of Avian Paleontology and Evolution
Information Newsletter. 6, 7.
Hesperornithiformes Sharpe, 1899
Definition- (Hesperornis regalis + Enaliornis barretti)
(Martyniuk, 2012)
References- Sharpe, 1899. A hand-list of the genera and species of birds.
Vol. I. London. British Museum (Natural History).
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Pasquiaornis Tokaryk, Cumbaa and Storer, 1997
Other diagnoses- Tokaryk et al. (1997) used the less laterally projected
trochanteric crest and less mediolaterally expanded proximal femur to distinguish
Pasquiaornis from Baptornis, but this is primitive and also found
in Enaliornis and Ichthyornis. The intercotylar prominence is
anteriorly positioned and overhangs the shaft in Hesperornis and Parahesperornis
as well. The trochlea of metatarsal II is posterior to and close to the base
of trochlea III in all hesperornithines.
Comments- Both of these species were only briefly described and illustrated
by Tokaryk et al. (1997), and not compared to the similar Enaliornis.
This leaves them without a valid published diagnosis, nor are any characters known which
could group them together to the exclusion of more derived hesperornithines. To the contrary,
the larger size and metatarsal IV trochlear neck which is placed dorsal to that
on trochlea III are characters which P? tankei shares with Baptornis
and hesperornithids to the exclusion of P. hardiei. However, officially
removing tankei from Pasquiaornis should not be done until the
material of both hardiei and tankei
is examined in detail, including the Bainbridge River specimens. Bell
and Chiappe (2016) found both species to score identically in their
matrix, and emerge basal to Enaliornis,
but noted most material was unavailable for study. More recently
Tanaka et al. (2018) gained access to the Bainbridge River material and
recovered Pasquiaornis (scored as a single OTU) closer to hesperornithoids than Enaliornis
(also a single OTU) based on three unambiguous characters, which also
matches stratigraphically. Sanchez (2010) has described the
Bainbridge River material in his thesis.
References- Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds
from Saskatchewan, Canada: the oldest diverse avifauna known from North America.
Journal of Vertebrate Paleontology. 17(1), 172-176.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Tanaka, Kobayashi, Kurihara, Fiorillo and Kano, 2018 (online 2017). The
oldest Asian hesperornithiform from the Upper Cretaceous of Japan, and
the phylogenetic reassessment of Hesperornithiformes. Journal of
Systematic Palaeontology. 16(8), 689-709.
P. hardiei Tokaryk, Cumbaa and
Storer, 1997
Middle Cenomanian, Late Cretaceous
Carrot River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Holotype- (RSM P2077.117) tarsometatarsus (54 mm)
Paratype- (RSM P2077.60) femur (47.5 mm)
Referred- (RSM P2077.11) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.62) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.67) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.110) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.111) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.112) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
?(RSM P2077.125) (juvenile) distal tarsometatarsus (Tokaryk, Cumbaa and Storer,
1997)
(RSM P2409.1) proximal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2409.9) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2409.11) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2409.49) distal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
?(RSM P2487.3) distal humerus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2487.7) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
(RSM P2526.4) partial dentary
(RSM P2626.18) anterior synsacrum
(RSM P2626.20; mislabeled in Appendix I of Sanchez, 2010 as RSM P2626.2) distal tibiotarsus
(RSM P2626.31) distal tarsometatarsus
(RSM P2626.33) distal tarsometatarsus
(RSM P2626.35) distal femur
(RSM P2626.37) distal femur
(RSM P2626.40) distal tibiotarsus
(RSM P2626.41) proximal fibula
(RSM P2830.1) proximal tarsometatarsus
(RSM P2830.2) distal tarsometatarsus
(RSM P2830.4) proximal tibiotarsus
(RSM P2831.1) proximal femur
(RSM P2831.6) anterior dentary
(RSM P2831.7) partial dorsal vertebra (10.0 mm)
(RSM P2831.8) ~twelfth-thirteenth cervical vertebra (14.8 mm)
(RSM P2831.12) partial synsacrum
(RSM P2831.15) pedal phalanx (17 mm)
(RSM P2831.16) pedal phalanx (14.4 mm)
(RSM P2831.18) partial angular
(RSM P2831.21) splenial
(RSM P2831.23) tooth
(RSM P2831.54) distal coracoid
(RSM P2957.6) distal tarsometatarsus
(RSM P2957.12) frontal
(RSM P2957.13) distal tibiotarsus
(RSM P2957.14) distal tibiotarsus
(RSM P2957.29) partial pelvis
(RSM P2985.2) dorsal vertebra (12.0 mm)
(RSM P2985.5) pedal phalanx (18.8 mm)
(RSM P2985.6) distal tarsometatarsus
(RSM P2985.8) proximal scapula
(RSM P2985.9) partial splenial
(RSM P2987.1) tarsometatarsus (56.5 mm)
(RSM P2987.21) proximal scapula
(RSM P2987.26) proximal radius
(RSM P2988.1) proximal femur
(RSM P2988.3) distal tarsometatarsus
(RSM P2988.17) partial pelvis
(RSM P2988.19) angular
(RSM P2988.21) proximal fibula
(RSM P2988.27) splenial
(RSM P2989.2) proximal tarsometatarsus
(RSM P2989.3) distal tarsometatarsus
(RSM P2989.4) distal tarsometatarsus
(RSM P2989.6) distal tarsometatarsus
(RSM P2989.8) proximal tarsometatarsus
(RSM P2989.9) proximal tarsometatarsus
(RSM P2989.15) distal humerus
?(RSM P2989.19) posterior mandible
(RSM P2989.25; mislabeled in Plate XV of Sanchez, 2010 as RSM P2985.25) anterior synsacrum
(RSM P2989.37) angular
(RSM P2989.39) pelvis
(RSM P2989.40) pedal phalanx
(RSM P2995.3) proximal ulna
(RSM P2995.7) proximal tibiotarsus
(RSM P2997.4) femur (50.7 mm)
(RSM P2997.9) distal femur
(RSM P2997.10) femur (49.9 mm)
(RSM P2997.12) femur (48.2 mm)
(RSM P2997.14) distal femur
(RSM P2997.15) tarsometatarsus (51.9 mm)
(RSM P2997.16) proximal tarsometatarsus
(RSM P2997.18) tarsometatarsus (60.8 mm)
(RSM P2997.19) proximal tarsometatarsus
(RSM P2997.20) distal tarsometatarsus
(RSM P2997.22) proximal tarsometatarsus
(RSM P2997.27) proximal ulna
(RSM P2997.28) proximal ulna
(RSM P2997.29) distal ulna
(RSM P2997.36) frontal
(RSM P2997.40) distal tibiotarsus
(RSM P2997.41) distal tibiotarsus
(RSM P2997.42) distal tibiotarsus
(RSM P2997.46) proximal tibiotarsus
(RSM P2997.47) distal tibiotarsus
(RSM P2997.48) distal tibiotarsus
(RSM P2997.62) partial pelvis
(RSM P2997.63) pelvic fragment
(RSM P2997.69) pedal phalanx (20.1 mm)
(RSM P2997.74) incomplete radius (58.3 mm)
(RSM P2997.75) incomplete radius
(RSM P2997.76) angular
(RSM P2997.79) proximal femur
(RSM P2997.81) proximal tarsometatarsus
(RSM P2997.83) proximal tarsometatarsus
(RSM P3015.1) proximal femur
(RSM P3015.2) proximal femur
(RSM P3015.3) proximal femur
(RSM P3015.10) proximal radius
(RSM P3015.14) distal pedal phalanx
(RSM P3015.18) distal tarsometatarsus
Diagnosis- (after Tokaryk et al., 1997) smaller than P? tankei.
Other diagnoses- Tokaryk et al. (1997) say the medial tarsometatarsal
cotyle is "deflected toward shaft", but those of most hesperornithines
are angled somewhat as well. The neck of trochlea III being higher anteriorly
than that of trochlea IV is primitive, being present in Enaliornis barretti
and E? seeleyi as well. The "distal rim" of the femoral head
is said to be perpendicular to the shaft, but this does not appear to be true
for either the rim of the articular surface or the medial or ventral edges of
the head.
Comments-
Excavated in 1992 and 1993, this was first noted as a new species of
baptornithid by Cumbaa and Tokaryk (1993) before being described by
Tokaryk et al. (1997). Tokaryk et al. (1997) reported that in
1994 and 1995 numerous bird fossils similar to Pasquiaornis were discovered at the Bainbridge
River Bonebed. Cumbaa et al. (2006) states hundreds of bird specimens are known,
mostly hesperornithine, and illustrates four teeth. Sanchez et al. (2009) note
both P. hardiei and P? tankei
are represented in this material, which was described by Sanchez
(2010). Type A teeth of Sanchez (2010) are here assigned to P. hardiei because they are larger. Sanchez lists RSMP2989.19 as "small, may be Ichthyornis."
Cumbaa and Tokaryk mentioned two ichthyornithids from
the Ashville Formation of Saskatchewan, which were later described by Tokaryk
et al. (1997) as Ichthyornis species A (RSM P2077.11, P2077.67, P2077.112
and P2487.5), Ichthyornis species B (RSM P2077.111) and I. sp.
indet. (RSM P2077.71). They referred the specimens to Ichthyornis based
on the coracoid scapular facet being nearly parallel to the sternal end of the
glenoid facet, which Clarke (2004) noted was found in Ichthyornis, but
not apomorphic. Tokaryk et al. distinguished species A from species B by its
gracility and round (vs. angular) scapular facet. Longrich (2009) suggested
the Ashville coracoids did not resemble Ichthyornis, and were referrable
to Pasquiaornis based on their dimorphism (P. hardiei vs. P?
tankei), pachyostosis, and supposed lack of coracoids in the Pasquiaornis
material. Sanchez (2010) confirms the coracoids are Pasquiaornis, and Ichthyornis species A is here placed in P. hardiei.
References- Cumbaa and Tokaryk, 1993. Early birds, crocodile tears, and
fish tales: Cenomanian and Turonian marine vertebrates from Saskatchewan, Canada.
Journal of Vertebrate Paleontology. 13(3), 31A-32A.
Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds from Saskatchewan,
Canada: the oldest diverse avifauna known from North America. Journal of Vertebrate
Paleontology. 17(1), 172-176.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Cumbaa, Schr�der-Adams, Day and Phillips, 2006. Cenomanian bonebed faunas
from the northeastern margin, Western Interior Seaway. In Lucas and Sullivan
(eds). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum
of Natural History and Science Bulletin. 35, 139-155.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Sanchez, Cumbaa and Schroder-Adams, 2009. Late Cretaceous (Cenomanian) Hesperornithiformes
from the Pasquia Hills, Saskatchewan, Canada. Journal of Vertebrate Paleontology.
29(3), 175A.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Tanaka, Takasaki and Tokaryk, 2021. Osteological histology of the Cretaceous seabird Pasquiaornis
(Avialae, Hesperornithiformes): Implications for the flight ability of
the basal hesperornithiforms. 2021 Northeast Natural History Conference
Poster Abstracts. 51.
P? tankei Tokaryk, Cumbaa and
Storer, 1997
Middle Cenomanian, Late Cretaceous
Carrot River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Holotype- (RSM P2077.63) incomplete tarsometatarsus (85.6 mm)
Paratype- (RSM P2077.108) femur (64.76 mm)
Referred- (RSM P2077.10) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.72) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.79) distal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.107) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.109) femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.113) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.116) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.118) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.119) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.120) quadrate, distal tibiotarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.123) partial pelvic element (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.124) partial pelvic element (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2077.127) partial pelvic element (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2409.2) proximal tarsometatarsus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2409.3) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2467.2) distal femur (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2467.3) distal femur (Tokaryk, Cumbaa and Storer, 1997)
?(RSM P2467.8) distal humerus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2487.2) femur (Tokaryk, Cumbaa and Storer, 1997)
?(RSM P2487.4) distal humerus (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2487.5) partial coracoid (Tokaryk, Cumbaa and Storer, 1997)
(RSM P2487.8) proximal tibiotarsus (Tokaryk, Cumbaa and Storer, 1997)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
(RSM P2526.2) proximal radius
(RSM P2526.3) proximal radius
(RSM P2626.6) partial pelvis
(RSM P2626.10; mislabeled in Appendix I of Sanchez, 2010 as RSM P2626.1) partial coracoid
(RSM P2626.11) distal coracoid
(RSM P2626.12) frontal
(RSM P2626.15) ~fourth-sixth cervical vertebra (25.7 mm)
(RSM P2626.16) ~fourth-sixth cervical vertebra (23.9 mm)
(RSM P2626.19) pedal phalanx III-2 (24.4 mm)
(RSM P2626.27) partial pelvis
(RSM P2626.29) pelvis
(RSM P2626.30) coracoid (42.8 mm)
(RSM P2626.31) pedal phalanx (22.5 mm)
(RSM P2626.34) distal femur
(RSM P2626.36) proximal femur
(RSM P2626.39) dorsal vertebra (17.8 mm)
(RSM P2626.42) surangular, prearticular
(RSM P2830.3) proximal scapula
(RSM P2831.2) proximal humerus
(RSM P2831.4) proximal carpometacarpus
(RSM P2831.5) dentary
(RSM P2831.9) partial ~fifth-eighth cervical vertebra (18.9 mm)
(RSM P2831.10) partial dorsal vertebra (14.7 mm)
(RSM P2831.11) dorsal vertebra (16.7 mm)
(RSM P2831.20) proximal radius
(RSM P2831.22) tooth
(RSM P2831.24) tooth
(RSM P2831.25) tooth
(RSM P2831.26) tooth
(RSM P2831.27) tooth
(RSM P2831.28) tooth
(RSM P2831.30) tooth
(RSM P2831.31) tooth
(RSM P2831.32) tooth
(RSM P2831.33) tooth
(RSM P2831.34) tooth
(RSM P2831.35) tooth
(RSM P2831.36) tooth
(RSM P2831.37) tooth
(RSM P2831.38) tooth
(RSM P2831.39) tooth
(RSM P2831.40) tooth
(RSM P2831.41) tooth
(RSM P2831.42) tooth
(RSM P2831.43) tooth
(RSM P2831.44) tooth
(RSM P2831.46) tooth
(RSM P2831.47) tooth
(RSM P2831.52) distal quadrate
(RSM P2831.53) pelvis
(RSM P2831.55) incomplete frontal
(RSM P2831.56) proximal scapula
(RSM P2831.57) proximal radius
(RSM P2957.2) coracoid (46.6 mm)
(RSM P2957.5) proximal femur
(RSM P2957.7) proximal humerus
(RSM P2957.9) proximal coracoid
(RSM P2957.10) proximal coracoid
(RSM P2957.15) dorsal vertebra (17.4 mm)
(RSM P2957.16) partial cervical vertebra
(RSM P2957.17) cervical vertebra (11.4 mm)
(RSM P2957.19) proximal scapula
(RSM P2957.21) distal tibiotarsus
(RSM P2957.22) proximal tibiotarsus
(RSM P2957.23) mandible
(RSM P2957.24) distal humerus
(RSM P2957.25) distal humerus
(RSM P2957.26) distal humerus
(RSM P2957.27) tarsometatarsus (81.3 mm)
(RSM P2985.1) dorsal vertebra
(RSM P2985.3) dorsal vertebra (16.0 mm)
(RSM P2985.4) dorsal vertebra
(RSM P2985.7) proximal coracoid
(RSM P2985.10) anterior dentary
(RSM P2986.2) angular
(RSM P2987.2) distal humerus
(RSM P2987.3) distal humerus
(RSM P2987.4) proximal humerus
(RSM P2987.5) proximal coracoid
(RSM P2987.6) distal coracoid
(RSM P2987.7) proximal coracoid
(RSM P2987.8) proximal carpometacarpus
(RSM P2987.10) proximal tibiotarsus
(RSM P2987.13) cervical vertebra (19.5 mm)
(RSM P2987.14) cervical vertebra (17.8 mm)
(RSM P2987.15) cervical vertebra (21.6 mm)
(RSM P2987.16) cervical vertebra (20.0 mm)
(RSM P2987.17) ~fourth-thirteenth cervical vertebra (18.5 mm)
(RSM P2987.18) partial dorsal vertebra (16.9 mm)
(RSM P2987.20) partial anterior synsacrum
(RSM P2987.24) pedal phalanx (25.1 mm)
(RSM P2987.25) proximal radius
(RSM P2988.2) distal femur
(RSM P2988.5) proximal humerus
(RSM P2988.6) proximal humerus
(RSM P2988.7) proximal humerus
(RSM P2988.9) coracoid (50.68 mm)
(RSM P2988.10) surangular
(RSM P2988.11) anterior dentary
(RSM P2988.12) first dorsal or last cervical vertebra (15.0 mm)
(RSM P2988.13) ~fourteenth-fifteenth cervical vertebra
(RSM P2988.14) ~fourteenth-fifteenth cervical vertebra (17.8 mm)
(RSM P2988.16) synsacrum
(RSM P2988.18) proximal radius
(RSM P2988.20) distal femur
(RSM P2988.22) maxilla
(RSM P2988.23) proximal pedal phalanx
(RSM P2988.24) distal pedal phalanx
(RSM P2988.25) distal quadrate
(RSM P2988.26) proximal radius
(RSM P2989.1) incomplete femur (68.4 mm)
(RSM P2989.10) distal humerus
(RSM P2989.11) proximal humerus
(RSM P2989.12) proximal humerus
(RSM P2989.13) proximal humerus
(RSM P2989.14) proximal humerus
(RSM P2989.16) distal ulna
(RSM P2989.17) proximal ulna
(RSM P2989.18) proximal carpometacarpus
(RSM P2989.20) frontal
(RSM P2989.21) posterior mandible
(RSM P2989.22) dorsal vertebra (15.9 mm)
(RSM P2989.23) dorsal vertebra (15.5 mm)
(RSM P2989.24) ~third-fourth cervical vertebra (16.2 mm)
(RSM P2989.27) pedal phalanx (18.7 mm)
(RSM P2989.28) pedal phalanx (21.4 mm)
(RSM P2989.29) proximal pedal phalanx
(RSM P2989.30) proximal radius
(RSM P2989.34) distal carpometacarpus
(RSM P2989.35) proximal fibula
(RSM P2989.36) angular
(RSM P2989.38) frontal
(RSM P2989.41) incomplete pedal phalanx
(RSM P2989.193) splenial
(RSM P2989.194) splenial
(RSM P2995.1) humerus (102.8 mm)
(RSM P2995.4) frontal
(RSM P2995.5) partial maxilla
(RSM P2995.8) (juvenile?) proximal pedal phalanx
(RSM P2995.9) proximal fibula
(RSM P2997.2) femur (65.1 mm)
(RSM P2997.3) incomplete femur (66.0 mm)
(RSM P2997.5) distal femur
(RSM P2997.6) femur (60.2 mm)
(RSM P2997.7) incomplete femur (57.6 mm)
(RSM P2997.8) incomplete femur
(RSM P2997.11) incomplete femur
(RSM P2997.13) femur
(RSM P2997.21) proximal tarsometatarsus
(RSM P2997.23) distal tarsometatarsus
(RSM P2997.24) distal humerus
(RSM P2997.25) distal humerus
(RSM P2997.30) distal ulna
(RSM P2997.31) proximal coracoid
(RSM P2997.32) proximal carpometacarpus
(RSM P2997.33) proximal carpometacarpus
(RSM P2997.34) proximal carpometacarpus
(RSM P2997.35) surangular, articular
(RSM P2997.38) frontal
(RSM P2997.43) proximal tibiotarsus
(RSM P2997.44) proximal tibiotarsus
(RSM P2997.45) partial tibiotarsus
(RSM P2997.50) ~third-sixth dorsal vertebra (17.0 mm)
(RSM P2997.51) dorsal vertebra (17.4 mm)
(RSM P2997.52) cervical vertebra
(RSM P2997.53) cervical vertebra
(RSM P2997.54) ~tenth-thirteenth cervical vertebra (17.3 mm)
(RSM P2997.55) ~fourth-sixth cervical vertebra
(RSM P2997.56) anterior synsacrum
(RSM P2997.58) scapula (47.0 mm)
(RSM P2997.59) proximal scapula
(RSM P2997.60) proximal scapula
(RSM P2997.64) pelvic fragment
(RSM P2997.65) pedal phalanx III-2 (24.1 mm)
(RSM P2997.66) pedal phalanx III-2 (24.4 mm)
(RSM P2997.67) pedal phalanx II-1 (22.8 mm)
(RSM P2997.68) pedal phalanx II or IV-1 (24.8 mm)
(RSM P2997.70) proximal pedal phalanx
(RSM P2997.71) proximal pedal phalanx (36 mm)
(RSM P2997.72) (juvenile?) pedal phalanx II-1
(RSM P2997.73) pedal phalanx II-1
(RSM P2997.77) proximal femur
(RSM P2997.78) distal carpometacarpus
(RSM P2997.80) proximal fibula
(RSM P2997.82) proximal scapula
(RSM P2997.84) caudal vertebra
(RSM P2997.85) incomplete frontal
(RSM P3015.4) proximal tarsometatarsus
(RSM P3015.5) distal ulna
(RSM P3015.6) ~fourth-sixth cervical vertebra
(RSM P3015.7) ~third-fourth cervical vertebra (14.3 mm)
(RSM P3015.8) proximal scapula
(RSM P3015.9) pedal phalanx III or IV-1 (31.8 mm)
(RSM P3015.11) proximal carpometacarpus
(RSM P3015.12) partial femur
(RSM P3015.15) distal pedal phalanx
(RSM P3015.16) proximal scapula
(RSM P3015.17) proximal scapula
(RSM P3015.19) incomplete tarsometatarsus
(RSM P3015.20) partial cervical vertebra
Diagnosis- (after Tokaryk et al., 1997) larger than P. hardiei.
Other diagnoses- Tokaryk et al. (1997) also state the "distal rim"
of the femoral head is slanted toward the shaft, but the meaning of this is
uncertain. The medial tarsometatarsal cotyle is said to be level in medial view,
which is unlike Hesperornis and Parahesperornis, but similar to
Gansus and Enaliornis? seeleyi, so may be plesiomorphic. The neck
of trochlea III being lower anteriorly than that of trochlea IV is present in
Enaliornis? sedgwicki, Parahesperornis and Hesperornis
as well.
Comments- Excavated in 1992 and 1993, this was first noted as a new species of baptornithid by Cumbaa
and Tokaryk (1993) before being described by Tokaryk et al. (1997). As noted
in the Pasquiaornis comments, tankei may not belong to that genus
and may be more closely related to Baptornis and hesperornithids.
Tokaryk et al. (1997) reported that in 1994 and 1995 numerous
bird fossils similar to Pasquiaornis were discovered at the Bainbridge
River Bonebed. Cumbaa et al. (2006) states hundreds of bird specimens are known,
mostly hesperornithine, and illustrates four teeth. Sanchez et al. (2009) note
both P. hardiei and P? tankei
are represented in this material, which was described by Sanchez
(2010). Type B teeth of Sanchez (2010) are here assigned to P. tankei because they are smaller.
Cumbaa and Tokaryk mentioned two ichthyornithids from
the Carrot River beds of the Ashville Formation of Saskatchewan, which were later described by Tokaryk
et al. (1997) as Ichthyornis species A (RSM P2077.11, P2077.67, P2077.112
and P2487.5), Ichthyornis species B (RSM P2077.111) and I. sp.
indet. (RSM P2077.71). They referred the specimens to Ichthyornis based
on the coracoid scapular facet being nearly parallel to the sternal end of the
glenoid facet, which Clarke (2004) noted was found in Ichthyornis, but
not apomorphic. Tokaryk et al. distinguished species A from species B by its
gracility and round (vs. angular) scapular facet. Longrich (2009) suggested
the Ashville coracoids did not resemble Ichthyornis, and were referrable
to Pasquiaornis based on their dimorphism (P. hardiei vs. P?
tankei), pachyostosis, and supposed lack of coracoids in the Pasquiaornis
material. Sanchez (2010) confirms the coracoids are Pasquiaornis, and Ichthyornis species B is here placed in P? tankei.
References- Cumbaa and Tokaryk, 1993. Early birds, crocodile tears, and
fish tales: Cenomanian and Turonian marine vertebrates from Saskatchewan, Canada.
Journal of Vertebrate Paleontology. 13(3), 31A-32A.
Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds from Saskatchewan,
Canada: the oldest diverse avifauna known from North America. Journal of Vertebrate
Paleontology. 17(1), 172-176.
Clarke, 2002. The morphology and systematic position of Ichthyornis Marsh
and the phylogenetic relationships of basal Ornithurae. Ph.D. dissertation,
Yale University, New Haven, CT. 532 pp.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Cumbaa, Schr�der-Adams, Day and Phillips, 2006. Cenomanian bonebed faunas
from the northeastern margin, Western Interior Seaway. In Lucas and Sullivan
(eds). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum
of Natural History and Science Bulletin. 35, 139-155.
Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group
(Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30(1),
161-177.
Sanchez, Cumbaa and Schroder-Adams, 2009. Late Cretaceous (Cenomanian) Hesperornithiformes
from the Pasquia Hills, Saskatchewan, Canada. Journal of Vertebrate Paleontology.
29(3), 175A.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Tanaka, Takasaki and Tokaryk, 2021. Osteological histology of the Cretaceous seabird Pasquiaornis
(Avialae, Hesperornithiformes): Implications for the flight ability of
the basal hesperornithiforms. 2021 Northeast Natural History Conference
Poster Abstracts. 51.
P. sp. nov. (Sanchez, 2010)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Material- (RSM P2989.5) distal tarsometatarsus
(RSM P2989.7) incomplete tarsometatarsus (56.9 mm)
(RSM P2997.17) proximal tarsometatarsus
Comments- Sanchez et al. (2009) noted "the fauna from the Pasquia Hills bonebed includes a possible new species of Pasquiaornis." This material is referred to Pasquiaornis sp. A by Sanchez (2010).
References-
Sanchez, Cumbaa and Schroder-Adams, 2009. Late Cretaceous (Cenomanian) Hesperornithiformes
from the Pasquia Hills, Saskatchewan, Canada. Journal of Vertebrate Paleontology.
29(3), 175A.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
P. spp. (Sanchez, 2010)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Material-
?(RSM P2831.14) pedal ungual
(RSM P2831.29) tooth
(RSM P2831.45) tooth
(RSM P2831.48) tooth
(RSM P2831.49) tooth
(RSM P2831.50) tooth
(RSM P2831.51) tooth
(RSM P2989.189) tooth
(RSM P2989.190) tooth
(RSM P2989.191) tooth
(RSM P2989.192) tooth
(RSM coll.) over sixty teeth
Comments- This material is referred to Pasquiaornis by Sanchez (2010), but not to a particular species.
References- Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Chupkaornis Tanaka, Kobayashi, Kurihara, Fiorillo and Kano, 2017 online
C. keraorum Tanaka, Kobayashi, Kurihara, Fiorillo and Kano, 2017 online
Coniacian-Santonian, Late Cretaceous
Kashima Formation of the Yezo Group, Japan
Holotype-
(MCM.A.773) incomplete ~thirteenth cervical vertebra, partial
fourteenth cervical vertebra, incomplete sixteenth cervical neural
arch, incomplete seventeenth cervical vertebra, incomplete third dorsal
vertebra, incomplete fourth dorsal vertebra (20.00 mm), distal femora,
partial fibula
Diagnosis- (after Tanaka et
al., 2018) slender base of hypapophysis on fourth dorsal vertebra
(unknown in other non-hesperornithid hesperornithines); finger-like
projected tibiofibular crest of femur.
Other diagnoses- Tanaka et al.
(2018) list an emarginated lateral fossa on dorsal centra with
pronounced and sharply defined ventral edge, but this is plesiomorphic
being found in Pasquiaornis
and most earlier euornithines. The laterally expanded fibular
condyle of femur is stated to be present in all
hesperornithiforms. The completely heterocoelous articular
surface in dorsal vertebrae 3-4 at least (as defined by the authors) is
a synapomorphy shared with hesperornithoids.
Comments- Discovered in 1996. Tanaka et al. (2014) found this specimen to be more derived
than Enaliornis and Pasquiaornis,
but outside Hesperornithoidea. The same was true in Tanaka et al.
(2018), based on a reduced version of Bell and Chiappe's
hesperornithione analysis.
References- Tanaka, Kobayashi, Kano and Kurihara, 2012. The first record
of a hesperornithiform from Japan. Journal of Vertebrate Paleontology. Program
and Abstracts 2012, 183.
Tanaka, Kobayashi, Kurihara, Kano and Fiorillo, 2014. Phylogenetic position
of a new hesperornithiform from the Upper Cretaceous of Hokkaido, Japan. Journal
of Vertebrate Paleontology. Program and Abstracts 2014, 239.
Tanaka, Kobayashi, Kurihara, Fiorillo and Kano, 2018 (online 2017). The
oldest Asian hesperornithiform from the Upper Cretaceous of Japan, and
the phylogenetic reassessment of Hesperornithiformes. Journal of
Systematic Palaeontology. 16(8), 689-709.
Hesperornithoidea Marsh, 1872 vide Shufeldt,
1903
Definition- (Baptornis advenus + Hesperornis regalis)
(Martyniuk, 2012)
Diagnosis- (proposed) quadratojugal buttress on quadrate (absent in Hesperornis
regalis; unknown in more basal hesperornithines); articular surfaces of
dorsal vertebrae broad and trapezoidal; pygostyle less than two caudal vertebrae
in length (unknown in more basal hesperornithines); medial area of coracoid
depressed where supracoracoid foramen is (also in Apsaravis; unknown
in more basal hesperornithines); sternum lacks keel (unknown in more basal hesperornithines);
deltopectoral crest reduced in height (also in Patagopteryx and Aves;
unknown in more basal hesperornithines); bicipital crest lacks fossae (also
in Songlingornithidae and Patagopteryx; unknown in more basal hesperornithines);
brachial fossa on humerus poorly developed (also in Apsaravis); humerus
reduced to have indistinct distal condyles; femur very robust; tarsometatarsus
less than five times longer than broad; intercotylar prominence well developed
(also in Ichthyornis and Aves).
Comments- Shufeldt (1903) named Hesperornithoidea to contain both Enaliornithidae
and Hesperornithidae. A clade to the exclusion of Enaliornis was proposed
by Martin (1984) based on heterocoelous dorsal centra, but the amphicoelous
presacrals referred to Enaliornis are now thought to belong to another
taxon (Galton and Martin, 2002b). Bell and Chiappe (2016) recovered this clade
to the exclusion of Enaliornis and Pasquiaornis in their phylogenetic
analysis but left it unnamed.
References- Shufeldt, 1903. On the classification of certain groups of
birds. The American Naturalist. 37, 33-64.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Galton and Martin, 2002b. Postcranial anatomy and systematics of Enaliornis
Seeley, 1876, a footpropelled diving bird (Aves: Ornithurae: Hesperornithiformes)
from the Early Cretaceous of England. Revue de Paleobiologie. 21(2), 489-538.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Hesperornis? macdonaldi Martin
and Lim, 2002
Middle Campanian, Late Cretaceous
Sharon Springs Member of the Pierre Shale Group, South Dakota, US
Holotype- (LACM 9728) femur (44.7 mm)
Referred- (LACM 9727) femur (Bell and Chiappe, 2020)
Early Campanian, Late Cretaceous
Gammon Ferruginous Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.2012.01.13) femur (44.4 mm) (Aotsuka and Sato, 2016)
(CFDC B.2012.02.13) femur (52.5 mm) (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.80.08.16) femur (49.4 mm) (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Millwood Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.81.03.16) femur (48.2 mm) (Aotsuka and Sato, 2016)
(CFDC B.2006.01.05) femur (Aotsuka and Sato, 2016)
Diagnosis- (after Martin and Lim, 2002) small size, with tarsometatarsal
length estimated at <60 mm (also in Pasquiaornis hardiei).
Other diagnoses- Martin and Lim (2002) also diagnosed this species based
on the deeply concave lateral femoral margin, which is also present in Hesperornis
regalis.
Comments- Bryant first mentions the holotype as one of "several
femora including some very small (and presumably very young) ones collected
by myself and others working with a Los Angeles County Museum field party in
1964", though it was undescribed at the time. Martin and Lim (2002) believe
the holotype is an adult due to its well formed articular surfaces, but Bell
and Chiappe (2016) stated the small size "may be due to the immature ages
of the specimen, which is difficult to determine due to the poor preservation
of the elements and in the absence of histological data." Aotsuka and Sato
(2016) referred femora to macdonaldi from Manitoba based on their size.
This species was described in Hesperornis by Martin and Lim. However
it has an uncertain placement, as the femora of hesperornithids besides Brodavis?
varneri and Hesperornis regalis are still undescribed, and mostly
unpreserved. The extreme robusticity is shared with H. regalis, but seemingly
not H. bazhanovi or Parahesperornis. The strong anteroposterior
compression of the shaft is also shared with H. regalis but not B?
varneri or H. crassipes. However, the medial condyle is not distally
projected, unlike B? varneri and H. regalis. The small size is
unlike Hesperornithidae. Bell and Chiappe found macdonaldi to code identically
to taxa placed in Hesperornis here.
References- Bryant, 1983. Hesperornis in Alaska. Paleobios. 40,
1-8.
Martin
and Lim, 2002. New information on the hesperornithiform radiation. In
Zhou and Zhang (eds.). Proceedings of the 5th Symposium of the Society
of Avian Paleontology and Evolution. 165-174.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
Judinornis Nessov and
Borkin, 1983
J. nogontsavensis Nessov and Borkin, 1983
Late Campanian-Early Maastrichtian, Late Cretaceous
Nogon Tsav, Nemegt Formation, Mongolia
Holotype- (ZIN PO 3389) incomplete last dorsal vertebra (14.1 mm)
Diagnosis- (proposed) highly elongate dorsal vertebrae (~2.5 longer than
posteriorly high).
Other diagnoses- Kurochkin (2000) listed dorsal central articular surfaces
transversely expanded, ventral surface of dorsal centrum transversely narrow
in middle and expanded posteriorly, and prezygapophyses with little transverse
separation in his diagnosis, but then correctly noted these are general hesperornithine
characters in the comments section. In addition, he listed the trapezoidal dorsal
central articular surfaces in his diagnosis, but these are found in other hesperornithines
as well.
Comments- Nessov and Borkin (1983) originally referred Judinornis
to the Charadriiformes, but it was reassigned to the Baptornithidae without
evidence by Nessov (1986). Kurochkin (2001) listed characters shared with Baptornis,
but these are plesiomorphic as noted in the Baptornithidae comments. The holotype
is indeed extremely similar to Baptornis, though no synapomorphies seem
evident. The low central articular surfaces with projecting ventrolateral corners
indicate it is more derived than Enaliornis. Several characters are more
similar to Baptornis and Parascaniornis than to Hesperornis-
the prezygapophysis is elongate and well separated from the centrum in lateral
view; ventral centrum surface is transversely constricted; the transverse processes
extend further anteriorly.
References- Nessov and Borkin, 1983. [New records of bird bones from
Cretaceous of Mongolia and Middle Asia] Trudy Zoologicheskogo Instituta Akademii
Nauk SSSR. 116, 108-110.
Nessov, 1986. The first record of the Late Cretaceous bird Ichthyornis
in the Old World and some other bird bones from the Cretaceous and Paleogene
of Soviet Middle Asia. Proc. Zool. Inst. USSR Acad. Sci.. 147, 31-38.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. In Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Parascaniornis Lambrecht,
1933
P. stensioei Lambrecht, 1933
Early Campanian, Late Cretaceous
Bellemnellocamax mamillatus zone, Ivo Klack, Sweden
Holotype- (MGUH 1908.214) posterior dorsal vertebra (15 mm)
Referred- ?(RM PZ R1261) distal tarsometatarsus (Rees and Lindgren, 2005)
Comments- The holotype was discovered in 1908 and described by Lambrecht
(1933) as a "scaniornithid" (Scaniornis is a Paleocene bird
variously allied with ciconiiforms or phoenicopteriforms). Lambrecht originally
spelled the species stensi�i, which must be corrected to stensioei
according to ICZN Article 32.5.2.1- "in a name published before 1985 and
based upon a German word, the umlaut sign is deleted from a vowel and the letter
"e" is to be inserted after that vowel." Howard (1950) believed
Parascaniornis was a phoenicopteriform, but it was reidentified as a
hesperornithine by Nessov (in Mourer-Chauvire, 1990) and Nessov and Prizemlin
(1991). Rees and Lindgren (2005) reexamined this vertebra and found it to be
identical to Baptornis advenus and RSM P2306.2 of the Judith River Group,
except for the more horizontally directed prezygapophyses. They viewed it as
indeterminate within Baptornis and called it Baptornis sp., but
as Ford (online, 1995) notes, you cannot sink a named species into "sp.".
Instead, it would be named Baptornis stensioei, though this combination
is not yet published. However, Rees and Lindgren did not list any derived characters
that could be used to place stensioei in Baptornis, nor even any
shared primitive characters. The low central articular surfaces with projecting
ventrolateral corners indicate it is more derived than Enaliornis. In
elongation, Parascansiornis is similar to Baptornis, more elongate
than Hesperornis, but less than Judinornis. The prezygapophysis
is elongate and well separated from the centrum in lateral view, as in Baptornis
and Judinornis, but unlike Hesperornis. The ventral surface is
transversely constricted and the transverse processes extend further anteriorly
as in Baptornis and especially Judinornis, but less than Hesperornis.
As Parascaniornis is roughly equally similar to Baptornis and
Judinornis, and shares to obvious apomorphies with either, it is here
retained in its own genus.
References- Lambrecht, 1933. Handbuch der Pal�ornithologie. Berlin,
Gebr�der Borntraeger. 1024 pp.
Howard, 1950. Fossil evidence of avian evolution. Ibis. 92, 1-21.
Mourer-Chauvire, 1990. Society of Avian Paleontology and Evolution Information
Newsletter. 4.
Nessov and Prizemlin, 1991. A large advanced flightless marine bird of the order
Hesperornithiformes of the Late Senonian of Turgai Strait - the first finding
of the group in the USSR. USSR Academy of Sciences, Proceedings of the Zoological
Institute. 239, 85-107. [In Russian].
Nessov, 1992. [Flightless birds of meridional Late Cretaceous sea straits of
North America, Scandinavia, Russia and Kazakhstan as indicators of features
of oceanic circulation.] Byulleten Moskovskogo Obshchestva Ispytatelet Prirody
Otdel Geologicheskii. 67, 78-83.
Rees and Lindgren, 1999. Early Campanian hesperornithiform birds from the Kristianstad
Basin, southern Sweden. in Hoch and Brantsen (eds). Secondary adaptation to
life in water. Abstracts. University of Copenhagen, Copenhagen. 53.
Ford, online 2005. http://www.dinohunter.info/html/articles2005.htm
Rees and Lindgren, 2005. Aquatic birds from the Upper Cretaceous (Lower Campanian)
of Sweden and the biology and distribution of hesperornithiforms. Palaeontology.
48(6), 1321-1329.
undescribed hesperornithoid (Sanchez, Cumbaa and Schroder-Adams, 2009)
Middle Cenomanian, Late Cretaceous
Bainbridge River, Belle Fourche Member of the Ashville Formation, Saskatchewan, Canada
Material- (RSM P2626.43) partial humerus (Sanchez, 2010)
(RSM P2986.1) humerus (74.0 mm) (Sanchez, 2010)
?(RSM P2997.26) dorsal rib or humerus (Sanchez, 2010)
(RSM P3015.13) distal humerus (Sanchez, 2010)
Comments- Sanchez et al. (2009) note that among the 250 bird bones from the Bainbridge
River Bonebed (most of which are Pasquiaornis), some are from a "possible
new hesperornithiform genus." Sanchez's (2010) thesis reveal these to consist of humeri more reduced than Pasquiaornis. His appendix one lists RSM P2997.26 as "reduced wing or rib."
References- Sanchez, Cumbaa and Schroder-Adams, 2009. Late Cretaceous
(Cenomanian) Hesperornithiformes from the Pasquia Hills, Saskatchewan, Canada.
Journal of Vertebrate Paleontology. 29(3), 175A.
Sanchez, 2010. Late Cretaceous (Cenomanian) Hesperornithiformes from
the Pasquia Hills, Saskatchewan, Canada. Masters thesis, Carleton
University. 238 pp.
Hesperornithoidea indet. (Tokaryk and Harington, 1992)
Late Campanian, Late Cretaceous
Judith River Group, Saskatchewan, Canada
Material- (RSM P2306.2) fourth dorsal vertebra (21.2 mm)
Comments- This specimen was discovered in 1975-1976 and was described
as Baptornis sp. by Tokaryk and Harington (1992). Of the characters used
to refer this to Baptornis, the heterocoely of dorsal four is present
in all hesperornithines. The narrower and lower posterior central articular
surface (compared to centrum length) is plesiomorphic, being present in Enaliornis
and Judinornis as well, while the lower anterior central articular surface
and small parapophysis are also present in Judinornis. The centrally
placed hypapophysis is also present in Hesperornis. However, as the centrum
is trapezoidal, it is probably more derived than Enaliornis.
Reference- Tokaryk and Harington, 1992. Baptornis sp. (Aves: Hesperornithiformes)
from the Judith River Formation (Campanian) of Saskatchewan, Canada. Journal
of Paleontology. 66(6), 1010-1012.
Hesperornithoidea indet. (Aotsuka and Sato, 2016)
Early Campanian, Late Cretaceous
Gammon Ferruginous Member of the Pierre Shale Group, Manitoba, Canada
Material- (CFDC B.2010.03.13) vertebra (Aotsuka and Sato, 2016)
(CFDC B.2010.05.03) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.2011.01.13) vertebra (Aotsuka and Sato, 2016)
(CFDC B.2011.04.13) vertebra (Aotsuka and Sato, 2016)
(CFDC B.2011.06.13) vertebra (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.00.33.03) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.38.00) fibula (Aotsuka and Sato, 2016)
(CFDC B.00.39.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.41.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.44.00) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.00.45.00) vertebra (Aotsuka and Sato, 2016)
(CFDC B.00.48.00) vertebra (Aotsuka and Sato, 2016)
(CFDC B.00.49.00) vertebra (Aotsuka and Sato, 2016)
(CFDC B.00.50.00; lost) vertebra (Aotsuka and Sato, 2016)
(CFDC B.00.52.00) vertebra (Aotsuka and Sato, 2016)
(CFDC B.00.53.00) vertebra (Aotsuka and Sato, 2016)
(CFDC B.04.01.15) vertebra (Aotsuka and Sato, 2016)
(CFDC B.04.01.23) three vertebrae (Aotsuka and Sato, 2016)
(CFDC B.04.02.23) vertebra (Aotsuka and Sato, 2016)
(CFDC B.06.01.03) three dorsal vertebrae (Aotsuka and Sato, 2016)
(CFDC B.06.01.15) vertebra (Aotsuka and Sato, 2016)
(CFDC B.06.02.03) vertebra (Aotsuka and Sato, 2016)
(CFDC B.08.01-2.15) vertebra (Aotsuka and Sato, 2016)
(CFDC B.08.01.22) four vertebrae (Aotsuka and Sato, 2016)
(CFDC B.08.03.23) vertebra (Aotsuka and Sato, 2016)
(CFDC B.76.02.06) vertebra (Aotsuka and Sato, 2016)
(CFDC B.77.00.07) three vertebrae (Aotsuka and Sato, 2016)
(CFDC B.77.01.07) vertebra, pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.78.03.07) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.79.01.12) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.79.04.13) vertebra (Aotsuka and Sato, 2016)
(CFDC B.79.06.13) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.79.07.13) tibiotarsus, fibula (Aotsuka and Sato, 2016)
(CFDC B.80.02.15) fibula, pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.81.05.16) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.81.06.16) vertebra (Aotsuka and Sato, 2016)
(CFDC B.81.09.16) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.82.02.05) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.82.07.17; lost) vertebra (Aotsuka and Sato, 2016)
(CFDC B.82.08-2.17) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.82.12.17) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.82.13.17) two pedal phalanges (Aotsuka and Sato, 2016)
(CFDC B.82.14.17) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.82.16.17; lost) vertebra (Aotsuka and Sato, 2016)
(CFDC B.83.05.18) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.84.01.17) vertebra (Aotsuka and Sato, 2016)
(CFDC B.84.02.03) vertebra, tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.85.02.03) vertebra (Aotsuka and Sato, 2016)
(CFDC B.85.02.05) vertebra (Aotsuka and Sato, 2016)
(FMNH PA287) pedal phalanx (Aotsuka and Sato, 2016)
(ROM coll; lost) seven vertebrae (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Millwood Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.04.02.15) tbiotarsus (Aotsuka and Sato, 2016)
(CFDC B.05.02.15) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.05.02.23) patella, pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.05.04.15) vertebra, pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.06.01-2.05) seven vertebrae, pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.06.02.15) three vertebrae (Aotsuka and Sato, 2016)
(CFDC B.06.02.23) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.06.03.23) vertebra (Aotsuka and Sato, 2016)
(CFDC B.07.01.23) dorsal vertebra (Aotsuka and Sato, 2016)
(CFDC B.07.05.23) vertebra (Aotsuka and Sato, 2016)
(CFDC B.08.01.23) dorsal vertebra (Aotsuka and Sato, 2016)
(CFDC B.08.02.23) vertebra (Aotsuka and Sato, 2016)
(CFDC B.08.04.23) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.2010.02.15) pedal phalanx (Aotsuka and Sato, 2016)
(CFDC B.2010.02.23) two pedal phalanges (Aotsuka and Sato, 2016)
Comments- Aotsuka and Sato (2016) state tibiotarsi CFDC.B.00.33.00, B.06.02.23,
B.78.03.07, B.79.07.13, B.81.05.16 and B.81.09.16 resemble Baptornis
in size and gracility, while the vertebrae CFDC.B.05.02.15 [typo, as that specimen
is listed as a tibiotarsus], B.06.01.03, B.07.01.23, and B.08.01.23 also resemble
Baptornis in size. They note that these elements are unknown in small
Hesperornis species however. At least some of the phalanges are said
to resemble Hesperornis more than Baptornis in size and crescent-peg
articulations, the latter of which are also known in Parahesperornis
but unpreserved in Brodavis and Fumicollis (these would thus be
hesperornithids but are not assigned to the family here because exactly which
phalanges have the character is unreported).
Reference-
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
Baptornithidae American Ornithologist Union,
1910
Definition- (Baptornis advenus ~ Hesperornis regalis) (Martyniuk,
2012)
Other diagnoses- Martin and Tate (1976) included several characters in
their diagnosis for Baptornithidae, in which they included Baptornis
and Neogaeornis (now thought to be a gaviiform). The character "fully
heterocoelous vertebrae" was supposed to distinguish them from Enaliornis,
but the amphicoelous presacral vertebrae assigned to that taxon are now thought
to belong to another bird. The angled uncinate processes and elongate pygostyle
are unknown for any putative baptornithid except B. advenus, so are made
an apomorphy of that species here. The highly compressed pygostyle and uncompressed
patella of Baptornis advenus are unlike Hesperornis, but unknown
in other basal euornithines, so are provisionally made apomorphies of that
species. The unfused chevrons ("intercentral bones"), slender coracoid,
elongate preacetabular process, metatarsal II trochlea which is less rotated
ventromedially, open groove between metatarsal trochlea III and IV, and comparatively
small metatarsal trochlea IV are primitive characters.
Tokaryk et al. (1997) use some of the previous characters and the slender femora
to place Pasquiaornis in the Baptornithidae, but this is also primitive.
Kurochkin (2000) noted three characters he thought united Baptornis with
Judinornis in the Baptornithidae. Of these, a pneumatic pit between the
transverse process and prezygapophysis on dorsal vertebrae is probably plesiomorphic,
being present in Ichthyornis as well. A ventrally flat centrum is only
found in the last dorsal of Baptornis advenus, as more anterior vertebrae
are similar to Hesperornis in having prominent hyapophyses. Yet the last
dorsal of Enaliornis also lacks hyapophyses, as do the last few dorsals
of Ichthyornis and Gansus, so this is a plesiomorphy. Some presacrals
of Baptornis advenus and Brodavis? varneri resemble Judinornis
in having a central pit on their articular surfaces. While these seem to be
absent in the two preserved presacrals of Enaliornis, they are likely
to be remnants of the amphicoelous condition in more basal euornithines like
Ichthyornis, Gansus and Yixianornis.
Martin and Cordes-Person (2007) note other characters supposedly diagnostic
of baptornithids. A smooth femoral patellar groove, subcircular femoral shaft,
and unreduced metatarsal II trochlea are plesiomorphic. The cervical vertebrae
of Brodavis? varneri are said to be like those of B. advenus in
being more elongate than Hesperornis (and Parahesperornis), but
this does not seem to be true based on the photograph.
Everhart and Bell (2009) diagnosed a Baptornithidae including Baptornis,
Pasquiaornis and FHSM VP-6318. The rounded intercotylar prominence is
a plesiomorphy compared to Hesperornis, while the intermediate height
between Enaliornis and Hesperornis cannot be used as a synapomorphy
to exclude both of those taxa from a baptornithid clade. Similarly, the indentations
which partially constrict the distal vascular foramen between metatarsals III
and IV are an intermediate state between the unconstricted Enaliornis
and the distally closed foramen in Hesperornis, and are also seen in
Parahesperornis. The infracotylar fossa and anteriorly tilted cotyla
are present in hesperornithids as well. Contra Everhart and Bell, Enaliornis
barretti and E? seeleyi also have the groove on trochlea III deeper
than that on trochlea IV.
Comments- Baptornithidae has been a paraphyletic taxon for hesperornithines
which are more basal than Parahesperornis, but there is currently no
evidence any other species was more closely related to Baptornis than
to Hesperornis. Taxa which have been assigned to Baptornithidae in the
past include Eupterornis (Romer, 1933), Neogaeornis (Brodkorb,
1963), Judinornis (Nessov, 1986) and Pasquiaornis (Tokaryk et
al., 1997). The former two are now thought to be gaviiforms (Brodkorb, 1963
and Olson, 1992 respectively), while the latter two are Baptornis-grade
hesperornithines.
References- American Ornithologist Union, 1910. Checklist of North American
birds. Third edition. American Ornithologist’s Union, New York. 430 pp.
Romer, 1933. Vertebrate Paleontology. University of Chicago Press, Chicago.
Brodkorb, 1963. Catalogue of fossil birds. Part 1 (Archaeopterygiformes through
Ardeiformes). Bull. Florida State Mus., Bioi. Sci.. 7, 179-293.
Martin and Tate, 1976. The skeleton of Baptornis advenus (Aves:
Hesperornithiformes). In Olson (ed.). Collected Papers in Avian
Phylogeny Honoring the 90th Birthday of Alaxander Wetmore. Smithsonian
Contributions to Paleobiology. 27, 35-66.
Nessov, 1986. The first record of the Late Cretaceous bird Ichthyornis
in the Old World and some other bird bones from the Cretaceous and Paleogene
of Soviet Middle Asia. Proc. Zool. Inst. USSR Acad. Sci.. 147, 31-38.
Olson, 1992. Neogaeornis wetzeli Lambrecht, a Cretaceous loon from Chile
(Aves: Gaviidae). Journal of Vertebrate Paleontology. 12, 122-124.
Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds from Saskatchewan,
Canada: the oldest diverse avifauna known from North America. Journal of Vertebrate
Paleontology. 17(1), 172-176.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Martin and Cordes-Person, 2007. A new species of the diving bird Baptornis
(Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous)
of southwestern South Dakota. The Geological Society of America, Special Paper.
427, 227-237.
Everhart and Bell, 2009. A hesperornithiform limb bone from the basal Greenhorn
Formation (Late Cretaceous; Middle Cenomanian) of north central Kansas. Journal
of Vertebrate Paleontology. 29(3), 952-956.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Baptornis Marsh, 1877
Diagnosis- as for B. advenus.
Other diagnoses- Martin and Tate (1976) used the size as a diagnostic
character of Baptornis, but it is similar to Pasquiaornis tankei.
The greatly reduced forelimb is present in hesperornithids as well, while the
retention of the radius and ulna are plesiomorphies also present in Pasquiaornis.
Martin and Tate also distinguished Baptornis from Neogaeornis
by having a less compressed tarsometatarsus, but this is true of all hesperornithines.
Tokaryk and Harington (1992) include a few dorsal characters in their diagnosis.
The heterocoely of dorsal four is present in all hesperornithines. The narrower
and lower posterior central articular surface (compared to centrum length) is
plesiomorphic, being present in Enaliornis and Judinornis as well,
while the lower anterior central articular surface and small parapophysis are
also present in Judinornis. The centrally placed hypapophysis is also
present in Hesperornis.
Martin and Cordes-Person (2007) list several synapomorphies of Baptornis
advenus and "B." varneri. As noted under Baptornithidae,
the cervical vertebrae of varneri do not appear to be more elongate than
those of Hesperornis, contra the text. The absence of "vertebrarterial
canals" (= transverse foramina) in Baptornis seems implausible,
as all theropods have diapophyseal and parapophyseal articulations with their
cervical ribs, and may refer to an absence of fused cervical ribs instead. This
is affected by ontogeny, and was not stated to be certainly absent in B.
advenus by Martin and Tate in any case. Heterocoelous dorsal vertebrae and
medial femoral condyles which are smaller than the lateral condyle are present
in all hesperornithines. Pits in the posterior central articular surfaces of
presacral centra, a subcircular femoral cross section, a smooth patellar groove
and subequally sized tarsometatarsal trochlea are primitive characters.
Comments- Several other taxa have been referred to Baptornis in
the past. Kurochkin (1988) referred a distal tibiotarsus from the Nemegt Formation
of Mongolia to Baptornis sp., but this is here shown to resemble Enaliornis?
seeleyi as well and thus referred to Hesperornithes incertae sedis. Tokaryk
and Harington (1992) described a dorsal vertebra from the Judith River Group
of Asakatchewan as Baptornis sp., but the characters they used were symplesiomorphic
and the specimen is here referred to the Baptornis + Hesperornis
clade as a nomen dubium. Nessov (1997) thought some small hesperornithine material
from the Zhuralovskaya Svita of Kazakhstan could be referrable to Baptornis,
but this undescribed material is here referred to Hesperornithes incertae sedis.
Rees and Lindgren (2005) placed Parascaniornis stensioei in Baptornis
as B. sp., which as noted in its description here was not based on any
synapomorphies. More recently, a specimen was described as the new species Baptornis
varneri by Martin and Cordes-Person (2007), but this is based on a mix of
symplesiomorphies and synapomorphies of more inclusive clades as noted above.
The species is here placed as a basal hesperornithid and has been provisionally
reassigned to Brodavis. A distal femur from the Pierre Shale group of
Manitoba was initially identified as Baptornis advenus by Aotsuka et
al. (2012), but Aotsuka and Sato (2016) later described it as Brodavis sp..
References- Marsh, 1877. Characters of the Odontornithes, with notice
of a new allied genus. American Journal of Science. 14, 85-87.
Martin and Tate, 1976. The skeleton of Baptornis advenus (Aves: Hesperornithiformes).
in Olson (ed). Collected papers in avian phylogeny honoring the 90th birthday
of Alaxander Wetmore. Smithsonian Contributions to Paleobiology. 27, 35-66.
Kurochkin, 1988. [Cretaceous birds of Mongolia and their significance for study
of the phylogeny of class Aves.] Trudy Sovmestnoi Sovetsko-Mongolskoi Paleontologicheskoi
Ekspeditsii. 34, 33-42.
Tokaryk and Harington, 1992. Baptornis sp. (Aves: Hesperornithiformes)
from the Judith River Formation (Campanian) of Saskatchewan, Canada. Journal
of Paleontology. 66(6), 1010-1012.
Nessov, 1997. Cretaceous non-marine vertebrates of Northern Eurasia. St. Petersburg
State University, St-Petersburg. 218 pp.
Rees and Lindgren, 2005. Aquatic birds from the Upper Cretaceous (Lower Campanian)
of Sweden and the biology and distribution of hesperornithiforms. Palaeontology.
48(6), 1321-1329.
Martin and Cordes-Person, 2007. A new species of the diving bird Baptornis
(Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous)
of southwestern South Dakota. The Geological Society of America, Special Paper.
427, 227-237.
Aotsuka, Hatcher, Janzic and Sato, 2012. Diversity of the Hesperornithiformes
(Aves) from the Upper Cretaceous Pierre Shale in Southern Manitoba, Canada.
Journal of Vertebrate Paleontology. Program and Abstracts 2012, 57.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
B. advenus Marsh, 1877
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Lectotype- (YPM 1465) distal tarsometatarsus
Paralectotype- ?(YPM 5768; = YPM 1465 in part) (juvenile) proximal tarsometatarsus
Referred- (AMNH 5101) premaxillary fragment, frontal fragment (lost), ventral
quadrate (lost), atlantal intercentrum, axis, fourteen cervical vertebrae, six
dorsal vertebrae, dorsal rib fragments, synsacrum, four proximal caudal vertebrae,
mid caudal vertebra, partial pelvis, distal tibiotarsus, tarsometatarsi (89.9 mm), partial phalanx (Martin and Tate, 1976)
(FMNH 395) posterior mandible, sixth dorsal vertebra (18.7 mm), dorsal rib fragments,
synsacrum, five mid caudal vertebrae, pygostyle, pelvic fragments, femora (72
mm), tibiotarsi (194.76 mm), fibula, metatarsal I (14 mm), phalanx I-1 (22 mm),
tarsometatarsus (83 mm), phalanx II-2 (31.7 mm), phalanx III-1 (23.73 mm), phalanx III-3 (20.5 mm), phalanx
IV-1 (36.55 mm), phalanx IV-2 (25 mm), phalanx IV-3 (23 mm), phalanx IV-4 (23 mm),
six pedal phalanges, two pedal unguals (Martin and Tate, 1976)
?(Fick Fossil Museum coll.) premaxillary fragment(?), femur, proximal tibiotarsus,
tibiotarsal shaft, distal tibiotarsus, proximal fibula, two tarsometatarsi,
three incomplete tarsometatarsi, eleven fragments (Martin and Tate, 1976)
(KUVP 2290) six cervical vertebrae, three dorsal vertebrae, dorsal rib fragments,
partial synsacrum, proximal scapula, incomplete coracoid (52.93 mm), incomplete humerus
(~118 mm), radius (20.5 mm), ulna (21.6 mm), anterior ilium, femora (74.90 mm),
patella (20.51 mm), partial tibiotarsi, proximal fibulae, partial tarsometatarsus
(~83 mm) (Lucas, 1903)
(KUVP 16112) (juvenile) premaxilla (lost), eighth cervical vertebra,
thirteenth cervical vertebra, fourteenth cervical vertebra, three
partial cervical vertebrae, second dorsal vertebra (~20 mm), third
dorsal vertebra (21 mm), fourth dorsal vertebra (~22 mm), fifth dorsal
vertebra (22 mm), dorsal rib fragments, synsacral fragment, partial
pelvis, proximal femora, distal femur, tibial shaft, distal tibiae,
incomplete metatarsi, phalanx III-1 (29.5 mm), proximal phalanx, distal
phalanx (Walker, 1967)
?(YPM 1467) femur, tibiotarsus (~125 mm) (Marsh, 1880)
Diagnosis- (after Marsh, 1880) prominent medial tibial crest.
(after Lucas, 1903) cervical vertebrae highly elongate; procoracoid process
absent.
(proposed) uncinate processes angled dorsally at base; pygostyle longer than
four vertebrae; highly transversely compressed pygostyle; pubis and ischium
appressed; patella transversely wider than deep; proximolateral fossa for fibula
on tibiotarsus narrow and deep; intertrochlear grooves on tarsometatarsus not
extending proximal to trochlea II.
Other diagnoses- Marsh (1877) mentions only plesiomorphies- metatarsal
trochlea III and IV subequal in width and length.
Marsh (1880) later mentions the slender femur, which is also plesiomorphic.
Lucas (1903) lists several features which differ from Hesperornis, but
most are plesiomorphic- short sacrum; elongate coracoid; radius and ulna present;
femur not projected transversely; high cnemial crest.
The extreme transverse slenderness of the tarsometatarsus noted by Shufeldt
(1915) is also present in Pasquiaornis hardiei.
Martin and Cordes-Person (2007) listed several characters for B. advenus,
most of which are plesiomorphic and also present in Brodavis? varneri-
heterocoelous dorsal vertebrae; subcircular femoral cross section; smooth patellar
groove in femur; tarsometatarsus with proximal cap; metatarsal II trochlea which
is less rotated ventromedially. The lack of crescent and peg articulations on
pedal digit IV phalanges is also primitive, though unpreserved in B? varneri
and other non-hesperornithid hesperornithines. The femoral medial condyle is
actually larger than in B? varneri (as in Pasquiaornis), not smaller
as in Enaliornis and Hesperornis. The distal tibiotarsus being
angled anteriorly is plesiomorphic as well, being shared with Parahesperornis.
Comments- The lectotype and paralectotype were discovered in 1876 and
described by Marsh in 1877, though Shufeldt (1915) and Martin and Tate (1976)
confirmed they were from different individuals, as YPM 1465 is adult and YPM
5768 is juvenile. They designated YPM 1465 the lectotype. The large humerus
reported by Walker (1967) for KUVP 16112 is a tibial shaft. Elzanowski et al.
(2001) state that there is no quadrate catalogued under AMNH 5101, nor could
any record of it be found there. They furthermore believe that the quadrate
was too small to be derived from the specimen and question its referral to Baptornis,
though they do believe it is an "odontognath." Bell and Chiappe (2020)
stated "very small fragments of the quadrate and frontal of Baptornis
(AMNH 5101) were previously reported, however no such elements are
included with the specimen today. ... Likewise, a fragment of the bill
was reported with Baptornis
specimen KUVP 16112, however the specimen did not include material
identifiable as such when consulted for this study." Martin and
Tate (1976) noted they examined specimens at the Fick Fossil Museum,
which are not described further, but are photographed on Oceans of
Kansas (Everhart, online 2005). Chiappe (1996) listed KUVP 2295 as a Baptornis specimen, but probably meant KUVP 2290. Bell and
Chiappe (2016) found most referred specimens coded identically or near identically
to each other, but did not mention YPM 1467, YPM 5768 or the Fick Fossil Museum
specimen. UNSM 20030 was described by Martin and Tate (1976) as a specimen of
B. advenus, but Bell and Chiappe found it was actually a more derived
taxon sister to Parahesperornis+Hesperornis and described it later
(Bell and Chiappe, 2015) as Fumicollis hoffmani.
References- Marsh, 1877. Characters of the Odontornithes, with notice
of a new allied genus. American Journal of Science. 14, 85-87.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Lucas, 1903. Notes on the osteology and relationships of the fossil birds of
the genera Hesperornis, Hargeria, Baptornis, and Diatryma.
Proceedings of the United States National Museum. 26, 545-556.
Brown, 1911. Notes on the restorations of the Cretaceous birds Hesperornis
and Baptornis. Annals of the New York Academy of Sciences. 20, 401.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions
of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Walker, 1967. Revival of interest in the toothed birds of Kansas. Transactions
of the Kansas Academy of Sciences. 70(1), 60-66.
Martin and Tate, 1969. New information on Baptornis advenus. Proceedings
of the Nebraska Academy of Sciences (79th Annual Meeting). 49-50.
Martin and Tate, 1976. The skeleton of Baptornis advenus (Aves: Hesperornithiformes).
in Olson (ed). Collected papers in avian phylogeny honoring the 90th birthday
of Alaxander Wetmore. Smithsonian Contributions to Paleobiology. 27, 35-66.
Martin and Bonner, 1977. An immature specimen of Baptornis advenus from
the Cretaceous of Kansas. The Auk. 94, 787-789.
Witmer, 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological
Journal of the Linnaean Society of London. 100, 327-378.
Chiappe, 1996. Late Cretaceous birds of Southern South America: Anatomy and
systematics of Enantiornithes and Patagopteryx deferrariisi. In Arratia
(ed.). Contributions of Southern South America to Vertebrate Paleontology. M�nchner
Geowissenschaftliche Abhandlungen (A). 30, 203-244.
Elzanowski, Paul and Stidham, 2001. An avian quadrate from the Late Cretaceous
Lance Formation of Wyoming. Journal of Vertebrate Paleontology. 20(4), 712-719.
Everhart, online 2005. http://www.oceansofkansas.com/Birds/fickhesp.jpg
Martin and Cordes-Person, 2007. A new species of the diving bird Baptornis
(Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous)
of southwestern South Dakota. The Geological Society of America, Special Paper.
427, 227-237.
Everhart, online 2008-2017. http://www.oceansofkansas.com/Baptornis.html
Bell and Chiappe, 2015. Identification of a new hesperornithiform from the
Cretaceous Niobrara Chalk and implications for ecologic diversity among early
diving birds. PLoS ONE. 10(11), e0141690.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
unnamed baptornithid (Martin, 1983)
Middle Cenomanian, Late Cretaceous
Basal Lincoln Limestone Member of the Greenhorn Limestone, Kansas, US
Material- (FHSM VP-6318) proximal and distal tarsometatarsus (16.7 mm wide
proximally)
Comments- This was discovered in 1979 and mentioned by Martin (1983)
and Tokaryk et al. (1997). Though the description was listed on the Oceans of
Kansas website as set to appear in volume 28(4) of JVP (Everhart, online 2008), it was not published
until volume 29(3). Everhart and Bell (2009) refer this specimen to Baptornithidae
based on several problematic characters (see Baptornithidae other diagnoses).
Bell and Chiappe (2016) found it to code identically to Baptornis advenus
in their analysis.
References- Martin, 1983. The origin and early radiation of birds. in
Bush and Clark (eds.). Perspectives in Ornithology. Cambridge University Press,
Cambridge. 291-338.
Tokaryk, Cumbaa and Storer, 1997. Early Late Cretaceous birds from Saskatchewan,
Canada: the oldest diverse avifauna known from North America. Journal of Vertebrate
Paleontology. 17(1), 172-176.
Everhart, online 2008. https://web.archive.org/web/20081101143014/http://www.oceansofkansas.com/Hesperornis.html
Everhart and Bell, 2009. A hesperornithiform limb bone from the basal Greenhorn
Formation (Late Cretaceous; Middle Cenomanian) of north central Kansas. Journal
of Vertebrate Paleontology. 29(3), 952-956.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Hesperornithidae Marsh, 1876
= Hesperornidae Marsh, 1872
= Asiahesperornithinae Nessov and Prizemlin, 1991
Definition- (Hesperornis regalis <- Baptornis advenus)
(Clarke, 2004)
Other definitions- (Parahesperornis alexi + Hesperornis regalis) (Bell and Chiappe, 2020)
Diagnosis- (proposed) proximal tibiotarsal shaft gradually expanded anteroposteriorly;
elongate fibular crest on tibiotarsus (~59% of tibiotarsal length); large size
(tarsometatarsus >20 mm in proximal transverse width).
Comments- Marsh (1872) originally called this family Hesperornidae, but
this had to be corrected to Hesperornithidae as there is no genus 'Hesperorna'. Nessov and Prizemlin's (1991)
taxon Asiahesperornithinae is redundant as Asiahesperornis seems to be
nested within Hesperornis itself.
References- Marsh, 1872. Preliminary description of Hesperornis regalis,
with notices of four other new species of Cretaceous birds. American Journal
of Science, 3rd series. 3, 359-365.
Marsh, 1876. Notice of new Odontornithes. The American Journal of Science and
Arts. 11, 509-511.
Nessov and Prizemlin, 1991. A large advanced flightless marine bird of the order
Hesperornithiformes of the Late Senonian of Turgai Strait - the first finding
of the group in the USSR. USSR Academy of Sciences, Proceedings of the Zoological
Institute. 239, 85-107 (in Russian).
Bogdanovich, 2003. Morphologic aspect of phylogeny of Hesperornithidae (Ornithurae,
Aves). Vestnik zoologii. 37(6), 65-71.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286: 1-179.
Wilson and Chin, 2008. Bone histology of hesperornithiforms (Aves) from Late
Cretaceous greenhouse high-latitude environments. Journal of Vertebrate Paleontology.
28(3), 160A-161A.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
Brodavidae Martin, Kurochkin and Tokaryk, 2012
Definition- (Brodavis americanus <- Hesperornis regalis) (Martyniuk,
2012)
References- Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage
of diving birds from the Late Cretaceous of North America and Asia. Palaeoworld.
21(1), 59-63.
Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs.
Vernon, New Jersey. Pan Aves. 189 pp.
Potamornis Elzanowski, Paul and
Stidham, 2001
P. skutchi Elzanowski, Paul and Stidham, 2001
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 73103) quadrate (18 mm)
Referred- ?(AMNH 22002; Lancian Ornithurine D) proximal coracoid (Longrich, Tokaryk and Field, 2011)
?(University of Nebraska coll.) tarsometatarsus (Elzanowski,
Paul and Stidham, 2001)
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, Montana, US
Referred- ?(UCMP 117605) tarsometatarsus (Elzanowski, Paul and Stidham,
2001)
?(UCMP 13355; Lancian Hesperornithiform A) tarsometatarsus (Longrich, Tokaryk and Field, 2011)
?(UCMP 159207) distal tarsometatarsus (UCMP online)
?(UCMP 159208) femur (UCMP online)
?(UCMP 174715) tibiotarsus (UCMP online)
?(UCMP 174718) dorsal vertebra (UCMP online)
?(UCMP 187203) tarsometatarsus (UCMP online)
?(UCMP 187205) vertebra (UCMP online)
?(UCMP 187206) vertebra (UCMP online)
?(UCMP 187207; Lancian Ornithurine D) proximal coracoid (Longrich, Tokaryk and Field, 2011)
Diagnosis- (after Elzanowski et al., 2001) distinct medial depression
for m. protractor pterygoidei et quadrati dorsal to orbital process.
(after Longrich et
al., 2011) (for Lancian Ornithurine D) shallowly concave, subtriangular scapular facet; short,
deep, and weakly hooked acrocoracoid process; coracoid shaft
mediolaterally compressed and bowed dorsally; procoracoid hooked
ventrally around the triosseal canal; glenoid lateral to scapular
cotyle.
(for Lancian Hesperornithiform A) short, broad metatarsus;
metatarsal IV subequal in length to metatarsal III; dorsal flange of
metatarsal IV does not extend the full length of the metatarsus; distal
metatarsus not twisted relative to proximal metatarsus; large and
proximally located depression for reception of metatarsal I.
Other diagnoses- Elzanowski et al. (2001) list the strongly asymmetrical
quadrate head, with the beak-shaped medial part overhanging the otic process
as an apomorphy, but note it is also present in most palaeognaths, Psophia,
Cariama and Opisthocomus. Similarly, they list the presence of
a quadratojugal buttress as diagnostic, but then state it is also present in
Baptornis and Parahesperornis. A pit on the medial part of the
quadrate head and small orbital process are also present in Ichthyornis,
so are possibly plesiomorphies. Elzanowski et al. state the low angle between
the lateral and medial condyles is diagnostic, as those of Baptornis
and hesperornithids are higher, but that of Ichthyornis is even lower,
making it a probable plesiomorphy. The smooth connection between medial and
"posterior" condyles is plesiomorphic (Clarke, 2004), while contra
Elzanowski et al., the lateral condyle is separated from the posterior articular
surface by a groove.
Comments- Elzanowski et al. (2001) do not describe the tentatively referred
paratype tarsometatarsi, merely stating they are the right size to belong to
Potamornis. The UCMP specimens are identified as Potamornis
in the UCMP collections, but cannot be compared to the holotype. UCMP
159208, 187205 and 187206 are from the Danian (Paleocene), so were
presumably reworked. The coracoids were called Lancian Ornithurine D by
Longrich et al. (2011), who recovered it sister to Ichthyornis
using Clarke's bird matrix. He suggested it "appears to be closely
related to Judithian Ornithurine A" and that "both morphotypes closely
resemble coracoids described from the Carrot River Formation of
Saskatchewan", which have since been referred to Pasquiaornis. Coracoid RSM P2992.1 is tentatively referred to Brodavis sp. nov. here while AMNH 22002 may be Potamornis based on provenence and UCMP 187207 could be Potamornis or Brodavis? baileyi. Indeed, it's probable Potamornis and Brodavis refer to the same concept, and the Hell Creek material listed here might all be better referred to Brodavis? baileyi.
Then again, Lancian Ornithurine D coracoids seem to be from a smaller
species than Lancian Hesperornithiform A tarsometatarsi (B? baileyi-sized), and two distinctly sized species are present in the Frenchman Formation. Which size class the Potamornis type quadrate falls into is unknown and none of the tarsometatarsi listed as Potamornis here have been described or figured so cannot be compared to Brodavis species.
While
the lack of pneumaticity and quadratojugal buttress suggests Potamornis
is a hesperornithine, the lack of and elongate orbital process excludes it from
the Parahesperornis + Hesperornis clade.
References- Elzanowski, Paul and Stidham, 2001. An avian quadrate from
the Late Cretaceous Lance Formation of Wyoming. Journal of Vertebrate Paleontology.
20(4), 712-719.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis
and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum
of Natural History. 286, 1-179.
Longrich, Tokaryk and Field, 2011. Mass extinction of birds at the Cretaceous-Paleogene
(K-Pg) boundary. Proceedings of the National Academy of Sciences. 108(37), 15253-15257.
Brodavis Martin, Kurochkin and Tokaryk, 2012
Comments- Nessov (1992) first commented on the possibility of small volant
hesperornithines based on small elements in North American museums from the
Late Campanian and Maastrichtian of the US and Canada. No details were given,
but Martin et al. (2012) eventually described these tarsometatarsi including
one from the Nemegt Formation previously described by Kurochkin (2000) as species
of the new genus Brodavis. Further study will be necessary to determine
whether the diagnosis provided by Martin et al. includes synapomorphic characters,
or merely symplesiomorphies, and thus whether B? baileyi, B? varneri
and B? mongoliensis are properly referred to this genus. Bell and Chiappe
(2016) did find baileyi and varneri to group together in their
phylogenetic analysis, but did not test the type species B. americanus
or mongoliensis. It's likely material assigned to Potamornis belongs here as well, which may move the clade stemward of Baptornis.
References- Nessov, 1992. [Flightless birds of meridional Late Cretaceous
sea straits of North America, Scandinavia, Russia and Kazakhstan as indicators
of features of oceanic circulation.] Byulleten Moskovskogo Obshchestva Ispytatelet
Prirody Otdel Geologicheskii. 67, 78-83.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage of diving birds
from the Late Cretaceous of North America and Asia. Palaeoworld. 21(1), 59-63.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
B. americanus Martin, Kurochkin
and Tokaryk, 2012
Late Maastrichtian, Late Cretaceous
Frenchman Formation, Saskatchewan, Canada
Holotype- (RSM P2315.1; Lancian Hesperornithiform A) incomplete tarsometatarsus (~34 mm)
Referred- ?(RSM MB.AV.705; Lancian Hesperornithiform A) tarsometatarsus (Longrich, Tokaryk and Field, 2011)
Diagnosis- (after Martin et al., 2012) facet for metatarsal one placed
below the middle of tarsometatarsus; metatarsal shaft broader and more robust
than in B. baileyi but is smaller and less robust than B? varneri;
trochlea for digit IV swollen proximally, being slightly broader than the trochlea
for digit III, with broad and flat anterodistal surface.
Comments- Longrich et al.
(2011) described three tarsometatarsi as Lancian Hesperornithiform A,
noting similarity to what would be named Brodavis? mongoliensis the following year. One (RSM P2315.1) was described as Brodavis americanus by Martin et al. (2012), and another (RSM MB.AV.705) is tentatively assigned to B. americanus
here based on provenance and size. Note Longrich et al. also
propose a second smaller species Lancian Hesperornithiform B from the
same formation.
References- Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage
of diving birds from the Late Cretaceous of North America and Asia. Palaeoworld.
21(1), 59-63.
Longrich, Tokaryk and Field, 2011. Mass extinction of birds at the Cretaceous-Paleogene
(K-Pg) boundary. Proceedings of the National Academy of Sciences. 108(37), 15253-15257.
B? baileyi Martin, Kurochkin and
Tokaryk, 2012
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, South Dakota, US
Holotype- (USNM 50665) incomplete tarsometatarsus
Diagnosis- (after Martin et al., 2012) shaft of the tarsometatarsus more
slender than in B. americanus with trochlea for digit IV less expanded
at base; trochlea for digit II more elevated proximally at base and placed more
behind trochlea for digit III; outer anterior ridge of shaft extending more
distally; proximal nutrient foramina reduced practically to absence.
Comments- Note some of the Hell Creek Potamornis material may belong to
this species, particularly similarly-sized tarsometatarsus UCMP 13355.
Reference- Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage
of diving birds from the Late Cretaceous of North America and Asia. Palaeoworld.
21(1), 59-63.
B? varneri (Martin and Cordes-Person,
2007) Martin, Kurochkin and Tokaryk, 2012
= Baptornis varneri Martin and Cordes-Person, 2007
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, South Dakota, US
Holotype- (SDSM 68430) (adult) anterior (~3-6) cervical vertebra, mid (~7-10)
cervical vertebra, fourteenth cervical vertebra, fifteenth cervical vertebra,
sixteenth cervical vertebra, seventeenth cervical vertebra, posterior cervical
or anterior dorsal vertebrae, first dorsal vertebra, two dorsal ribs, posterior
synsacrum, posterior ilia, pubes, ischia, partial femora, tibiotarsus (206.47
mm), fibula, tarsometatarsus (96.13 mm)
Diagnosis- (after Martin and Cordes-Person, 2007) tarsometatarsus more
robust than other hesperornithines.
Other diagnoses- Martin and Cordes-Person (2007) list elongate cervical
vertebrae as a character of this species, but they are shorter than in B.
advenus. The capitulum and tuberculum of the illustrated dorsal rib are
similarly placed to B. advenus, not necessarily more separated as stated
by the authors, especially when one considers that only two proximal rib portions
are photographed for B. advenus. The indistinct antitrochanter is a plesiomorphy
shared with Enaliornis barretti, while the open acetabulum is
also a plesiomorphy shared with taxa such as Ichthyornis and Apsaravis.
The well separated pubis and ischium is a plesiomorphy found in Enaliornis,
Parahesperornis and Hesperornis. The proximolateral ischial fossa
is said to be more shallow than in B. advenus and Hesperornis,
but does not seem so in the photo. A broad popliteal fossa is primitive, being
present in Enaliornis, Hesperornis and Pasquiaornis? tankei
(but perhaps not P. hardiei), whereas the fossa does not appear smoother
in varneri than in other hesperornithines. A shallow popliteal fossa
is also present in Enaliornis, while a wide intercondylar fossa is also
present in Enaliornis and Hesperornis. The prominent medial femoral
condyle is also present in Enaliornis? sedgwicki, and the lateral condyle
does not appear more "high and distinct" than in B. advenus.
The anteroposteriorly expanded proximal tibiotarsus and elongate fibular crest
(~59% of tibiotarsal length) are shared with Hesperornis. The straightness
of the fibular crest might refer to the fact it doesn't seem to curve distally
onto the anterior shaft as in B. advenus, but polarity is difficult to
establish. Enaliornis shares the shallow proximolateral fossa for the
fibula, making the opposite state a possible apomorphy of B. advenus.
Contra Martin and Cordes-Person, the distal tibiotarsus does not curve medially
more than in B. advenus. Proximal foramina are present in Parahesperornis
and Hesperornis as well (and Pasquiaornis? tankei), as noted in
the description of FHSM VP-17312, making the reported absence in B. advenus
probably due to incomplete preparation. Elongate intertrochlear grooves are
also found in Enaliornis, Pasquiaornis, Parahesperornis
and Hesperornis, making their absence an apomorphy of B. advenus.
The tarsometatarsi of all hesperornithines are waisted transversely just proximal
to trochlea II as in varneri.
Comments- This specimen was discovered in 1991 and first published in
an abstract by Martin and Varner (1992), to be formally described and named
by Martin and Cordes-Person (2007). While most published references refer the
species to Baptornis, this is based on a mix of symplesiomorphies and
synapomorphies of more inclusive clades as noted in the Baptornis other
diagnoses section. In contrast, there is some support for placing this species
as the basalmost hesperornithid, as seen in the Hesperornithidae diagnosis above.
Martin et al. (2012) included it in their new genus Brodavis based on
"overall shape of the tarsometatarsus" and the symplesiomorphic small
metatarsal IV trochlea compared to Hesperornis. As this is vague and
problematic reasoning and the authors themselves state it "should probably
have its own generic designation", this assignment is provisional. However,
Bell and Chiappe (2016) did recover a phylogeny similar to my unpublished one
where varneri is a basal hesperornithid, and found Brodavis? baileyi
to be its sister group. The Brodavis type species B. americanus
was not included though, making it still uncertain whether varneri should
be referred to that genus.
References- Martin and Varner, 1992. The highest stratigraphic occurrence
of the fossil bird Baptornis. Proceedings of the South Dakota Academy
of Science. 71, 167 (abstract).
Person and Martin, 2004. A new species of the diving bird Baptornis (Ornithurae:
Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous) of
southwestern South Dakota. Geological Society of America Abstracts with Programs.
36(4), 80.
Martin and Cordes-Person, 2007. A new species of the diving bird Baptornis
(Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous)
of southwestern South Dakota. The Geological Society of America, Special Paper.
427, 227-237.
Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage of diving birds
from the Late Cretaceous of North America and Asia. Palaeoworld. 21(1), 59-63.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
B? mongoliensis Martin, Kurochkin
and Tokaryk, 2012
Late Campanian-Early Maastrichtian, Late Cretaceous
Bugin Tsav, Nemegt Formation, Mongolia
Holotype- (PIN 4491-8) incomplete tarsometatarsus (Kurochkin, 2000)
Diagnosis- (after Martin et al., 2012) external cotyla in proximal head
of the tarsometatarsus expands anteroposteriorly, with anterior and posterior
parts inclined distally; proximal nutrient foramina are well developed; metatarsal
facet for digit I placed almost in the middle of the tarsometatarsus; metatarsal
shaft slender; transverse section in the middle of shaft close to quadrangular.
Comments- The holotype was discovered in 1987. Kurochkin (2000) described
it and mentioned a small mandible and cervical vertebra which were "somewhat
different" from other hesperornithines. He referred these to "Hesperornithiformes
fam. nov." though he did not list any diagnostic characters. Kurochkin
also related these to small hesperornithine remains from the Zhuralovskaya Svita
(Mourer-Chauvire, 1992), which are presently undescribed and generally referred
to Baptornithidae. The mandible and vertebral may be the same taxon as B.
mongoliensis and IGM 100/1311, which are of similar size and also have thinner
bone walls than Baptornis or Hesperornis.
References- Kurochkin, 2000. Mesozoic birds of Mongolia and the former
USSR. in Benton, Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs
in Russia and Mongolia. 533-559.
Martin, Kurochkin and Tokaryk, 2012. A new evolutionary lineage of diving birds
from the Late Cretaceous of North America and Asia. Palaeoworld. 21(1), 59-63.
B. sp. nov. (Longrich, Tokaryk and Field, 2011)
Late Maastrichtian, Late Cretaceous
Frenchman Formation, Saskatchewan, Canada
Material- (RSM P2604.1; Lancian Hesperornithiform B) (adult) partial tarsometatarsus (Longrich, Tokaryk and Field, 2011)
(RSM P2992.1; Lancian Ornithurine D) proximal coracoid
Comments- Longrich et al.
(2011) propose Lancian Hesperornitiform B for a tarsometatarsus
"identical to" but much smaller than what was later named Brodavis americanus. The coracoids RSM P2992.1 was called Lancian Ornithurine D by
Longrich et al. (2011), who recovered it sister to Ichthyornis
using Clarke's bird matrix. He suggested it "appears to be closely
related to Judithian Ornithurine A" and that "both morphotypes closely
resemble coracoids described from the Carrot River Formation of
Saskatchewan", which have since been referred to Pasquiaornis. As its estimated mass is closer to Lancian Hesperornithiform B, it is referred to that species here.
Reference-
Longrich, Tokaryk and Field, 2011. Mass extinction of birds at the Cretaceous-Paleogene
(K-Pg) boundary. Proceedings of the National Academy of Sciences. 108(37), 15253-15257.
B? sp. (Aotsuka, Hatcher, Janzic and Sato, 2012)}
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
Material- (CFDC B.08.01.15) distal femur
Comments- Initially identified as Baptornis advenus by Aotsuka
et al. (2012), Aotsuka and Sato (2016) later described this specimen as Brodavis
sp.. As only B. varneri includes femoral material, it cannot be compared
to other species, though B. varneri matches in size and stratigraphy.
References- Aotsuka, Hatcher, Janzic and Sato, 2012. Diversity of the
Hesperornithiformes (Aves) from the Upper Cretaceous Pierre Shale in Southern
Manitoba, Canada. Journal of Vertebrate Paleontology. Program and Abstracts
2012, 57.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
B? sp. (
Tanaka, Takasaki, Chiba, Hayashi, Brink, Buuvei and Tsogtbaatar, 2021)
Early Maastrichtian, Late Cretaceous
White Beds of Khermeen Tsav, Nemegt Formation, Mongolia
Material- distal tarsometatarsus
Comments- Tanaka et al. (2021)
report this tarsometatarsus "shows the following features unique to
non-hesperornithid hesperornithiforms: (1) the proximally positioned
distal edge of metatarsal trochlea II which does not reach the base of
metatarsal trochlea IV; (2) metatarsal trochleae III and IV which
distally extend to a similar level; and (3) the equally mediolaterally
wide metatarsal trochleae III and IV. Additionally, the broad and flat
anterodistal surface of the tarsometatarsus suggests this specimen can
be tentatively assigned to Brodavis sp." It notably differs from B. americanus in having thinner bone walls (relative cortical bone thickness 66.7% vs. 84.9%). While they did not compare it to B. mongoliensis
from the same formation, only a middle fourth of the shaft from above
the distal vascular foramen to the hallucial facet are preserved in
both, with metatarsal II's trochlea broken off in B. mongoliensis. That being said, both are more slender than B. americanus but the Khermeen Tsav specimen is about 50% larger so may be a different species.
Reference- Tanaka, Takasaki, Chiba, Hayashi, Brink, Buuvei and Tsogtbaatar, 2021.
A hesperornithiform from the Upper Cretaceous Nemegt Formation in the
Gobi Desert of southwest Mongolia: Implications for paleonecology of
island hesperornithiforms. The Society of
Vertebrate Paleontology Virtual Meeting Conference Program, 81st Annual
Meeting. 248-249.
unnamed clade (Fumicollis hoffmani + Hesperornis regalis)
Diagnosis- (proposed) deep proximodorsal metatarsal III fossa.
Fumicollis Bell and Chiappe,
2015
F. hoffmani Bell and Chiappe, 2015
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Holotype- (UNSM 20030) sixteenth cervical vertebra (16.9 mm), seventeenth
cervical vertebra (15.3 mm), first dorsal vertebra (16.7 mm), incomplete second
dorsal vertebra (16.5 mm), incomplete third dorsal vertebra (15.9 mm), incomplete
fourth dorsal vertebra (16.7 mm), partial fifth dorsal vertebra, sixth dorsal
vertebra (14 mm), four dorsal ribs, six uncinate processes, five mid caudal
vertebrae (lost?), incomplete pygostyle, partial coracoid (lost?), partial sternum
(lost?), four sternal ribs (lost?), incomplete humerus (lost?), pelves (one
incomplete, one partial; ilium ~198.04 mm), femur (71.8 mm), patella (21.11 mm), tibiotarsi (one
partial; 193.82 mm), fibula, tarsometatarsus (83.72 mm), phalanx II-1 (37.4 mm),
phalanges III-1 (37.77 mm), phalanges III-2 (25.8 mm), phalanx III-3 (24.4 mm),
pedal skin impression, cololites
Diagnosis- (after Bell and Chiappe, 2015) presacral vertebrae with expanded
hypapophyses; elongate pelvis with reduced acetabulum (acetabulum/pelvis ratio
9.6%); moderately expanded trochanteric crest (transverse extent nearly half
of midshaft width); expanded lateral femoral condyle (transverse extent of condyle
over 75% of midshaft width; tibiotarsus with triangular cnemial expansion; medial
cnemial crest extended to midshaft; patella pyramidal with flattened posterior
face; patella perforated for ambiens tendon; fibula with posteriorly expanded
proximal end; slightly depressed, saddle-shaped articular surface of fibula;
tarsometatarsus with shingled metatarsals; distinct dorsal ridge of tarsometatarsus
formed by entire length of metatarsal IV; tarsometatarsus with reduced and plantarly
displaced trochlea II; enlarged medial trochlear ridge of metatarsal IV; phalanx
III-1 narrow mediolaterally; greatly expanded, curved medial face of distal
pedal phalanx III-1.
Comments- UNSM 20030 was discovered in 1936, but not described until
1976 by Martin and Tate. Bell and Chiappe (2016, online 2015) found it was actually a more
derived taxon sister to Parahesperornis+Hesperornis and described
it as a new genus and species later that year (2015). Bell and Chiappe did
not mention the free caudals, pectoral elements or humerus described by Martin
and Tate, and reidentified the six pedal phalanges. Bell (pers. comm., 2016)
stated she didn't know "if the material has been lost or was incorrectly
attributed to 20030", but that it wasn't catalogued with that number when
she examined it. The cololites include a jaw of the fish Enchodus cf.
parvus.
References- Martin and Tate, 1976. The skeleton of Baptornis advenus
(Aves: Hesperornithiformes). in Olson (ed). Collected papers in avian phylogeny
honoring the 90th birthday of Alaxander Wetmore. Smithsonian Contributions to
Paleobiology. 27, 35-66.
Bell and Chiappe, 2015. Identification of a new hesperornithiform from the
Cretaceous Niobrara Chalk and implications for ecologic diversity among early
diving birds. PLoS ONE. 10(11), e0141690.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Hesperornithidae sensu Bell and Chiappe, 2020
Definition- (Parahesperornis alexi + Hesperornis regalis)
Diagnosis- (proposed) elongate orbital process on quadrate (unknown in
Brodavis and Fumicollis); coracoid tubercle distal to glenoid
(unknown in Brodavis); humerus extremely slender (unknown in Brodavis);
short preacetabular process; metatarsal IV trochlea >140% as wide as trochlea
III; crescent and peg articulations between phalanges in pedal digit IV (unknown
in Brodavis and Fumicollis).
Comments- This clade correlates to the Hesperornithidae of Martin (1984),
which he supported with the cresecent and peg articulations in pedal digit IV.
References-
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
Hesperornithidae indet. (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
Material- (CFDC B.00.43.00) ilium (Aotsuka and Sato, 2016)
(CFDC B.00.57.00; lost) synsacrum (Aotsuka and Sato, 2016)
(CFDC B.07.04.23) two vertebrae, patella (Aotsuka and Sato, 2016)
(CFDC B.09.02.13) ilium (Aotsuka and Sato, 2016)
(CFDC B.80.09.16) ilium (Aotsuka and Sato, 2016)
(CFDC B.82.04.03) ilium (Aotsuka and Sato, 2016)
(CFDC B.2010.01.03) ilium (Aotsuka and Sato, 2016)
(FMNH PA290; in part) nine vertebrae, ilium (Aotsuka and Sato, 2016)
(ROMM coll.; lost) synsacrum (Aotsuka and Sato, 2016)
Comments- Aotsuka and Sato (2016) referred these to Hesperornithidae
indet., which in their taxonomy excludes Brodavis. It presumably also
excludes Fumicollis, as the latter genus has a patella similar to Baptornis
and a pelvis that was the basis of Baptornis' anatomy until Fumicollis
was excluded from the genus.
Reference-
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
Parahesperornis Martin, 1984
= "Parahesperornis" Martin, 1983
P. alexi Martin, 1984
= "Parahesperornis alexi" Martin, 1983
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Holotype-
(KUVP 2287) (subadult) incomplete skull, mandibles (208 mm), axis,
third cervical vertebra, fourth cervical vertebra, fifth cervical
vertebra, sixth cervical vertebra, seventh cervical vertebra, eighth
cervical vertebra, ninth cervical vertebra, tenth cervical vertebra,
eleventh cervical vertebra, twelfth cervical vertebra, thirteenth
cervical vertebra, fourteenth cervical vertebra, fifteenth cervical
vertebra, sixteenth cervical vertebra, seventeenth cervical vertebra,
first dorsal vertebra, second dorsal vertebra, third dorsal vertebra,
fourth dorsal vertebra, fifth dorsal vertebra, sixth dorsal vertebra,
several dorsal rib fragments, several uncinate processes, synsacrum,
four caudal vertebrae, incomplete coracoid, partial sternum, sternal
ribs(?), partial humeri, pelves (ilium ~237.63 mm),
femora (68.8 mm), patellae (44.61 mm; one incomplete), tibiotarsi
(212.97 mm), fibula (130.71 mm), tarsometatarsi (100.73 mm), phalanges
I-1, pedal ungual I, phalanges II-1,
phalanges II-2, pedal unguals II, phalanges III-1 (31.14 mm), phalanx
III-2, phalanx
III-3, pedal unguals III, phalanges IV-1 (29.17 mm), phalanges IV-2,
phalanges IV-3, phalanges IV-4, pedal
unguals IV, feathers(?), pedal scales (Williston, 1896)
Paratype- partial tarsometatarsus (Wetmore, unpublished MS)
Referred- (FHSM VP-17312) tarsometatarsus (99.93 mm) (Bell and Everhart,
2009)
(KUVP 24090) posterior mandible (lost?), incomplete fourth cervical
vertebra, incomplete fifth cervical vertebra, incomplete ~sixth/seventh
cervical vertebra, cervical vertebra, eleventh cervical vertebra,
twelfth cervical vertebra, thirteenth cervical vertebra, fourteenth
cervical vertebra, fifteenth cervical vertebra, sixteenth cervical
vertebra, seventeenth cervical vertebra, first dorsal vertebra, second
dorsal vertebra, third dorsal vertebra, fourth dorsal vertebra, fifth
dorsal vertebra, sixth dorsal vertebra, partial dorsal ribs, uncinate
processes, sacrum, four caudal vertebrae, pygostyle, coracoid (55.38 mm), sternum,
pelves (ilium 246.6 mm), femora (74.53 mm), patellae (56.54 mm), tibiotarsi (230.94 mm), fibulae (Witmer, 1990)
(RMDRC coll.) pelvis (Anthony, pers. comm., 2009)
Diagnosis- (after Bell and
Chiappe, 2020) premaxillae short (width across the premaxillae at the
nares is approximately 35% the pre-nares length); lacrimal elongate
with long ventral process that terminates in a flattened face; frontals
flattened and very wide (width roughly 75% the length of the frontals);
interfrontal suture forms deep groove; arched frontoparietal suture;
reduced pneumaticity of the braincase; deep notch separating the
zygomatic process and paraoccipital process; prominent paraoccipital
processes; narrow and deep basisphenoid recess; suture between
basioccipital and basisphenoid on basal tubera; small occipital
condyle; posteromedial depression present on quadrate; lateral crest of
quadrate restricted to lateral margin; pterygoid triangular with
flattened faces; articulation of the angular with dentary along a broad
surface; surangulars convex laterally; expanded retroarticular process
of the articular; anterior cervical vertebrae elongate while
posterior cervical vertebrae become more compact; triangular coracoid
with elongate neck; flat sternum with five costal processes; humerus
reduced with only poorly defined condyles; elongate pelvis with
reduced, circular acetabulum (acetabulum diameter approximately 10%
ilium length); head of femur extends proximally past trochanter; femur
slightly waisted, with expanded trochanter and fibular condyle; lateral
condyle of femur extends only slightly distally past medial condyle;
elongate, triangular patella (distal mediolateral width approximately
50% of the proximodistal length); tibiotarsus with triangular cnemial
expansion; medial face of fibula with triangular depression;
tarsometatarsus with shingled metatarsals, proximal articular surface
rhombic in proximal view; rounded intercotylar eminence of
tarsometatarsus; trochlea IV extending slightly further distally than
trochlea III; phalanges of pedal digit IV robust, with unevenly sized
cotylae.
Other diagnoses- Lucas (1903) distinguished his Hargeria gracilis
(based on the holotype of Parahesperornis) from Hesperornis regalis
with two plesiomorphies- lacrimal ventral process slender; femur more elongate
and less proximally expanded. Contra Lucas, the nasal processes do not appear
shorter than H. regalis. While the orbital quadrate process is much longer
than H. regalis specimen YPM 1206 as illustrated by Marsh, it is not
much longer than the actual specimen of YPM 1206 or KUVP 71012, making this
difference invalid.
Martin (1984) stated Parahesperornis' skull was mesokinetic (has a flexible
frontoparietal joint), but this was later disproven by Buhler et al. (1988).
Two of the characters listed by Martin are plesiomorphies compared to Hesperornis
regalis- coracoid elongate; tarsometatarsal trochlea IV smaller and less
projected distally. Contra Martin, the anterior lacrimal process is less extended
anteriorly than in Hesperornis. Crescent and peg articulations on pedal
digit IV are shared with Hesperornis. The tibiotarsus is said to be less
compressed than Hesperornis, but without knowing the plane of depression
this is vague.
Comments- The holotype was discovered in 1894 and referred to Hesperornis
gracilis by Williston (1896, 1898). Lucas (1903) described it as an example
of Hesperornis gracilis, using it to separate the species as Hargeria
gracilis. However, the ICZN dictates Hargeria must stay associated
with its type species regardless of what specimen its description was based
on. The mandible was illustrated by Gregory (1951, 1952) as Hesperornis gracilis
and Swinton (1975) as H. regalis, while a tooth was illustrated by Martin
et al. (1980) as "a hesperornithid." Gregory (1951) argued the differences
between regalis and KUVP 2287 were insufficient for generic separation,
partially caused by inaccuracies in Marsh's illustrations. In 1952, he argued
the quadrate was not disimilar when compared to the actual material instead
of Marsh's illustration and that femoral differences could be caused by crushing.
Gingerich (1973) described the skull and stated gracilis only differs
from regalis in being slightly smaller, while in 1976 he deferred identification
of KUVP 2287 to the species. Martin (1983) proposed the new taxon Parahesperornis
alexi
for KUVP 2287, but as Neas and Jenkinson (1986) note, it is not a
proper description as it lacks a diagnosis (ICZN Article 13.1.1). The
name is thus a nomen nudum until Martin's (1984) official description.
While Martin (1984) stated he had a full description in preparation,
one didn't appear until Bell and Chiappe (2020). Some cranial
morphologies were described by Buhler et al. (1988) and Witmer (1990).
Both Witmer and Elzanowski (1991) have noted various unfused cranial
sutures suggest it was not an adult but Bell and Chiappe say "compound
bone development is consistent with that of a fully-grown
individual." Williston described a patch of material associated
with pedal scales as feathers, but Bell and Chiappe find "it is not
possible to confirm his interpretation."
Martin (1984) mentions a partial tarsometatarsus of Parahesperornis which
was going to be described by Wetmore, but the paper was never completed.
KUVP 24090 was discovered in 1981. Witmer (1990) says it includes
a "fragment of the articular region of the right lower jaw", but this
is not mentioned by Bell and Chiappe in their description.
Bell and Everhart (2009) described tarsometatarsus FHSM VP-17312 as Parahesperornis
sp., which is slightly more elongate with a smaller trochlea III (about half
the size of IV). It was referred to P. alexi by Bell and Chiappe (2020). As it was discovered in the early 1990s, this cannot be the specimen Martin mentioned.
References- Williston, 1896. On the dermal covering of Hesperornis.
Kansas University Quarterly. 5(1), 53-54.
Williston, 1898. Birds. The University Geological Survey of Kansas, Part 2.
4, 43-53.
Lucas, 1903. Notes on the osteology and relationships of the fossil birds of
the genera Hesperornis, Hargeria, Baptornis, and Diatryma.
Proceedings of the United States National Museum. 26, 545-556.
Gregory, 1951. Convergent evolution: The jaws of Hesperornis and the
mosasaurs. Evolution. 5, 345-354.
Gregory, 1952. The jaws of the Cretaceous toothed birds Ichthyornis and
Hesperornis. Condor. 54(2), 73-88.
Gingerich, 1973. Skull of Hesperornis and early evolution of birds. Nature.
243, 70-73.
Swinton, 1975. Fossil Birds. 3rd Ed. British Museum (Natural History), London.
1-81.
Gingerich, 1976. Evolutionary significance of the Mesozoic toothed birds. Smithsonian
Contributions to Paleobiology. 27, 23-34.
Martin, Stewart and Whetstone, 1980. The origin of birds: structure of the tarsus
and teeth. The Auk. 97, 86-93.
Martin, 1983. The origin and early radiation of birds. in Bush and Clark (eds).
Perspectives in Ornithology. Cambridge University Press, Cambridge. 291-338.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Neas and Jenkinson, 1986. Type and figured specimens of fossil vertebrates in
the collection of the University of Kansas Museum of Natural History, Part III.
Fossil birds. Miscellaneous Publication 78, Museum of Natural History, University
of Kansas, Lawrence. 1-14.
B�hler, Martin and Witmer, 1988. Cranial kinesis in the Late Cretaceous
birds Hesperornis and Parahesperornis. The Auk. 105, 111-122.
Witmer, 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological
Journal of the Linnaean Society of London. 100, 327-378.
Elzanowski, 1991. New observations on the skull of Hesperornis with reconstructions
of the bony palate and otic region. Postilla. 207, 20 pp.
Martin and Stewart, 1999. Implantation and replacement of bird teeth. Smithsonian
Contributions to Paleobiology. 89, 295-300.
Bell and Everhart, 2009. A new specimen of Parahesperornis (Aves: Hesperornithiformes)
from the Smoky Hill Chalk (Early Campanian) of Western Kansas. Transactions
of the Kansas Academy of Science. 112(1/2), 7-14.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
Hesperornis? mengeli Martin
and Lim, 2002
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, Manitoba, Canada
Holotype- (CFDC B.78.01.08; = BO 780108) tarsometatarsus (85.6 mm)
Other diagnoses- Martin and Lim (2002) diagnosed this based on its small
size, which is probably primitive and still larger than Hesperornis? macdonaldi.
The more slender shaft is also plesiomorphic. Trochlea III is not smaller compared
to IV than in Hesperornis crassipes and H. rossicus. Trochlea
II is more hidden behind III in H. crassipes, H. rossicus and H. bazhanovi.
Comments- This was described as a species of Hesperornis, but
its true position is more uncertain. The slender tarsometatarsus is more primitive
than the Baptornis + Hesperornis clade, while the small size is
unlike hesperornithids. However, the deep proximodorsal metatarsal III fossa
and enlarged metatarsal IV trochlea are shared with the Parahesperornis
+ Hesperornis clade. The distally projecting metatarsal IV is like Hesperornis,
but the rounded intercotylar process is not. The slender tarsometatarsus and
medial cotyla which is not transversely compressed suggests it is not part of
the large Hesperornis clade. It is here tentatively assigned to the Parahesperornis
+ Hesperornis clade, where it may be an extremely basal species of Hesperornis.
Bell and Chiappe (2016) found it to group with other Hesperornis species
in their analysis. They also noted the specimen number of the holotype is BO
780108, not BO 780106 as reported by Martin and Lim.
References- Martin and Lim, 2002. New information on the hesperornithiform
radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
of the Society of Avian Paleontology and Evolution. 165-174.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
Canadaga Hou, 1999
C. arctica Hou, 1999
Middle Maastrichtian, Late Cretaceous
Bylot Island, Nunavut, Canada
Holotype- (NMC 41050) incomplete fifteenth cervical vertebra, sixteenth
cervical vertebra (28 mm), partial seventeenth cervical vertebra
Paratypes- ?(NMC 41053) (juvenile) femoral shaft
?(NMC 41054) (juvenile) femoral shaft
?(NMC 41064) (juvenile) last synsacral vertebra (29 mm)
Coniacian, Late Cretaceous
Kanguk Formation, Nunavut, Canada
Referred- (NUVF 284) sixteenth cervical vertebra (26.3 mm), seventeenth
cervical vertebra (25.5 mm), incomplete first dorsal vertebra (26.7 mm), rib
fragments (Wilson et al., 2009; described in Wilson et al., 2011)
Diagnosis- (after Hou, 1999) posterior cervical centrum expanded transversely
to be wider than interzygapophyseal width; lateral fossa occupies entire posterior
cervical centrum; large hypapophysis, extending from anterior rim to middle
of centrum; angle between posterior cervical postzygapophyses much less than
90 degrees; short posterior cervical neural spines; well developed anterior
ligament fossa on posterior cervical vertebrae.
(after Wilson et al., 2009) fovea between the parapophysis and centrum with
a deep cavity below the transverse process.
Comments- Hou studied the type remains in 1991 and described them in
1999 as a new taxon of hesperornithid- Canadaga arctica. While the diagnosis
does distinguish Canadaga from Baptornis advenus and Hesperornis
regalis, the remains of other hesperornithines are either not comparable
or not described/illustrated well enough to compare. The size (estimated tarsometatarsal
length of 212 mm) is greater than other hesperornithids, which suggests it may
be referrable to the subgroup of large Hesperornis species. However,
no other characters are presently known which could resolve where Canadaga
belongs within Hesperornithes.
References- Hou, 1999. New hesperornithid (Aves) from the Canadian Arctic.
Vertebrata PalAsiatica. 37(7), 228-233.
Wilson, Chin, Dyke and Cumbaa, 2009. A high-latitude hesperornithiform (Aves)
from Devon Island: Paleobiogeography and size distribution of North American
hesperornithiforms. Journal of Vertebrate Paleontology. 29(3), 202A.
Wilson, Chin, Cumbaa and Dyke, 2011. A high latitude hesperornithiform (Aves)
from Devon Island: Palaeobiogeography and size distribution of North American
hesperornithiforms. Journal of Systematic Palaeontology. 9(1), 9-23.
Wilson. 2012. Paleobiology of hesperornithiforms (Aves) from the
Campanian Western Interior Seaway of North America, with analyses of
extant penguin bone histology. PhD thesis, University of Colorado. 150
pp.
Hesperornis Marsh, 1872a
= Lestornis Marsh, 1876
= Coniornis Marsh, 1893
= Hargeria Lucas, 1903
= Asiahesperornis Nessov and Prizemlin, 1991
Diagnosis- (proposed) hypertrophied ilial antitrochanter (also in Baptornis
advenus); acetabulum partially closed (also in Baptornis advenus);
pointed intercotylar process on tarsometatarsus (absent in Hesperornis crassipes);
metatarsal IV extends distally far beyond III (also in Enaliornis? seeleyi).
Comments- While numerous species and specimens have been referred to
Hesperornis, several have been given their own genera. Most of the literature
synonymizes Lestornis, Coniornis and Hargeria with Hesperornis,
but retains Asiahesperornis as a separate genus. Yet no reasons for excluding
the latter taxon from Hesperornis have been given, and it clades within
Hesperornis when included in a phylogenetic analysis (Bell and Chiappe,
2016; Mortimer, unpublished). Bell and Chiappe found all of these taxa to code
identically in their matrix and suggested the current named species diversity
is unsupported, though they did not create any new formal taxonomy. Hesperornis
mengeli and H. macdonaldi were named by Martin and Lim (2002), but
are here provisionally removed from the genus though Bell and Chiappe found
the first to only differ from other Hesperornis by one character and
the latter to code identically to other Hesperornis.
References- Marsh, 1872a. Discovery of a remarkable fossil bird. American
Journal of Science, Series 3. 3(13), 56-57.
Marsh, 1876. Notice of new Odontornithes. The American Journal of Science and
Arts. 11, 509-511.
Marsh, 1893. A new Cretaceous bird allied to Hesperornis. American Journal
of Science. 45, 81-82.
Lucas, 1903. Notes on the osteology and relationships of the fossil birds of
the genera Hesperornis, Hargeria, Baptornis, and Diatryma.
Proceedings of the United States National Museum. 26, 545-556.
Nessov and Prizemlin, 1991. A large advanced flightless marine bird of the order
Hesperornithiformes of the Late Senonian of Turgai Strait - the first finding
of the group in the USSR. USSR Academy of Sciences, Proceedings of the Zoological
Institute. 239, 85-107 (in Russian).
Martin and Lim, 2002. New information on the hesperornithiform
radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
of the Society of Avian Paleontology and Evolution. 165-174.
Wilson, 2012. The effects of climate and behavior on avian bone microstructure:
A comparative osteohistology study of hesperornithiforms from the Late Cretaceous
Western Interior Seaway. Journal of Vertebrate Paleontology. Program and Abstracts
2012, 195.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
H. bairdi Martin and Lim, 2002
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, South Dakota, US
Holotype- (YPM PU 17208A) synsacrum, incomplete ilium, proximal pubis, proximal
ischium, tarsometatarsus (102.4 mm)
Other diagnoses- Martin and Lim (2002) diagnosed this based on Hesperornis
characters (more enlarged and distally placed trochlea IV than Parahesperornis)
and its primitively small size (which is still larger than H? mengeli
and H? macdonaldi).
Comments- This taxon seems to be the most basal species of Hesperornis,
which explains its similarity to Parahesperornis. Bell and Chiappe (2016)
found it to group with Hesperornis in their analysis, differing from
other species in a single character.
Reference- Martin and Lim, 2002. New information on the hesperornithiform
radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
of the Society of Avian Paleontology and Evolution. 165-174.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
unnamed clade (Hesperornis regalis <- Hesperornis bairdi)
Diagnosis- (proposed) large size (proximal tarsometatarsal width over
25 mm); coracoid short proximodistally (unknown in H. bairdi); clavicles
unfused (unknown in other hesperornithines); interclavicular angle >70 degrees
(unknown in other hesperornithines); distal tibiotarsus not angled anteriorly
(unknown in H. bairdi); tarsometatarsus robust (less than 4.5 times longer
than proximally wide (also in Brodavis? varneri); medial tarsometatarsal
cotyla transversely compressed (also in Enaliornis? seeleyi).
Comments- This large Hesperornis clade may also include Canadaga,
based on its size.
H. altus (Marsh, 1893) Shufeldt,
1915b
= Coniornis altus Marsh, 1893
Campanian, Late Cretaceous
Claggett Shale or Judith River Formation, Montana, US
Holotype- (YPM 515) (adult) distal tibiotarsus
Campanian-Maastrichtian, Late Cretaceous
Pierre Shale Group, South Dakota, US
Referred- ?(YPM PU 17208C) posterior dorsal vertebra, synsacrum, ilium,
femur (YPM online)
?(YPM PU 17208D) tibiotarsus, metatarsal I, tarsometatarsus, seven pedal phalanges including III-1 (39.2 mm) (YPM online)
?(YPM PU 18589) cranial material, cervical vertebrae, dorsal vertebrae,
clavicle, sternal fragments, femur (81.9 mm), patellae, tibiotarsus
(Wilson, Chin and Cumbaa, 2016)
Diagnosis- indeterminate relative to H. regalis.
Comments- This specimen was discovered in 1892 and described by Marsh
(1893) as a new taxon of hesperornithine, which he named Coniornis altus.
This was based on two characters- lateral condyle projects distally further
than medial condyle; medial condyle does not extend medially past shaft. Shufeldt
(1915a) believed Marsh only separated Coniornis from Hesperornis
on stratigraphic grounds, though he did not officially place altus in
Hesperornis. Shufeldt (1915b) compared the element to Hesperornis
regalis and found them similar enough to place in the same genus, or even
the same species. He noted "where the condylar crests are more prominent
in Hesperornis, they have been broken off in Marsh's Coniornis altus."
He thus synonymized Coniornis with Hesperornis, which was followed
by Martin (1984) due to the compressed distal end. Indeed, comparing the holotype
to H. regalis, the two characters described by Marsh could be eliminated
by rotating the distal end of altus' tibiotarsus so that the condyles
are vertical instead of medially tilted. There is an obvious plaster filled
area just proximal to the condyles where misalignment could have taken place.
Once this is corrected for, the tibiotarsi are extremely similar. YPM 515 seems
to have a more anteriorly projected lateral condyle, but this would again be
solved by rotating the distal area. The lack of a medial epicondyle on YPM 515
could be due to damage.
Shufeldt (1915a) described Hesperornis montana from a dorsal vertebra
found in the Claggett Shale of Montana and considered the possibility YPM 515
was from the same beds (as the area was not well segregated when it was collected),
but felt it more likely that the size difference indicated there were two species
present. They are here kept separate as many formations have more than one hesperornithid
species, and there is no overlapping material.
The referred material from the
Pierre Shale Group may be H. bairdi, H. chowi, H? macdonaldi
or H? mengeli based on stratigraphy. Martin et al. (2016) describe a pathology on YPM PU 17208D (as Hesperornis sp. YPM PU 17208), noting it "is smaller than the common Hesperornis regalis of the Niobrara Chalk, but it differs from the slender limbed, contemporary H. chowi by having a broader tarsometatarsus with a more enlarged outer trochlea."
References- Marsh, 1893. A new Cretaceous bird allied to Hesperornis.
American Journal of Science. 45, 81-82.
Shufeldt, 1915a. The fossil remains of a species of Hesperornis found
in Montana. The Auk. 32(3), 290-284.
Shufeldt, 1915b. Fossil birds in the Marsh Collection of Yale University. Transactions
of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Martin, Rothschild and Burnham, 2016. Hesperornis escapes plesiosaur attack. Cretaceous Research. 63, 23-27.
Wilson, Chin and Cumbaa, 2016. A new hesperornithiform (Aves) specimen
from the Late Cretaceous Canadian High Arctic with comments on
high-latitude hesperornithiform diet. Canadian Journal of Earth
Sciences. 53(12), 1476-1483.
H. montanus Schufeldt, 1915a
Early Campanian, Late Cretaceous
Claggett Shale, Montana, US
Holotype- (USNM 8199) sixth dorsal vertebra (Shufeldt, 1915a)
Diagnosis- (after Shufeldt, 1915a) lateral fossae extremely shallow in
dorsal centra.
Comments- Shufeldt (1915) reported on a dorsal vertebra discovered in
1914, which he sent to Lull for examination. Lull determined it most closely
matched the last dorsal vertebra of Hesperornis, differing only in minor
ways, most of which also varied between different spcimens of that genus. He
concluded it was referrable to Hesperornis, and only perhaps a new species
due to stratigraphy. Shufeldt noted it may have been found in the same beds
as Coniornis altus but thought it was too small to derive from the same
species, so named it Hesperornis montana. However, the ICZN dictates
it must be emmended to montanus, as Hesperornis is masculine.
Marsh (1893) earlier described Coniornis altus from what may be the same
beds and while Shufeldt considered the possibility of synonymy (as have later
authors), he felt it more likely that the size difference indicated there were
two species present. They are here kept separate as many formations have more
than one hesperornithid species, and there is no overlapping material.
References- Marsh, 1893. A new Cretaceous bird allied to Hesperornis.
American Journal of Science. 45, 81-82.
Shufeldt, 1915a. The fossil remains of a species of Hesperornis found
in Montana. The Auk. 32(3), 290-284.
H. gracilis Marsh, 1876
= Hargeria gracilis (Marsh, 1976) Lucas, 1903
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Holotype- (YPM 1473) incomplete tarsometatarsus (~130 mm), two pedal phalanges
Referred-
(YPM 1478) dorsal vertebrae, partial femur, partial tibiotarsus,
tarsometatarsi (one partial; 138 mm), phalanx III-1 (34.87 mm), phalanx
IV-1 (41 mm) (Marsh, 1880)
(YPM 1679) cervical vertebrae, dorsal
vertebrae, rib fragments, partial synsacrum, pelvis, femora (84.06 mm),
patella (~88.24 mm), tibiotarsi, fibula, tarsometatarsi (126.44 mm),
phalanx IV-1 (40.32 mm), two pedal phalanges (Marsh, 1880)
(YPM 55000) vertebrae, synsacrum, femora, tibiotarsi, tarsometatarsi and pedal
phalanges including III-1 (35.9 mm) (Bell, Irwin and Davis, 2015)
Other diagnoses- Marsh (1876) diagnosed H. gracilis as being smaller
and more slender than H. regalis, but these are plesiomorphies.
Comments- Martin (1984) incorrectly listed the holotype as YPM 1478 in
his figure 1, which is a specimen listed in two tables as H. gracilis
by Marsh (1880). The holotype was discovered in 1876 and briefly described by
Marsh that year, but it was not illustrated until Martin (1984). Williston (1896,
1898) referred KUVP 2287 to Hesperornis gracilis, but it was later made
the holotype of Parahesperornis alexi by Martin (1984). Lucas (1903)
also believed KUVP 2287 was referrable to gracilis and used it as the
basis for transferring that species to his new genus Hargeria. However,
the ICZN dictates Hargeria must stay associated with its type species
regardless of what specimen its description was based on. Lang (1973) placed
a species of leptocheliid tanaidacean Leptochelia rapax Harger, 1879
into the new genus Hargeria. Thus the crustacean Hargeria is preoccupied
by the bird Hargeria, contra Bell and Everhart (2009). Martin (1984)
synonymized Hargeria with Hesperornis, but retained gracilis
as a distinct species. The taxon needs to be described in detail to determine
how it compares to other Hesperornis species.
YPM 1679 was referred to H. gracilis by Marsh (1880), but only listed
as Hesperornis sp. by Chiappe (2002) and the YPM catalog. YMP 55000 is
listed as Hesperornis gracilis in the YMP catalog, but as Hesperornis
sp. by Bell, Irwin and Davis (2015).
References- Marsh, 1876. Notice of new Odontornithes. The American Journal
of Science and Arts. 11, 509-511.
Harger, 1879. Notes on New England Isopoda. Proceedings of the United States
National Museum. 79, 157-165.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Lucas, 1903. Notes on the osteology and relationships of the fossil birds of
the genera Hesperornis, Hargeria, Baptornis, and Diatryma.
Proceedings of the United States National Museum. 26, 545-556.
Lang, 1973. Taxonomische und phylogenetische Untersuchungen uber die Tanaidaceen
(Crustacea). 8. Die Gattungen Leptochelia Dana, Heterotanais G.O.
Sars und Nototanais Richardson. Dazu einige Bemerkungen uber die Monokonophora
und ein Nachtrag. Zoologica Scripta. 2, 197-229.
Martin, Stewart and Whetstone, 1980. The origin of birds: structure of the tarsus
and teeth. The Auk. 97, 86-93.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Chiappe, 2002. Basal bird phylogeny: Problems and solutions. In Chiappe and
Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 448-472.
Bell and Everhart, 2009. A new specimen of Parahesperornis (Aves: Hesperornithiformes)
from the Smoky Hill Chalk (Early Campanian) of Western Kansas. Transactions
of the Kansas Academy of Science. 112(1/2), 7-14.
Bell, Irwin and Davis, 2015. Hesperornithiform birds from the Late Cretaceous
(Campanian) of Arkansas, USA. Transactions of the Kansas Academy of Science.
118(3/4), 219-229.
H. chowi Martin and Lim, 2002
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, South Dakota, US
Holotype- (YPM PU 17208) tarsometatarsus (137.2 mm)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
Referred- (CFDC B.00.27.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.79.05.13) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.82.08.17) (2 individuals) two tarsometatarsi (Aotsuka and Sato, 2016)
(CFDC B.83.02.18) tarsometarsi (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Millwood Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.05.01.15) two tarsometatarsi (Aotsuka and Sato, 2016)
(CFDC B.05.01.23) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.07.02.23) tarsometatarsus (Aotsuka and Sato, 2016)
Diagnosis- (after Martin and Lim, 2002) medial anterior metatarsal ridge
blends into median groove distally.
Other diagnoses- Martin and Lim (2002) diagnosed Hesperornis chowi
with several characters that differ from H. regalis. However, the more
elongate tarsometatarsus and slender lateral anterior metatarsal ridge are plesiomorphic,
while the fourth trochlea is not more enlarged compared to trochlea III. A short
medial anterior metatarsal ridge is also present in Hesperornis mengeli
and H. bazhanovi.
Comments- Martin and Lim (2002) also believed remains described by Russell
(1967) as H. regalis from the Northwest Territories might be H. chowi,
but these are from a different formation.
References- Russell, 1967. Cretaceous vertebrates from the Anderson River,
N.W.T. Canadian Journal of Earth Sciences. 4, 21-38.
Martin and Lim, 2002. New information on the hesperornithiform
radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
of the Society of Avian Paleontology and Evolution. 165-174.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
H. lumgairi Aotsuka
and Sato, 2016
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
Holotype- (CFDC B.78.02.07; Hesperornis sp. A) (adult) incomplete
tarsometatarsus
Late Campanian, Late Cretaceous
Foremost Formation, Alberta, Canada
Paratype- (UA 9716) incomplete tarsometatarsus (147 mm)
Diagnosis- (after Aotsuka and Sato, 2016) lateral tarsometatarsus cotyle
only one third of medial cotyle [size?]; smooth and rounded posterior surface
of tarsometarasus shaft, giving D-shaped outline in proximal view; indistinct
triangular surface on posterior side of proximal tarsometatarsus.
Comments- The holotype was discovered in 1978, noted in Nicholls' (1988)
thesis and Aotsuka et al.'s (2012) thesis as Hesperornis sp. A, and described
as a new species by Aotsuka and Sato (2016).
UA 9716 was discovered in 1972 and described by Fox (1974) as Hesperornis
cf. regalis. He noted it was more similar to regalis than to crassipes
in being slender and lacking the metatarsal II tuberosity of crassipes,
though it is slightly larger. However, the lack of a rugosity is plesiomorphic
and the width / length ratio (4.47) resembles H. gracilis (4.45) more
than H. regalis (4.00-4.13). Nessov and Yarkov (1993) thought it possibly
belonged to "another more advanced species", and indeed it was referred
to Aotsuka and Sato's new species H. lumgairi by those authors.
References- Fox, 1974. A Middle Campanian, nonmarine occurrence of the
Cretaceous toothed bird Hesperornis Marsh. Canadian Journal of Earth
Sciences. 11(9), 1335-1338.
Nicholls, 1988. Marine vertebrates of the Pembina Member of the Pierre Shale
(Campanian, Upper Cretaceous) of Manitoba and their significance to the biogeography
of the Western Interior Seaway. PhD Thesis. University of Calgary. 317 pp.
Nessov and Yarkov, 1993. [Hesperornithes in Russia] Russkii Ornitolocheskii
Zhurnal. 2(1), 37-54.
Aotsuka, Hatcher, Janzic and Sato, 2012. Diversity of the Hesperornithiformes
(Aves) from the Upper Cretaceous Pierre Shale in Southern Manitoba, Canada.
Journal of Vertebrate Paleontology. Program and Abstracts 2012, 57.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
H. regalis Marsh, 1872a
Late Santonian-Early Campanian, Late Cretaceous
Spinaptychus sternbergi and Hesperornis Zones of the Smoky Hill
Chalk Member of the Niobrara Formation, Kansas, US
Holotype- (YPM 1200) third cervical vertebra (22.5 mm), sixth cervical vertebra
(29 mm), fourth dorsal vertebra (24 mm), fifth dorsal vertebra (24 mm), dorsal
ribs, third caudal vertebra (12 mm), fourth caudal vertebra (12 mm), fifth caudal
vertebra (13 mm), sixth caudal vertebra (13.5 mm), seventh caudal vertebra (13
mm), eighth caudal vertebra (15.2 mm), ninth caudal vertebra (16 mm), pygostyle
(25 mm), partial pelvis, femora (99.2, 99.1 mm), patellae (108.54 mm), tibiotarsi (321.11 mm), fibulae
(240 mm), tarsometatarsi (136.4, 135.9 mm), phalanx III-1 (40.24 mm), phalanx
III-2 (30 mm), proximal phalanx III-3, phalanx IV-1 (44.22 mm), phalanx IV-2 (39.5
mm), phalanx IV-3 (40 mm), proximal phalanx IV-4
Referred- (AMNH 2181) femur, patella, tibiotarsus, fibula (Bell and Chiappe, 2020)
(AMNH 5100) sixteen cervical vertebrae, six dorsal vertebrae, synsacrum, four
caudal vertebrae, scapulae, ilia, pubes, ischia, femora, patellae, tibiotarsi,
fibulae, phalanx I-1, pedal ungual I, tarsometatarsi, phalanges II-1, phalanges
II-2, phalanx III-1, phalanx III-2, phalanx III-3, pedal ungual III, phalanges
IV-1, phalanges IV-2, phalanges IV-3, phalanges IV-4, pedal ungual IV (Sternberg,
1917)
(FMNH PA206) (Chiappe, 1996)
(FMNH PA316) (Chiappe, 1996)
(FHSM VP-186) fifth dorsal vertebra, sixth dorsal vertebra, synsacrum, incomplete
ilium, proximal pubis (Everhart, 2011))
(FHSM VP-2069) cervical vertebrae, dorsal vertebrae, dorsal ribs, synsacrum, caudal
vertebrae, scapula, coracoids (53.88 mm), incomplete sternum, sternal ribs, humerus, ilium,
pubis, ischium, femora (93.87 mm), patella, tibiotarsi, fibula, tarsometatarsi, proximal
phalanx II-1, phalanx III-1, phalanx IV-1, phalanx IV-2, phalanx IV-3, phalanx
IV-4 (Everhart, 2011)
(FHSM VP-2293) seven dorsal vertebrae, two proximal dorsal ribs,
scapula, humerus, partial femur, patella, partial tibiotarsus (Bell and
Chiappe, 2020)
(HMN MB Av 106.1) incomplete tibiotarsus (Zinoviev, 2011)
....(HMN MB Av 106.3) incomplete femur (Zinoviev, 2011)
....(HMN MB Av 106.8) proximal fibula (Zinoviev, 2011)
(HMN MB Av 106.2) tarsometatarsus (Zinoviev, 2011)
(HMN MB Av 106.10) patella (Zinoviev, 2011)
(KUVP 2289) axial material, femoral fragment (Chinsamy, Martin and Dodson, 1998)
(KUVP 71012) skull, mandibles, axis, cervical vertebrae,
tarsometatarsus (128 mm), eleven pedal phalanges (Martin, 1987; Witmer
and Martin, 1987)
(KUVP 123108) distal femoral fragment (Chinsamy, Martin and Dodson, 1998)
(LACM 128317) maxilla (Witmer, 1990)
(UNSM 1212) fifteen presacral vertebrae, three dorsal ribs, uncinate processes,
pubis, femur, patella, tarsometatarsus, phalanx III-1 (Everhart, 2011))
(USNM 53) three vertebrae (USNM online)
(USNM 54) three vertebrae (USNM online)
(USNM 55) two vertebrae (USNM online)
(USNM 77) pelvis (USNM online)
(USNM 78) sternum (USNM online)
(USNM 4978) anterior skull, partial mandibles, eight cervical vertebrae, six
dorsal vertebrae, dorsal ribs, partial uncinate process, synsacrum, caudal vertebrae,
scapula, coracoid, clavicle, sternum, sternal ribs, ilium, pubis, ischium, femora,
tibiotarsi, tarsometatarsi, pedal phalanges (Lucas, 1903)
(USNM 6622) premaxilla (Bell and Chiappe, 2020)
(USNM 7276) partial mandible (USNM online)
(USNM 7277) partial mandible (USNM online)
(USNM 11640) vertebra, pelvis (USNM online)
(USNM 13580) cranial material, dorsal vertebrae, dorsal rib, synsacrum, femur, patella, tibiotarsus,
fibula, tarsometatarsus (Bryant, 1983)
(USNM 13581) femur, partial tibiotarsus, proximal tarsometatarsus, phalanx (USNM
online)
(USNM 13882) dorsal vertebra (USNM online)
(YPM 903) posterior mandible (Shufeldt, 1915b)
(YPM 1201) (adult) partial femur (Marsh, 1872b)
(YPM 1202) partial femur (Marsh, 1872b)
(YPM 1203) pedal phalanx III-1 (37.9 mm) (Marsh, 1872b)
(YPM 1204) (Marsh, 1872b)
(YPM 1205) distal tibiotarsus (Marsh, 1875)
(YPM 1206) skull (257 mm), mandible (257 mm), teeth, third cervical vertebra
(24 mm), fourth cervical vertebra (26 mm), fifth cervical vertebra (28 mm),
sixth cervical vertebra (31 mm), seventh cervical vertebra (32 mm), eighth cervical
vertebra (33 mm), ninth cervical vertebra (32.5 mm), tenth cervical vertebra
(32 mm), three cervicals ribs (37, 83 mm), fourth dorsal vertebra, sixth dorsal
vertebra (25.5 mm), six dorsal ribs (145, 172, 190, 209 mm), six uncinate processes
(25, 54, 52, 55, 50, 30 mm), synsacrum (320 mm- first sacral 21 mm), first caudal
vertebra (19 mm), second caudal vertebra (15 mm), scapula, coracoid (54 mm),
clavicle (78 mm), sternum (~200 mm), five incomplete sternal ribs (110 mm),
humerus (152 mm), ilium (380 mm), pubis (330 mm), ischium (260 mm), femur (96
mm), tarsometatarsus (132 mm), proximal phalanx II-1, phalanx IV-1 (42.5 mm),
phalanx IV-2 (40 mm), phalanx IV-3 (41 mm) (Marsh, 1875)
(YPM 1207) quadrate, occiput, axis (29 mm), third cervical vertebra (22
mm), fourth cervical vertebra (24 mm), fifth cervical vertebra (28 mm),
sixth cervical vertebra (30 mm), seventh cervical vertebra (32 mm),
eighth cervical vertebra (33 mm), ninth cervical vertebra (31 mm),
tenth cervical vertebra (30 mm), eleventh cervical vertebra (29 mm),
twelfth cervical vertebra (24 mm), thirteenth cervical vertebra (25
mm), fourteenth cervical vertebra (23 mm), fifteenth cervical vertebra
(22 mm), sixteenth cervical vertebra (18 mm), seventeenth cervical
vertebra (20 mm), first dorsal vertebra (22 mm), second dorsal vertebra
(24 mm), third dorsal vertebra (24.5 mm), fourth dorsal vertebra (25
mm), fifth dorsal vertebra (24.5 mm), sixth dorsal vertebra (24 mm),
partial synsacrum, coracoid (55 mm), partial clavicle, pelvis, femora
(98.5, 101 mm), patellae (98 mm), partial tibiotarsi, partial fibulae,
tarsometatarsi (one partial; 136 mm), two pedal phalanges (Marsh, 1880)
(YPM 1470) synsacrum, caudal vertebra (YPM online)
(YPM 1471) limb bone fragments (YPM online)
(YPM 1472) femoral fragments (Marsh, 1880)
(YPM 1476) fourteenth cervical vertebra (24 mm), fifteenth cervical
vertebra (22 mm), sixteenth cervical vertebra (18 mm), seventeenth
cervical vertebra (22 mm), first dorsal vertebra (25 mm), second dorsal
vertebra (26.5 mm), third dorsal vertebra (26 mm), fourth dorsal
vertebra (26 mm), fifth dorsal vertebra (26 mm), synsacrum, scapula
(135 mm), partial sternum, incomplete pelvis (ilium ~307.47 mm), femur
(105 mm), patella (100 mm), tibiotarsi (335, 325 mm), proximal fibula,
metatarsal I (20 mm), distal phalanx I-1, pedal ungual I (14 mm),
tarsometatarsi (136 mm), phalanx II-1 (42 mm), phalanx II-2 (41 mm),
pedal ungual II (15 mm), phalanx III-1 (38.7 mm) (Marsh, 1880)
(YPM 1477) fourteenth cervical vertebra (24 mm), fifteenth cervical vertebra
(22 mm), sixteenth cervical vertebra (19 mm), seventeenth cervical vertebra
(20 mm), first dorsal vertebra (22 mm), second dorsal vertebra (24 mm), fourth
dorsal vertebra (25 mm), fifth dorsal vertebra (26 mm), sixth dorsal vertebra
(25 mm), seventh dorsal vertebra (22 mm), rib fragments, synsacrum, partial coracoid, femora (97 mm), patella
(103 mm), tibiotarsi, proximal fibulae (Marsh, 1880)
(YPM 1491) (adult) femoral fragments, tibiotrarsus, tarsometatarsus (Chiappe, 1996)
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
South Dakota, US
(SDSM 25005) incomplete femur, tibiotarsus (315 mm), incomplete fibula (Martin
and Varner, 1992)
Early Campanian, Late Cretaceous
Gammon Ferruginous Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.09.03.13) tarsometatarsus (109.4 mm) (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.00.01.00) femur (90.8 mm) (Aotsuka and Sato, 2016)
(CFDC B.00.01.09) ten vertebrae, femora, tibiotarsus, tarsometatarsus (Aotsuka
and Sato, 2016)
(CFDC B.00.03.00) femur (93.8 mm) (Aotsuka and Sato, 2016)
(CFDC B.00.18.00) tarsometatarsus (Nicholls, 1988)
(CFDC B.00.20.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.22.00) tarsometatarsus (Nicholls, 1988)
(CFDC B.00.23.00; lost) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.24.00) tarsometatarsus (Nicholls, 1988)
(CFDC B.00.25.00) tarsometatarsus (Nicholls, 1988)
(CFDC B.00.55.00) femur (87.4 mm) (Aotsuka and Sato, 2016)
(CFDC B.03.01.05) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.03.06.18) femur, tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.05.03.23) tibiotarsus, tarsometatarsus (118.5 mm) (Aotsuka and Sato,
2016)
(CFDC B.07.01.04) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.07.03.23) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.75.01.06) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.75.03.06) four vertebrae, tarsometatarsi (one fragmentary) (Nicholls,
1988)
(CFDC B.77.04.07) three vertebrae, femur, tarsometatarsus (Aotsuka and Sato,
2016)
(CFDC B.77.05.07) femur (93 mm) (Aotsuka and Sato, 2016)
(CFDC B.78.03.08) patella, tibiotarsus, tarsometatarsus (Nicholls, 1988)
(CFDC B.82.15.17) tarsometatarsus (Nicholls, 1988)
(CFDC B.83.03.18) tarsometatarsus (Nicholls, 1988)
(CFDC B.83.04.18) fragmentary tarsometatarsus (Nicholls, 1988)
(CFDC B.84.04.18) tibiotarsi, tarsometatarsus (128.9 mm) (Nicholls, 1988)
(CFDC B.2010.01.04) femur (96.2 mm) (Aotsuka and Sato, 2016)
(CFDC B.2010.01.09) vertebra, femur (93.3 mm) , patella, tibiotarsus (Aotsuka
and Sato, 2016)
(CFDC B.2012.01.04) femur (93 mm) (Aotsuka and Sato, 2016)
(FMNH PA218) five vertebrae, tarsometatarsi (105.9, 106.1 mm) (Bardack, 1968)
(FMNH PA288) tarsometatarsus (113.4 mm) (Aotsuka and Sato, 2016)
(MM V-137) femur (Aotsuka and Sato, 2016)
(MM V-247A) femur (87.1 mm) (Aotsuka and Sato, 2016)
(MM coll.; lost) two tarsometatarsi (Aotsuka and Sato, 2016)
(ROM coll.; lost) vertebra, tarsometatarsus (Aotsuka and Sato, 2016)
Diagnosis- (after Marsh, 1875a, b) seventh through tenth caudal vertebrae
with extremely long and flattened transverse processes (unknown in other hesperornithids);
pygostyle extremely broad and flattened (unknown in other hesperornithids).
(after Marsh, 1876) four sternal rib articulations; deep posterolateral excavations
in sternum.
(after Marsh, 1877) radius, ulna and manus absent (unknown in other hesperornithids).
(after Lucas, 1903) fourteen sacral vertebrae (unknown in other hesperornithids;
also in Aves).
(after Witmer, 1990) medial pneumatic lacrimal fossa small and shallow (unknown
in other Hesperornis); articular lacks pneumaticity (unknown in other
Hesperornis; also in Patagopteryx).
(proposed) scapular expanded distally (unknown in other hesperornithines; also
in Songlingornis); humerus longer than scapula (unknown in other hesperornithines;
also in Gansus and Yanornis);
Other diagnoses- Marsh's (1872a) original paper only described a few
characters, which are either more broadly distributed among hesperornithines
(short femur, elongate tibiotarsus) or incorrect (unfused metatarsals).
Marsh's (1872b) later description mentions several features as being distinctive,
but these are either primitive (trochanteric crest less expanded anteroposteriorly
than in grebes; supratendinal groove absent; hypotarsal grooves absent) or found
in other hesperornithines (femur with compressed cross section; metatarsal IV
longest; trochlea IV enlarged; pedal digit IV with crescent and peg articulations
between phalanges).
Marsh (1875a, b) mentions several characters as being distinctive, though the
described proximal caudal morphology (short centra, moderate sized transverse
processes and tall neural spines) is primitive. The partially closed acetabulum
is present in some other hesperornithines as well.
In 1877, Marsh noted Hesperornis was also distinctive for having dentary
teeth placed in grooves (also in Parahesperornis), a sternum without
a keel (probably also in Baptornis), and a hindlimb with diving adaptations
(too vague, and found in other hesperornithines in any case).
Lucas (1903a) noted the femur was articulated so that it projected transversely,
which is also now known to be true in Parahesperornis.
Comments- The holotype was discovered in 1871, though another specimen
(YPM 1205) was discovered in 1870 but not recognized as such until Marsh (1875a,
b). Marsh (1872a) gave a very brief commentary on the holotype, to be followed
by a more detailed description in 1872b. Marsh (1875a, b) added details from
a more complete specimen with a skull (YPM 1206). Marsh (1880) monographed the
taxon, using the holotype, YPM 1206, 1207, 1476 and 1477. He misidentified the
predentary as a basihyal (Martin and Naples, 2008). Palatal elements have been
controversial- a structure was identified by Marsh (1880) as a vomer, Gingerich
(1973, 1976) as a palatine, and Elzanowski (1991) as an anterior pterygoid.
Another element was identified as a palatine by Marsh, a vomer by Gingerich,
and a composite maxilla and palatine fragment by Elzanowski. Witmer and Martin
(1987) identified elements as a paired vomer which Elzanowski identified as
palatines. Bock (1969) questioned whether Hesperornis was really toothed,
but their presence in its jaws is unambiguous. Although the YPM lists YPM 1201-1204
as paratypes, Marsh 1872a only mentions one specimen in his initial description.
These are probably the four specimens mentioned in Marsh 1872b. Note Gregory
(1951) incorrectly called YPM 1206 the type.
While Hesperornis specimens have generally been thought to be limited
to the Early Campanian Hesperornis Zone of the Smoky Hill Chalk, Everhart
(2011) showed that the holotype and several other specimens (FSHM 186, 349 and
2069, UNSM 1212, USNM 13581, and YPM 1202-1204) are actually from the earlier
Spinaptychus sternbergi Zone. As it is unclear from the literature and
online databases which specimens (if any) are actually from the Hesperornis
Zone, they are not distinguished in this material list. It's also possible that
other bird material listed on this site as being from the Hesperornis
Zone is actually from the Spinaptychus sternbergi Zone.
Several specimens from other formations have been referred to Hesperornis
regalis. Russell (1967) mentioned many specimens from the Smoking Hills
Formation of the Northwest Territories. Bardack (1968) referred several specimens
from Manitoba to H. regalis (FMNH PA216-219, MM V-532). Witmer (1990)
noted differences in some Manitoban material, but Aotsuka and Sato (2016) referred
FMNH PA218 to H. regalis, and FMNH PA216-217 and MM V-532 to H. sp..
Fox (1974) referred a tarsometatarsus from the Foremost Formation of Alberta
to Hesperornis cf. regalis, though this seems untrue based on its proportions.
References- Marsh, 1872a. Discovery of a remarkable fossil bird. American
Journal of Science, Series 3. 3(13), 56-57.
Marsh, 1872b. Preliminary description of Hesperornis regalis, with notices
of four other new species of Cretaceous birds. American Journal of Science,
3rd series. 3(17), 359-365.
Marsh, 1873. Fossil birds from the Cretaceous of North America. American Journal
of Science, Series 3. 5(27), 229-231.
Marsh. 1875a. On the Odontornithes, or birds with teeth. American Journal of
Science, Series 3. 10(59), 403-408.
Marsh, 1875b. Odontornithes, or birds with teeth. The American Naturalist. 9(12),
625-631.
Marsh, 1876. Notice of new Odontornithes. The American Journal of Science and
Arts. 11, 509-511.
Marsh, 1877. Characters of the Odontornithes, with notice of a new allied genus.
American Journal of Science. 14, 85-87.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Noack, 1880. Die Bedeutung des Hesperornis regalis f�r die Descendanzteorie.
Jahresber. Ver. Naturwiss. Braunschweig. 1, 89-96.
Marsh, 1883. Birds with teeth. 3rd Annual Report of the Secretary of the Interior.
3, 43-88.
Thompson, 1890. On the systematic position of Hesperornis. Studies from
the Museum of Zoology. 1(10), 15 pp.
Lucas, 1903a. A skeleton of Hesperornis. Smithsonian Miscellaneous Collections.
45, 95.
Lucas, 1903b. Notes on the osteology and relationships of the fossil birds of
the genera Hesperornis, Hargeria, Baptornis, and Diatryma.
Proceedings of the United States National Museum. 26, 545-556.
Brown, 1911. Notes on the restorations of the Cretaceous birds Hesperornis
and Baptornis. Annals of the New York Academy of Sciences. 20, 401.
Shufeldt, 1915a. The fossil remains of a species of Hesperornis found
in Montana. The Auk. 32(3), 290-284.
Shufeldt, 1915b. Fossil birds in the Marsh Collection of Yale University. Transactions
of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Shufeldt, 1915c. On a restoration of the base of the cranium of Hesperornis
regalis. Bulletins of American Paleontology. 5, 73-85.
Sternberg, 1917. Hunting Dinosaurs in the Badlands of the Red Deer River, Alberta,
Canada. Published by the author, San Diego, California. 261 pp.
Stolpe, 1935. Colymbus, Hesperornis, Podiceps: ein Vergleich
ihrer hinteren Extremit�t. Journal of Ornithology. 83(1), 115-128.
Lane, 1947. A survey of the fossil vertebrates of Kansas, Part IV, The Birds.
Kansas Academy of Science, Transactions. 49(4), 390-400.
Edinger, 1951. The brains of the Odontognathae. Evolution. 5(1), 6-24.
Gregory, 1951. Convergent evolution: The jaws of Hesperornis and the
mosasaurs. Evolution. 5, 345-354.
Gregory, 1952. The jaws of the Cretaceous toothed birds Ichthyornis and
Hesperornis. Condor. 54(2), 73-88.
Martin and Tate, 1966. A bird with teeth. Museum Notes, University of Nebraska
State Museum. 29, 1-2.
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Contributions to Paleobiology. 27, 23-34.
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Martin, Stewart and Whetstone, 1980. The origin of birds: structure of the tarsus
and teeth. The Auk. 97, 86-93.
Bryant, 1983. Hesperornis in Alaska. Paleobios. 40, 1-8.
Martin, 1983. The origin and early radiation of birds. in Bush and Clark (eds).
Perspectives in Ornithology. Cambridge University Press, Cambridge. 291-338.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Buhler, 1987. On the mobility of the upper jaw and the segments of the braincase
in the Mesozoic birds. in Mourer-Chauvire (ed). L'�volution des oiseaux
d'apr�s le t�moignage des fossiles. Docum. Lab. Geol. Fac. Sci.
Lyon. 99, 41-48.
Martin, 1987. The beginning of the modern avian radiation. in Mourer-Chauvire
(ed). L'�volution des oiseaux d'apr�s le t�moignage des
fossiles. Docum. Lab. Geol. Fac. Sci. Lyon. 99, 9-19.
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oiseaux d'apr�s le t�moignage des fossiles. Docum. Lab. Geol.
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B�hler, Martin and Witmer, 1988. Cranial kinesis in the Late Cretaceous
birds Hesperornis and Parahesperornis. The Auk. 105, 111-122.
Nicholls, 1988. Marine vertebrates of the Pembina Member of the Pierre Shale
(Campanian, Upper Cretaceous) of Manitoba and their significance to the biogeography
of the Western Interior Seaway. PhD Thesis. University of Calgary. 317 pp.
Witmer, 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological
Journal of the Linnaean Society of London. 100, 327-378.
Elzanowski, 1991. New observations on the skull of Hesperornis with reconstructions
of the bony palate and otic region. Postilla. 207, 20 pp.
Martin and Varner, 1992. The occurence of Hesperornis in the Late Cretaceous
Niobrara Formation of South Dakota. Proceedings of the South Dakota Academy
of Science. 71, 95-97.
Chiappe, 1996. Late Cretaceous birds of Southern South America: Anatomy and
systematics of Enantiornithes and Patagopteryx deferrariisi. In Arratia
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Geowissenschaftliche Abhandlungen (A). 30, 203-244.
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and the volant Ichthyornis from the Niobrara Chalk of western Kansas.
Cretaceous Research. 19(2), 225-233.
Everhart, 2000-2014. http://www.oceansofkansas.com/Hesperornis.html
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radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
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Naples and Martin, 2004. Mandibular kinesis in Hesperornis. Sixth International
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A comparison with modern diving birds. Geological Society of America Abstracts
with Programs. 37(7), 133.
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A comparison with extant diving birds. Journal of Vertebrate Paleontology. 26(3),
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7, 61-65.
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locality indicates an earlier stratigraphic occurrence. Transactions of the
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Zinoviev, 2011. Notes on the hindlimb myology and syndesmology of the Mesozoic toothed bird Hesperornis regalis (Aves: Hesperornithiformes). Journal of Systematic Palaeontology. 9(1), 65-84.
Wilson and Chin, 2014. Comparative osteohistology of Hesperornis
with reference to pygoscelid penguins: The effects of climate and
behaviour on avian bone microstructure. Royal Society Open Science.
1(3), 140245.
Zinoviev, 2015. Comparative anatomy of the intertarsal joint in extant and fossil
birds: Inferences for the locomotion of Hesperornis regalis (Hesperornithiformes)
and Emeus crassus (Dinornithiformes). Journal of Ornithology. 156(supp
1), 317-323.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
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extant birds and its relevance for inferring the behavior and habitat
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Thivichon-Prince, Viriot and Louchart, 2016. Synchrotron imaging of
dentition provides insights into the biology of Hesperornis and Ichthyornis, the "last" toothed birds. BMC Evolutionary Biology. 16:178.
Wilson, Chin and Cumbaa, 2016. A new hesperornithiform (Aves) specimen
from the Late Cretaceous Canadian High Arctic with comments on
high-latitude hesperornithiform diet. Canadian Journal of Earth
Sciences. 53(12), 1476-1483.
unnamed clade (Hesperornis bazhanovi + Hesperornis crassipes
+ Hesperornis rossicus)
Diagnosis (proposed) metatarsal II trochlea almost completely hidden
in anterior view (also in Pasquiaornis and Enaliornis? sedgwicki).
H. crassipes (Marsh, 1876)
Marsh, 1880
= Lestornis crassipes Marsh, 1876
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Holotype- (YPM 1474) partial skeleton including dentary fragment, anterior
angular, teeth, atlantal centrum, fourth cervical vertebra (24 mm), coracoid,
clavicle (~80 mm), sternum (196 mm), partial femur (103 mm), patella (109 mm),
tarsometatarsi (135 mm), phalanx II-1 (40.5 mm), phalanx III-1 (39 mm), phalanx
IV-1 (42 mm), phalanx IV-2 (38 mm)
Referred- ?(AMNH 5102) incomplete tarsometatarsus (Nessov and Yarkov,
1993)
Diagnosis- (after Marsh, 1876) shallow posterolateral excavation in sternum;
large proximolateral rugosity on metatarsal II.
(proposed) coracoid articulations on sternum widely separated (unknown in other
Hesperornis; also in Patagopteryx).
Other diagnoses- Marsh (1876) also noted the sternum had five rib articulations
as opposed to H. regalis' four, but this is primitive as Baptornis
and Ichthyornis also have five. The less excavated posterolateral sternal
margin has uncertain polarity, as Ichthyornis' is also shallow, whereas
Gansus' is very deep.
Contra Marsh (1880), the tarsometatarsus does not appear more robust than in
H. regalis.
Comments- Discovered in 1876, the specimen described that year by Marsh
as a new genus of hesperornithid. Marsh (1880) placed it in Hesperornis
without comment, provided illustrations and further measurements. The angular
is illustrated by Gregory (1952). The species was accepted as valid by Martin
(1984), but it desperately needs to be redescribed. The tarsometatarsus as illustrated
by Marsh is quite distinct in shape from other Hesperornis, but the taxon
clades within Hesperornis when included in phylogenetic analyses (Mortimer,
unpublished; Bell and Chiappe, 2016).
References- Marsh, 1876. Notice of new Odontornithes. The American Journal
of Science and Arts. 11, 509-511.
Marsh, 1880. Odontornithes: a monograph on the extinct toothed birds of North
America. United States Geological Exploration of the 40th Parallel. Washington,
DC: U.S. Government Printing Office. 201 pp.
Shufeldt, 1915a. The fossil remains of a species of Hesperornis found
in Montana. The Auk. 32(3), 290-284.
Gregory, 1952. The jaws of the Cretaceous toothed birds Ichthyornis and
Hesperornis. Condor. 54(2), 73-88.
Martin, 1984. A new hesperornithid and the relationships of the Mesozoic birds.
Kansas Academy of Science, Transactions. 87, 141-150.
Nessov and Yarkov, 1993. [Hesperornithes in Russia] Russkii Ornitolocheskii
Zhurnal. 2(1), 37-54.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
H. rossicus Nessov and Yarkov,
1993
Early Campanian, Late Cretaceous
Bellemnellocamax mamillatus zone, Rychkovo, Volgograd, Russia
Holotype- (VRM 26306/2) proximal tarsometatarsus (~173 mm)
Paratypes- (VRM 26306/2a) partial sixteenth cervical vertebra
(VRM 26306/26) pedal phalanx IV-3
(VRM 26306/3) distal tarsometatarsus
(VRM coll.) dorsal vertebral fragment
Referred- (ZIN PO 5099) (subadult) proximal tarsometatarsal fragment
(Nessov and Yarkov, 1993)
? posterior dorsal vertebra, proximal tarsometatarsus (Yarkov and Nessov, 2000)
Early Campanian, Late Cretaceous
Bellemnellocamax mamillatus zone, Ivo Klack, Sweden
Paratype- (RM PZ R398) proximal tarsometatarsus
Referred- ?(LO 9067t) distal tibiotarsus (Mourer-Chauvire, 1992)
(SGU 3442 Ve01) proximal tarsometatarsus (Rees and Lindgren, 2005)
?(SGU 3442 Ve02) fifth dorsal vertebra (32 mm) (Rees and Lindgren, 2005)
Early Campanian, Late Cretaceous
Rybushka Formation, Saratov, Russia
(ZIN PO 5463) distal tarsometatarsus (~167 mm) (Panteleev, Popov and Averianov,
2004)
(ZIN PO 5464) (subadult) incomplete tarsometatarsus (158.8 mm) (Panteleev, Popov
and Averianov, 2004)
Late Campanian, Late Cretaceous
Bereslavka, Vologograd, Russia
distal tarsometatarsal fragment (Yarkov and Nessov, 2000)
Mid Campanian, Late Cretaceous
Millwood Member of the Pierre Shale Group, Manitoba, Canada
?(CFDC B.2010.01.23) proximal tarsometatarsus (Aotsuka et al., 2012; described
by Aotsuka and Sato, 2016)
Diagnosis- (after Nessov and Yarkov, 1993) adult size with tarsometarsus
over 150 mm long (also in Canadaga).
(after Kurochkin, 2000) proximal end of tarsometatarsus over 160% wider than
deep.
(after Panteleev et al., 2004) tarsometatarsal trochlea IV over 250% as wide
as trochlea III in anterior view.
Other diagnoses- Kurochkin (2000) listed several diagnostic characters.
The proximal tarsometatarsal articular surface is not more diagonally oriented
than in H. crassipes or H. bairdi. The lateral edge of the lateral
cotyla does not extend proximally past the intercotylar eminance, contra Kurochkin.
He states the medial cotyla is located more distally than the lateral cotyla,
which may be the same character as Rees and Lindgren's (2005) "cotyla medialis
slopes distally in regard to the nearly horizontal plane formed by the cotyla
lateralis." However, it seems Rees and Lindgren mistook their proximal
metatarsus SGU 3442 Ve01 as a left element when it is in fact from the right
side. Perhaps Kurochkin made the same mistake with the holotype, as the lateral
condyle is more distally placed in all specimens, which is typical of hesperornithids.
Panteleev et al. (2004) noted the inner toes were reduced, and while it seems
trochlea IV was indeed enlarged compared to III, the size of II is uncertain
due to damage. The absence of a ginglymoid trochlea II and III is shared with
Hesperornis mengeli, while trochlea II is equally hidden behind metatarsal
III in H. bazhanovi and crassipes.
Rees and Limdgren (2005) listed a few additional diagnostic characters. They
state the cotyla have less curvature, but this seems untrue of lateral cotyla
at least, while the concavity of H. bazhanovi's medial cotyla does not
seem very different. The intercotylar eminence does not seem more pointed than
Hesperornis bazhanovi, H. chowi or H. bairdi.
Comments- This species was originally named H. rossica, but must
be emended to rossicus as Hesperornis is masculine (Kurochkin,
2000). The holotype was first reported by Nessov (in Mourer-Chauvire, 1991)
as "an advanced hesperornithiform." The two vertebral fragments and
pedal phalanx were referred to H. rossicus by Nessov and Yarkov (1993),
though Kurochkin and Rees and Lindgren (2005) felt this was problematic due
to the presence of ZIN PO 5099. ZIN PO 5099 was originally referred to Hesperornis
sp. by Nessov and Yarkov (1993), but determined to be a young specimen of H.
rossicus by Panteleev et al. (2004). Thus only H. rossicus is known
from that locality, which makes the referral of the vertebrae and phalanx more
probable. Yarkov and Nessov (2000) referred a tarsometatarsal fragment reworked
to Paleocene deposits at Bereslavka to Hesperornithidae indet., but Panteleev
et al. (2004) referred it to H. rossicus. Yarkov and Nessov also described
a proximal tarsometatarsus and dorsal vertebra as Hesperornis sp., which
is tentatively referred to H. rossicus here, as it is from the same locality.
Rees and Lindgren (1999, 2005) described a dorsal vertebra and partial tibiotarsus
as Hesperornis sp., but these are here provisionally referred to H.
rossicus due to the presence of only one known hesperornithid at that locality
and their large size. LO 9067t had been previously mentioned as a possible large
hesperornithine by Nessov (in Mourer-Chauvire, 1992).
References- Mourer-Chauvire, 1991. Society of Avian Paleontology and
Evolution Information Newsletter. 5.
Mourer-Chauvire, 1992. Society of Avian Paleontology and Evolution Information
Newsletter. 6.
Nessov, 1992. [Flightless birds of meridional Late Cretaceous sea straits of
North America, Scandinavia, Russia and Kazakhstan as indicators of features
of oceanic circulation.] Byulleten Moskovskogo Obshchestva Ispytatelet Prirody
Otdel Geologicheskii. 67, 78-83.
Nessov and Yarkov, 1993. [Hesperornithes in Russia] Russkii Ornitolocheskii
Zhurnal. 2(1), 37-54.
Rees and Lindgren, 1999. Early Campanian hesperornithiform birds from the Kristianstad
Basin, southern Sweden. in Hoch and Brantsen (eds). Secondary adaptation to
life in water. Abstracts. University of Copenhagen, Copenhagen. 53.
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Yarkov and Nessov, 2000. New remains of hesperornithiform birds Hesperornithiformes
from the Volgograd Reigion. Russkii Ornitolocheskii Zhurnal, Ekspress Vypusk.
94, 3-12. [in Russian]
Panteleev, Popov and Averianov, 2004. New record of Hesperornis rossicus
(Aves, Hesperornithiformes) in the Campanian of Saratov Province, Russia. Paleontological
Research. 8(2), 115-122.
Rees and Lindgren, 2005. Aquatic birds from the Upper Cretaceous (Lower Campanian)
of Sweden and the biology and distribution of hesperornithiforms. Palaeontology.
48(6), 1321-1329.
Aotsuka, Hatcher, Janzic and Sato, 2012. Diversity of the Hesperornithiformes
(Aves) from the Upper Cretaceous Pierre Shale in southern Manitoba, Canada.
Journal of Vertebrate Paleontology. Program and Abstracts 2012, 57.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
H. bazhanovi
(Nessov and Prizemlin, 1991) new combination
= Asiahesperornis bazhanovi Nessov and Prizemlin, 1991
Maastrichtian, Late Cretaceous
Zhuravlovskaya Svita (not Eginsaiskaya Svita), Kazakhstan
Holotype- (IZASK 5/287/86a) incomplete tarsometatarsus (~122 mm)
Paratypes- (IZASK 5/287/86) dorsal vertebra
(IZASK 5/287/86b) partial tarsometatarsus
(IZASK 5/287/86B) distal tibiotarsus
(IZASK 5/293/87) dorsal vertebra
Referred- (IZASK 1/KM 97) proximal tarsometatarsus (~120-125 mm) (Malakhov
and Ustinov, 1998)
(IZASK 2/KM 97) cervical vertebra (Malakhov and Ustinov, 1998)
(IZASK 3/KM 97) partial tarsometatarsus (~80-90 mm) (Malakhov and Ustinov, 1998)
(IZASK 5/KM 97) distal femur (~60-70 mm) (Malakhov and Ustinov, 1998)
(IZASK 22/KM 97) tooth (Malakhov and Ustinov, 1998)
(IZASK 218/B-2003) partial tibiotarsus (Dyke et al., 2006)
(IZASK 220/B-2003) partial tarsometatarsus (Dyke et al., 2006)
? two distal tibiotarsi, proximal tarsometatarsus (Nessov in Mourer-Chauvire,
1992)
Diagnosis- (after Nessov and Prizemlin, 1991) (?) medial tibiotarsal
condyle markedly compressed transversely; (?) anterior intercondylar groove
deep; (?) scar for the attachment of the first metatarsal is very small, located
proximally on the shaft.
(proposed) round fossa around distal vascular foramen between metatarsals III
and IV.
Other diagnoses- Kurochkin (2000) listed the characters from Nessov and
Prizemlin's (1991) diagnosis (which has not been translated from Russian) which
he considered were not generalized hesperornithine characters. The gracility
and parallel sides of the tarsometatarsus are plesiomorphies compared to Hesperornis
regalis. The sharp posterolateral tarsometatarsal crest is also present
in Hesperornis bairdi, while a sharp posteromedial crest is present in
H. bairdi, H? mengeli and Parahesperornis. A deep proximodorsal
metatarsal III fossa is also present in Hesperornis and Parahesperornis,
while those of H. regalis and H. chowi are equally narrow. The
high dorsolateral crest by this feature is not easily observable in the figures,
so cannot be compared to other taxa. Hesperornis chowi and Parahesperornis
also have an expanded fossa distally between metatarsals III and IV, though
they are not as round as in Asiahesperornis. Trochlea IV is larger compared
to III in Hesperornis crassipes, H? mengeli and H. rossicus than
in bazhanovi. The remaining characters listed above aren't possible to
see in the published figures, making comparison to other taxa and thus their
diagnostic status uncertain. However, compressed medial tibiotarsal condyles
and deep intercondylar grooves are present in most derived hesperornithines.
Dyke et al. (2006) listed a couple additional features in their diagnosis. Hesperornis
and Parahesperornis also have prominent medial and lateral grooves on
the dorsal tarsometatarsus between the metatarsals. Hesperornis regalis
and H. bairdi both have well developed grooves on the posterior surface
of their third trochlea.
Comments- The type material was first reported by Prizemlin and Nessov
(in Mourer-Chauvire, 1990) as "a large hesperornithiform bird of a new
genus, and maybe a new family." Nessov and Prizemlin (1991) later described
it as the new genus Asiahesperornis, which they placed in a new subfamily
Asiahesperornithinae. Yet comparisons suggest the species is more similar to
Hesperornis regalis than some other species assigned to that genus such
as H. gracilis, H. bairdi and H? mengeli, where is is resolved
in phylogenetic analyses (Mortimer, unpublished; Bell and Chiappe, 2016). Thus
it is placed within Hesperornis here, in a combination not seen in the
literature.
The stratigraphy of the Kushmurun Quarry where Asiahesperornis is found
has been controversial, with Dyke et al. (2006) assigning it to the Zhuravlovskaya
Svita, not the Eginsaiskaya Svita as found in Nessov in Mourer-Chauvire (1992)
and Kurochkin (2000). IZASK 5/287/86 was originally misidentified as a cervical
vertebra by Nessov and Prizemlin (1991), but reidentified by Kurochkin (2000).
This material is only provisionally referred to a single taxon of hesperornithine,
based on size. Nessov and Yarkov (1993) later illustrated IZASK 5/293/87 and
5/287/86B as merely "hesperornithiforms" and provisionally assigned
IZASK 5/287/86b to another species, but Dyke et al. found no reason to doubt
their assignment to Asiahesperornis.
Bell and Chiappe (2020) stated dentary IZASK 4/KM 97 "shows clear
alveoli for the teeth. As this is not the case among other
hesperornithiforms, and the Asiahesperornis
material consists entirely of unassociated elements, it is unlikely
this specimen belongs to a hesperornithiform bird" and reassigned it to
Aves incertae sedis.
References- Mourer-Chauvire, 1990. Society of Avian Paleontology and
Evolution Information Newsletter. 4.
Nessov and Prizemlin, 1991. A large advanced flightless marine bird of the order
Hesperornithiformes of the Late Senonian of Turgai Strait - the first finding
of the group in the USSR. USSR Academy of Sciences, Proceedings of the Zoological
Institute. 239, 85-107 (in Russian).
Mourer-Chauvire, 1992. Society of Avian Paleontology and Evolution Information
Newsletter. 6.
Nessov and Yarkov, 1993. [Hesperornithes in Russia] Russkii Ornitolocheskii
Zhurnal. 2(1), 37-54.
Malakhov and Ustinov, 1998. New findings of Upper Cretaceous toothed birds (Aves;
Hesperornithiformes) in northern Kazakhstan. Kazakh State University Yearbook,
Biological Series. 1998, 162-167 (in Russian).
Kurochkin, 2000. Mesozoic birds of Mongolia and the former USSR. in Benton,
Shishkin, Unwin and Kurochkin (eds.). The Age of Dinosaurs in Russia and Mongolia.
533-559.
Dyke, Malakhov and Chiappe, 2006. The hesperornithiform bird Asiahesperornis
from Kushmurun, Northern Kazakhstan. Journal of Vertebrate Paleontology. 26(3),
57A-58A.
Dyke, Malakhov and Chiappe, 2006. A re-analysis of the marine bird Asiahesperornis
from northern Kazakhstan. Cretaceous Research. 27(6), 947-953.
Bell and Chiappe, 2016 (online 2015). A species-level phylogeny of the Cretaceous Hesperornithiformes
(Aves: Ornithuromorpha): Implications for body size evolution amongst the earliest
diving birds. Journal of Systematic Palaeontology. 14(3), 239-251.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
H? sp. (Bryant, 1983)
Coniacian-Campanian, Late Cretaceous
Ignek Formation, Alaska, US
Material- (UCMP 103841) (subadult) partial third dorsal vertebra, partial
fourth dorsal vertebra, partial fifth dorsal vertebra
Comments- This specimen was discovered in 1962 and described by Bryant
(1983) as Hesperornis sp.. He found no differences between it and H.
regalis specimen USNM 13580, and thought differences from the H. regalis
holotype were due to age. However, other hesperornithines are difficult to compare,
so the generic assignment should be provisional.
Reference- Bryant, 1983. Hesperornis in Alaska. Paleobios. 40,
1-8.
H. sp. (Hills, Nicholls, N��ez-Betelu and McIntyre,
1999)
Early-Middle Campanian, Late Cretaceous
Kanguk Formation, Nunavut, Canada
Material- ?(CMN 40824) (Wilson and Chin, 2014)
(NUVF 286) (subadult) four teeth (5.0-6.2 mm), vertebral fragments, rib
fragments, ilia (one partial, one fragmentary), femora (91.8, 94.5 mm),
tibiotarsal fragments, few elements (uncollected) (Wilson, 2012;
Wilson, Chin and Cumbaa, 2016)
(TMP 1997.004.0001) distal tarsometatarsus (Hills, Nicholls, N��ez-Betelu and McIntyre,
1999)
Comments- CMN 40824 was found
in June 1988 and was listed by Wilson and Chin (2014) as one of the
"Arctic specimens identified as hesperornithiforms in museum
collections", but is currently identified as indet. in the collection
so is probably one of the specimens which "could not be confidently
attributed to Hesperornis or even Aviale."
TMP 1997.004.0001 was found in July 1992 and was referred to Hesperornis sp. by Hills et al. (1999).
NUVF 286 was found in 2003, initially described in Wilson's (2012)
thesis. The latter states "a few associated bones below the
specimen could not be collected because they were frozen in
permafrost." The thesis was later published as Wilson and Chin
(2014) for the histology and Wilson et al. (2016) for the anatomy,
where it is referred to cf. Hesperornis sp.. This is due to the uncertain status of Canadaga and controversial synonymy of Hesperornis species, but they do say it is more robust than Parahesperornis.
References- Hills, Nicholls, N��ez-Betelu and McIntyre,
1999. Hesperornis (Aves) from Ellesmere Island and palynological correlation
of known Canadian localities. Canadian Journal of Earth Sciences. 36(9), 1583-1588.
Wilson. 2012. Paleobiology of hesperornithiforms (Aves) from the
Campanian Western Interior Seaway of North America, with analyses of
extant penguin bone histology. PhD thesis, University of Colorado. 150
pp.
Wilson and Chin, 2014. Comparative osteohistology of Hesperornis
with reference to pygoscelid penguins: The effects of climate and
behaviour on avian bone microstructure. Royal Society Open Science.
1(3), 140245.
Wilson, Chin and Cumbaa, 2016. A new hesperornithiform (Aves) specimen
from the Late Cretaceous Canadian High Arctic with comments on
high-latitude hesperornithiform diet. Canadian Journal of Earth
Sciences. 53(12), 1476-1483.
H. cf. regalis (Russell, 1967)
Early Campanian, Late Cretaceous
Smoking Hills Formation, Northwest Territories, Canada
Material- (CMN 10431) (adult) tarsometatarsal fragment
(CMN 10432) (subadult) ?tibiotarsal fragment, tarsometatarsus
(CMN 10433) (subadult) tarsometatarsus
(CMN 10434A) (adult) first sacral vertebra (22.0 mm), fragmentary tibiotarsi
(CMN 10434B) (subadult) third dorsal vertebra (22.0 mm), fourth dorsal
vertebra (22.0 mm), fifth dorsal vertebra (21.5 mm), dorsal vertebra,
sacral fragments, pelvic fragments, femora, tibiotarsus, tarsometatarsus
(CMN 10437) (subadult) tarsometatarsal fragments
(CMN 10441) (adult) sternal fragments, sternal ribs, femur (48.0 mm trans dist), tibiotarsal shaft
(CMN 10442) (subadult) tarsometatarsal fragment
(CMN 10446) (adult) fifth dorsal vertebra (~32 mm)
(CMN 10551) (juvenile) preacetabular process
Comments- Russell (1967) referred remains found in 1965 to Hesperornis
regalis as "their morphology in no way distinguishes them from corresponding elements of Hesperornis regalis", but according to Martin and Lim these may
H. chowi instead. However, the "brown beds" of the Anderson
River are not from the same formation as H. chowi.
References- Russell, 1967. Cretaceous vertebrates from the Anderson River,
N.W.T. Canadian Journal of Earth Sciences. 4(1), 21-38.
Martin and Lim, 2002. New information on the hesperornithiform
radiation. In Zhou and Zhang (eds.). Proceedings of the 5th Symposium
of the Society of Avian Paleontology and Evolution. 165-174.
H. sp. (Hills, Nicholls, N��ez-Betelu and McIntyre,
1999)
Late Campanian-Early Maastrichtian, Late Cretaceous
Mason River Formation, Northwest Territories, Canada
Reference- Hills, Nicholls, N��ez-Betelu and McIntyre, 1999.
Hesperornis (Aves) from Ellesmere Island and palynological correlation
of known Canadian localities. Canadian Journal of Earth Sciences. 36(9), 1583-1588.
H? sp. (Wilson, 2012)
Late Cretaceous
Horton River, Northwest Terrotories, Canada
Material- (CMN 11409) element
(CMN 11421) element
(CMN 11441) element
Late Cretaceous
Eglinton Island, Northwest Terrotories, Canada
(CMN 40730) element
Late Cretaceous
Devon Island, Nunavut, Canada
(CMN 51580) element
(CMN 51585) element
Comments- These were collected
in 1966 (CMN 11409, 11421, 11441), 1972 (CMN 40730), July 20 1998 (CMN
51580) and July 25 1998 (CMN 51585), and are in the CMN catalog as Hesperornis sp. (CMN 11421, 11441, 40730, 51580) or cf. Hesperornis
(CMN 11409, 51585). Wilson (2012; published as Wilson and Chin,
2014) stated that for these (and CMN 40824 from the Kanguk Formation)
"microbial alteration obscured the microstructure of three of these
bones, and the other five specimens could not be confidently attributed
to Hesperornis or even
Aviale." They are among the specimens Wilson et al. (2016) are
referring to when they state "undescribed specimens attributed to
hesperornithiforms have also been collected from Eglinton Island and
Horton River (Northwest Territories), and are housed at the CMN."
References- Wilson. 2012. Paleobiology of hesperornithiforms (Aves) from the
Campanian Western Interior Seaway of North America, with analyses of
extant penguin bone histology. PhD thesis, University of Colorado. 150
pp.
Wilson and Chin, 2014. Comparative osteohistology of Hesperornis
with reference to pygoscelid penguins: The effects of climate and
behaviour on avian bone microstructure. Royal Society Open Science.
1(3), 140245.
Wilson, Chin and Cumbaa, 2016. A new hesperornithiform (Aves) specimen
from the Late Cretaceous Canadian High Arctic with comments on
high-latitude hesperornithiform diet. Canadian Journal of Earth
Sciences. 53(12), 1476-1483.
H. sp.
Late Campanian, Late Cretaceous
Foremost Formation, Alberta, Canada
Material- (UCMP 108074) tarsometatarsus (UCMP online)
H. sp. (Bardack, 1968)
Turonian-Santonian, Late Cretaceous
Boyne Member of the Vermillion River Formation, Manitoba, Canada
Material- (FMNH 219) braincase fragment, posterior mandible, seven incomplete
dorsal vertebrae, femora, partial tibiotarsus, tarsometatarsus
Comments- These were collected in 1965 and referred to H. regalis
by Bardack (1968). Witmer (1990) notes the postcranium is slightly more gracile
and that differences exist in middle ear morphology, making that assignment
uncertain. This is especially true with the recent description of other species
similar to H. regalis, such as H. chowi.
References- Bardack, 1968. Fossil vertebrates from the marine Cretaceous
of Manitoba. Canadian Journal of Earth Sciences. 5, 145-153.
Witmer, 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological
Journal of the Linnaean Society of London. 100, 327-378.
H. sp. nov. (Tanaka, Kobayashi, Kurihara, Kano and Fiorillo, 2014)
Early Campanian, Late Cretaceous
Gammon Ferruginous Member of Pierre Shale Group, Manitoba, Canada
Material- (V-2487) (adult) distal femur, patella, tibiotarsi, proximal
tarsometatarsus, distal tarsometatarsus, several pedal phalanges
Diagnosis- (after Tanaka et al., 2015) medially positioned foramen for
M. ambiens on patella; flat femur with strong lateral orientation of fibular
trochlea.
Comments- Tanaka et al. (2014) referred to an unnamed hesperornithid
from Manitoba with the specimen number V-2487 that emerged in Hesperornis
as here used, which was later detailed by Tanaka et al. (2015) but has yet to
be formally described.
References- Tanaka, Kobayashi, Kurihara, Kano and Fiorillo, 2014. Phylogenetic
position of a new hesperornithiform from the Upper Cretaceous of Hokkaido, Japan.
Journal of Vertebrate Paleontology. Program and Abstracts 2014, 239.
Tanaka, Tokaryk and Kobayashi, 2015. A new small hesperornithiform from the
Upper Cretaceous Pierre Shale of Manitoba. Journal of Vertebrate Paleontology.
Program and Abstracts 2015, 223.
H. sp. (Bardack, 1968)
Early Campanian, Late Cretaceous
Gammon Ferruginous Member of the Pierre Shale Group, Manitoba, Canada
Material- (CFDC B.2010.02.13) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.2011.02.13) femur (Aotsuka and Sato, 2016)
(CFDC B.2011.03.13) (2 individuals) two tarsometatarsi (Aotsuka and Sato, 2016)
(CFDC B.2011.05.13) tarsometatarsus (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Pembina Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.00.02.00; lost) femur (Aotsuka and Sato, 2016)
(CFDC B.00.02.15-1) vertebra, tibiotarsus, tarsometatarsus (Aotsuka and Sato,
2016)
(CFDC B.00.04.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.04.03) femur (Aotsuka and Sato, 2016)
(CFDC B.00.06.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.07.00; lost) femur (Aotsuka and Sato, 2016)
(CFDC B.00.08.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.09.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.10.05) femur (Aotsuka and Sato, 2016)
(CFDC B.00.11.05) femur (Aotsuka and Sato, 2016)
(CFDC B.00.13.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.12.05) femur (Aotsuka and Sato, 2016)
(CFDC B.00.14.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.15.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.16.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.19.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.21.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.26.00) femur, tarsometarsus (Aotsuka and Sato, 2016)
(CFDC B.00.28.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.29.00) femur (Aotsuka and Sato, 2016)
(CFDC B.00.30.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.31.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.32.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.34.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.36.00) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.42.00) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.00.56.00; lost) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.59.05; lost) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.00.61.05; lost) femur (Aotsuka and Sato, 2016)
(CFDC B.01.01.15) femur (Aotsuka and Sato, 2016)
(CFDC B.01.04.13) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.02.01.21) fibula, tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.03.01.24) femur (Aotsuka and Sato, 2016)
(CFDC B.03.03.05) femur (Aotsuka and Sato, 2016)
(CFDC B.06.03.03) femur (Aotsuka and Sato, 2016)
(CFDC B.06.04.23) femur (Aotsuka and Sato, 2016)
(CFDC B.07.02.15) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.09.01.30) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.72.01.01) femur (Aotsuka and Sato, 2016)
(CFDC B.73.02.05) vertebra, tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.76.03.06) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.76.04.06) femur (Aotsuka and Sato, 2016)
(CFDC B.77.01.06) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.77.02.09; lost) synsacrum, femur, tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.78.01.07) fragmentary femur (Aotsuka and Sato, 2016)
(CFDC B.79.02.12) femur (Aotsuka and Sato, 2016)
(CFDC B.79.03.13) (?)tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.79.08.13) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.00.14) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.01.15) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.03.15) femur (Aotsuka and Sato, 2016)
(CFDC B.80.04.14) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.06.14) femur (Aotsuka and Sato, 2016)
(CFDC B.80.07.14) femur (Aotsuka and Sato, 2016)
(CFDC B.80.10.16; lost) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.11.16) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.80.12.16) tibiotarsi (Aotsuka and Sato, 2016)
(CFDC B.81.01.16) tibiotarsi (Aotsuka and Sato, 2016)
(CFDC B.81.02.16) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.81.04.16) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.81.07.16) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.81.10.16) femora (Aotsuka and Sato, 2016)
(CFDC B.82.01.17) vertebra, ilium, tibiotarsi, tarsometatarsi (Aotsuka and Sato,
2016)
(CFDC B.82.03.17) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.82.06.03) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.82.10.17) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.82.11.17; lost) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.83.02-2.18) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.84.02.18) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.84.03.18) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.84.05.18) femur (Aotsuka and Sato, 2016)
(CFDC B.85.01.03) femur (Aotsuka and Sato, 2016)
(CFDC B.2010.04.13) femur (Aotsuka and Sato, 2016)
(CFDC B.2011.01.03) tibiotarsus (Aotsuka and Sato, 2016)
(FMNH PA216) femur, tibiotarsus (Bardack, 1968)
(FMNH PA217; lost) femur, tibiotarsus (Bardack, 1968)
(FMNH PA286) distal femur (Aotsuka and Sato, 2016)
(FMNH PA289) tibiotarsus (Aotsuka and Sato, 2016)
(FMNH PA291) vertebral fragment, femur (Aotsuka and Sato, 2016)
(FMNH PA292) tibiotarsus (Aotsuka and Sato, 2016)
(MM P-532; lost) femur (Bardack, 1968)
(MM V-247B) femur (Aotsuka and Sato, 2016)
(MM V-395) femur (Aotsuka and Sato, 2016)
(MM V-606A) femur (Aotsuka and Sato, 2016)
(MM V-606B) femur (Aotsuka and Sato, 2016)
(MM V-607) femur (Aotsuka and Sato, 2016)
(MM V-608) femur (Aotsuka and Sato, 2016)
(MM V-1629) vertebra, femur (Aotsuka and Sato, 2016)
(MM coll.; lost) seven tibiotarsi (Aotsuka and Sato, 2016)
(ROM coll.) six femora, four tibiotarsi (Aotsuka and Sato, 2016)
Mid Campanian, Late Cretaceous
Millwood Member of the Pierre Shale Group, Manitoba, Canada
(CFDC B.02.02.05) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.06.03.15) tibiotarsus (Aotsuka and Sato, 2016)
(CFDC B.08.05.23) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.81.03.16) femur (Aotsuka and Sato, 2016)
(CFDC B.2010.01.15) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.2010.01.30) tarsometatarsus (Aotsuka and Sato, 2016)
(CFDC B.2010.03.23) femur (Aotsuka and Sato, 2016)
(CFDC B.2011.01.23) femur (Aotsuka and Sato, 2016)
(CFDC B.2011.02.23) tarsometatarsus (Aotsuka and Sato, 2016)
Comments- Several specimens were referred to H. regalis by Bardack
(1968). Nicholls and Russell (1990) stated 170 specimens of Hesperornis
were known from the Pembina Member, which presumably included those listed above
whose CFDC catalog numbers indicate they were catalogued before this (the number
after the B). These were detailed by Aotsuka and Sato (2016), who assigned most
to Hesperornis sp..
References- Bardack, 1968. Fossil vertebrates from the marine Cretaceous
of Manitoba. Canadian Journal of Earth Sciences. 5, 145-153.
Nicholls and Russell, 1990. Paleobiogeography of the Cretaceous Western Interior
Seaway of North America: The vertebrate evidence. Palaeogeography, Palaeoclimatology,
Palaeoecology. 79, 149-169.
Aotsuka and Sato, 2016. Hesperornithiformes (Aves: Ornithurae) from the
Upper Cretaceous Pierre Shale, southern Manitoba, Canada. Cretaceous
Research. 63, 154-169.
H. sp. (Macdonald, 1951)
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, South Dakota, US
Material- partial skeletons
Comments- Nicholls and Russell (1990) listed sixty-five specimens of
Hesperornis from this formation, though some are probably the types of
H. bairdi, H. chowi, H. macdonaldi or H. mengeli.
Reference- Macdonald, 1951. The fossil Vertebrata of South Dakota. in
Guidebook, Fifth Field Conference, Society of Vertebrate Paleontology. 63-74.
Nicholls and Russell, 1990. Paleobiogeography of the Cretaceous Western Interior
Seaway of North America: the vertebrate evidence. Palaeogeography, Palaeoclimatology,
Palaeoecology. 79, 149-169.
H. sp. (Tokaryk, 1999)
Campanian-Maastrichtian, Late Cretaceous
Pierre Shale Group, Saskatchewan, Canada
Material- (Tokaryk, 1999)
Campanian-Maastrichtian, Late Cretaceous
Pierre Shale Group, South Dakota, US
Material- (UCMP 113168) femur, tibiotarsus, pedal phalanges (UCMP online)
(UCMP 113169) tarsometatarsus (UCMP online)
(UCMP 113170) vertebrae (UCMP online)
(UCMP 123257) vertebral fragments, patella, pedal phalanges (UCMP online)
(UCMP 123258) femur (UCMP online)
(UCMP 123259) incomplete skeleton (UCMP online)
(USNM 244158) femur (USNM online)
(USNM 244159) proximal tibiotarsus, distal tibiotarsus (USNM online)
(USNM 244160) femur (USNM online)
(USNM 244161) tarsometatarsus (USNM online)
(USNM 244163) femur (USNM online)
(YPM PU 17193) femur (88 mm), patella, tibiotarsus, fibula (200.2 mm) (Wilson, Chin and Cumbaa, 2016)
Comments- These may be H. bairdi, H. chowi, H? macdonaldi
or H? mengeli based on stratigraphy.
References- Tokaryk, 1999. The toothed bird Hesperornis sp. (Hesperornithiformes)
from the Pierre Shale (Late Cretaceous) of Saskatchewan. The Canadian Field-Naturalist.
113(4), 670-672.
Wilson, Chin and Cumbaa, 2016. A new hesperornithiform (Aves) specimen
from the Late Cretaceous Canadian High Arctic with comments on
high-latitude hesperornithiform diet. Canadian Journal of Earth
Sciences. 53(12), 1476-1483.
H? sp. (Hilton, 2003)
Campanian, Late Cretaceous
Chico Formation, California, US
Material- (SC-VBHE1) pedal phalanx
Reference- Hilton, 2003. Dinosaurs and Other Mesozoic Reptiles of California.
University of California Press. 312 pp.
H. sp. (UCMP online)
Late Cammpanian, Late Cretaceous
Judith River Formation, Montana, US
Material- (UCMP 128365) proximal tarsometatarsus (UCMP online)
(UCMP 128366) distal tarsometatarsus (UCMP online)
H? sp. (Hutchinson, 2001)
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, Montana, US
Material- (MOR 971) tarsometatarsus (MOR online)
(MOR 975) distal tarsometatarsus (MOR online)
(UCMP 130124) proximal femur (Hutchinson, 2001)
(UCMP 131164) femur (Hutchinson, 2001)
Comments- The UCMP specimens are referred to cf. Hesperornis by
Hutchinson (2001), while the MOR specimens are referred to Hesperornis
in the museum's collection. The stratigraphic position suggests comparison to
Potamornis, though without a description any identification must remain
uncertain.
Reference- Hutchinson, 2001. The evolution of femoral osteology and soft
tissues on the line to extant birds (Neornithes). Zoological Journal of the
Linnaean Society. 131, 169-197.
H. sp. (Case, 1978)
Late Campanian, Late Cretaceous
Teapot Sandstone Member of the Mesaverde Formation, Wyoming, US
Material- (YPM PU 22390) partial tarsometatarsus (Case, 1978)
(YPM PU 22406) sternal fragment, three femora, fragments (Case, 1978)
(YPM PU 22407) distal tibiotarsal fragment (Case, 1978)
(YPM PU 22408) distal tibiotarsal fragment (Case, 1978)
(YPM PU 22437) three vertebrae, synsacrum, two phalanges (Case, 1978)
(YPM PU 22438) distal metatarsal IV (Case, 1978)
(YPM PU 22443) vertebrae, limb elements including tibiotarsus (Houde, 1987)
(YPM PU 22948) frontal (YPM online)
(YPM PU 22949) articular (YPM online)
Comments- Houde (1987) reported on the histology of YPM PU 22443, calling
it Hesperornis sp..
References- Case, 1978. News from members; Eastern region; Jersey City.
Society of Vertebrate Paleontology. News Bulletin. 114, 16-17.
Houde, 1987. Histological evidence for the systematic position of Hesperornis
(Odontornithes: Hesperornithiformes). The Auk. 104(1), 125-129.
H. sp. (Martin and Tate, 1967)
Middle Campanian, Late Cretaceous
Sharon Springs Formation of the Pierre Shale Group, Nebraska, US
Material- partial skeleton
Comments- This was discovered in 1966, and may be H. bairdi, H.
chowi, H? macdonaldi or H? mengeli based on stratigraphy.
Reference- Martin and Tate, 1967. A Hesperornis from the Pierre
Shale. Nebraska Academy of Science Proceedings. 77th Annual Meeting. 40.
H. sp. (Shufeldt, 1915a)
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation,
Kansas, US
Material- (FSHM 349) specimen including pedal phalanx III-1 (37.2 mm)
(Everhart, 2011)
(USNM 244239) tarsometatarsus (USNM online)
(YPM 1475) (YPM online)
(YPM 1479) vertrbral fragments, sacral fragments (Chiappe, 2002)
(YPM 1480) proximal tibiotarsus, phalanx (Chiappe, 2002)
(YPM 1481) sacrum, femur, tibiotarsus, tarsometatarsus (Chiappe, 2002)
(YPM 1482) tibiotarsal fragment (YPM online)
(YPM 1483) vertebral fragments, synsacral fragments (YPM online)
(YPM 1484) synsacral fragments (YPM online)
(YPM 1485) vertebral fragment (YPM online)
(YPM 1486) proximal tarsometatarsal fragments (YPM online)
(YPM 1487) vertebral fragments, synsacral fragments (YPM online)
(YPM 1488) fragments (YPM online)
(YPM 1489) (adult) femur, tibiotarsus, fragments (Chiappe, 2002)
(YPM 1490) vertebral fragments, synsacrum (YPM online)
(YPM 1492) vertebral fragments (YPM online)
(YPM 1493) fragmentary synsacrum (YPM online)
(YPM 1494) fragments (YPM online)
(YPM 1495) vertebral fragment (YPM online)
(YPM 1496) synsacral fragment (YPM online)
(YPM 1497) skull, cervical vertebra(e), rib (YPM online)
(YPM 1498) phalanx (YPM online)
(YPM 1499) cervical vertebrae, dorsal vertebrae, femora, patellae, tibiotarsus, fibulae, tarsometatarsus, pedal phalanx III-1
(39.1 mm) (Shufeldt, 1915a)
Comments- Shufeldt (1915a) quoted Lull as saying YPM 1499 is either H.
regalis or H. sp. indet., and is more similar to H. montanus
than to H. regalis specimens YPM 1206, 1474 and 1477 in size, general
appearence and the shallowness of its lateral central fossae. These specimens
are listed by Chiappe (2002) and the YPM collections as being Hesperornis
sp., and may be H. regalis, H. gracilis, H. crassipes
or even Parahesperornis based on their locality.
References- Shufeldt, 1915a. The fossil remains of a species of Hesperornis
found in Montana. The Auk. 32(3), 290-284.
Chiappe, 2002. Basal bird phylogeny: Problems and solutions. In Chiappe and
Witmer (eds). Mesozoic birds: Above the heads of dinosaurs. Berkeley: University
of California Press. 448-472.
Everheart, 2011. Rediscovery of the Hesperornis regalis Marsh 1871 holotype
locality indicates an earlier stratigraphic occurrence. Transactions of the
Kansas Academy of Science. 114(1-2), 59-68.
Wilson and Chin, 2014. Comparative osteohistology of Hesperornis
with reference to pygoscelid penguins: The effects of climate and
behaviour on avian bone microstructure. Royal Society Open Science.
1(3), 140245.
H. sp. (Davis and Harris, 1997)
Middle-Late Campanian, Late Cretaceous
Ozan Formation, Arkansas, US
Material- (SAU 203) tibiotarsal fragment (Bell, Irwin and Davis, 2015)
(SAU 204) incomplete tarsometatarsus (~158 mm) (Davis and Harris, 1997)
pedal phalanx III-? (Bell, Irwin and Davis, 2015)
References- Davis and Harris, 1997. Discovery of fossil Cretaceous bird
in southwest Arkansas. Journal of the Arkansas Academy of Science. 51, 197-198.
Bell, Irwin and Davis, 2015. Hesperornithiform birds from the Late Cretaceous
(Campanian) of Arkansas, USA. Transactions of the Kansas Academy of Science.
118(3/4), 219-229.
H. sp. (Bell, Irwin and Davis, 2015)
Late Campanian, Late Cretaceous
Marlbrook Marl Formation, Arkansas, US
Material- pedal phalanx III-1 (45.5 mm) (Bell, Irwin and Davis, 2015)
Reference- (FHSM VP-17988) Bell, Irwin and Davis, 2015. Hesperornithiform
birds from the Late Cretaceous (Campanian) of Arkansas, USA. Transactions of
the Kansas Academy of Science. 118(3/4), 219-229.
H. sp. (Bell, Irwin and Davis, 2015)
Late Cretaceous
US
Material- (NHMUK A-720) partial pelvis (Bell and Chiappe, 2020)
(KUVP 2280) dorsal vertebra (Bell and Chiappe, 2020)
(SDSM 551) material including pedal phalanx III-1 (38 mm) (Bell, Irwin and Davis, 2015)
(SDSM 5312) cervical vertebrae, dorsal vertebrae, synsacrum, incomplete
pelvis, femur, patella, tibiotarsus, tarsometatarsus, phalanx III- 1
(42.3 mm), three pedal phalanges (Bell, Irwin and Davis, 2015)
(SDSM 5860) pelvis (Bell and Chiappe, 2020)
(UNSM 4-19-5-36) third dorsal vertebra, pelvic material (Bell and Chiappe, 2020)
(UNSM 10148) cranial material (Bell and Chiappe, 2020)
References- Bell, Irwin and Davis, 2015. Hesperornithiform birds from
the Late Cretaceous (Campanian) of Arkansas, USA. Transactions of the Kansas
Academy of Science. 118(3/4), 219-229.
Bell and Chiappe, 2020. Anatomy of Parahesperornis: Evolutionary mosaicism in the Cretaceous Hesperornithiformes (Aves). Life. 10(5), 62.
H. sp. nov. aff. regalis. (Kurochkin, 2004)
Early Campanian, Late Cretaceous
Rybushka Formation, Saratov, Russia
Material- (PIN 5027/5) proximal tarsometatarsus (40.6 mm trans) (Kurochkin, 2004; described in Zelenkov, Panteleyev and Yarkov, 2017)
(ZIN PO 6610) distal tarsometatarsus (Zelenkov, Panteleyev and Yarkov, 2017)
(ZIN PO 6611) distal tibiotarsus (35.1 mm trans) (Zelenkov, Panteleyev and Yarkov, 2017)
Early Campanian, Late Cretaceous
Bellemnellocamax mamillatus zone, Rychkovo, Volgograd, Russia
(PIN 5027/6) proximal tarsometatarsus (Zelenkov, Panteleyev and Yarkov, 2017)
Comments- Kurochkin (2004) stated PIN 5027/5 differs from the contemporary
H. rossicus "by inverse ratio of the articular cotylas and some
other characters", and that it also differs from H. regalis, H. crassipes,
H. gracilis and H. bairdi, so is a new species. Zelenkov and Kurochkin (2015) referred it to H. rossicus without comment, but Zelenkov et al. (2017) listed several differences from H. rossicus that resembled H. regalis instead. They stated "the only essential difference of the specimen described here from H. regalis
is the absence in proximal view of a distinct incisure in the dorsal
margin of the bone medial to the eminentia intercotylaris (this
incisure is also absent in H. rossicus, H. mengeli, H. lumgairi, and Asiahesperornis bazhanovi)." Zelenkov et al. list several characters distinguishing distal tarsometatarsus ZIN PO 6610 from H. regalis. These two specimens plus tibiotarsus ZIN PO 6611 and tarsometatarsus PIN 5027/6 are called Hesperornis sp. 1 by Zelenkov et al..
References- Kurochkin, 2004. New fossil birds from the Cretaceous of Russia.
Sixth International Meeting of the Society of Avian Paleontology and Evolution,
Abstracts. 35-36.
Zelenkov and Kurochkin, 2015. Class Aves. In Kurochkin, Lopatin and
Zelenkov (eds.). Fossil vertebrates of Russia and adjacent countries.
Part 3. Fossil Reptiles and Birds. GEOS. 86-290.
Zelenkov, Panteleyev and Yarkov, 2017. New finds of hesperornithids in
the European Russia, with comments on the systematics of Eurasian
Hesperornithidae. Paleontological Journal. 51(5), 547-555.
H. sp. nov. aff. rossicus. (Zelenkov, Panteleyev and Yarkov, 2017)
Early Campanian, Late Cretaceous
Rybushka Formation, Saratov, Russia
Material- (ZIN PO 6609) distal tarsometatarsus
Comments- Zelenkov et al.
(2017) stated this can be "distinguished from specimen ZIN, no. PO 6610
by the considerably smaller size" and "the very poorly developed fovea
lig. collateralis on the lateral surface of trochlea metatarsi
IV." They believe the "specimen likely belongs to a separate Hesperornis species" and that the "narrow trochlea metatarsi IV with a deep and narrow sulcus suggests that this form is close to H. rossicus rather than to H. regalis." Zelenkov et al. call this Hesperornis sp. 2.
Reference- Zelenkov, Panteleyev and Yarkov, 2017. New finds of hesperornithids in
the European Russia, with comments on the systematics of Eurasian
Hesperornithidae. Paleontological Journal. 51(5), 547-555.
H. sp. nov. aff. bazhanovi (Zelenkov, Panteleyev and Yarkov, 2017)
Late Campanian, Late Cretaceous
Bereslavka, Vologograd, Russia
Material- (PIN 5555/1) proximal tarsometatarsus (~34.8 mm trans)
(PIN 5555/2) proximal tarsometatarsus
(PIN 5555/3) distal tarsometatarsus
Comments- Zelenkov et al. (2017) state "in specimen PIN, no.
5555/2, the sulcus on the dorsal surface of the bone is considerably
more strongly developed than in other specimens; this is typical for
the genus Asiahesperornis (Dyke et al., 2006). This suggests that Hesperornis from Bereslavka is closer to A. bazhanovi, which is also similar is absolute size. However, specimen PIN, no. 5555/1 differs from A. bazhanovi
in the strongly oblique dorsomedial margin of the cotyla medialis,
which does not project dorsally. The morphological distinctions of the
Bereslavka form from A. bazhanovi suggest that it belongs to a separate taxon." They call this Asiahesperornis sp..
Reference- Zelenkov, Panteleyev and Yarkov, 2017. New finds of hesperornithids in
the European Russia, with comments on the systematics of Eurasian
Hesperornithidae. Paleontological Journal. 51(5), 547-555.
H? sp. (Yarkov and Nessov, 2000)
Late Campanian, Late Cretaceous
Bereslavka, Vologograd, Russia
Material- mid dorsal centrum, posterior dorsal centrum, pedal phalanx
IV-?
Comments- Yarkov and Nessov (2000) referred two dorsal centra and a pedal
phalanx to Hesperornithidae indet.
Reference- Yarkov and Nessov, 2000. New remains of hesperornithiform
birds Hesperornithiformes from the Volgograd Reigion. Russkii Ornitolocheskii
Zhurnal, Ekspress Vypusk. 94, 3-12. [in Russian]
Carinatae Merrem, 1813
Definition- (Passer domesticus <- Hesperornis regalis)
(modified from Cracraft, 1986)
Other definitions- (Ichthyornis dispar + Passer domesticus)
(Sereno, online 2005; modified from Chiappe, 1995)
(keeled sternum homologous with Vultur gryphus) (Gauthier and de Queiroz,
2001)
References- Cracraft, 1986. The origin and early diversification of birds. Paleobiology.
12, 383-399.
Chiappe, 1995. The first 85 million years of avian evolution. Nature. 378, 349-355.
Gauthier and de Quieroz, 2001. Feathered dinosaurs, flying dinosaurs, crown
dinosaurs, and the name "Aves." In Gauthier and Gall (eds.). New Perspectives
on the Origin and Early Evolution of Birds: Proceedings of the International
Symposium in Honor of John H. Ostrom. Peabody Museum of Natural History. 7-41.
Sereno, online 2005. Stem Archosauria - TaxonSearch. http://www.taxonsearch.org/dev/file_home.php
[version 1.0, 2005 November 7]
