incertae sedis

Apatornithiformes Martin, 1991
Apatornithidae Furbringer, 1888
Apatornis Marsh, 1873b
Definition- (Apatornis celer <- Ichthyornis dispar, Struthio camelus, Tetrao major, Vultur gryphus) (modified from Clarke, 2004)
= Iaceornis sensu Clarke, 2004
Definition- (YPM 1451 <- Ichthyornis dispar, Struthio camelus, Tetrao major, Vultur gryphus)
Comments- Clarke (2004) accidentally defined Iaceornis identically to Apatornis.
Brodkorb (1963) referred Cimolopteryx retusus to Apatornis, but transferred it to a new genus Palintropus in 1970.
References- Marsh, 1873b. On a new sub-class of fossil birds (Odontornithes). American Journal of Science, 3rd series. 5, 161-162.
Furbringer, 1888. Untersuchungeb zur Morphologie und Systematik der Vogel. Amsterdam: Holkema, 1751 pp.
Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. In Sibley, Hickey and Hickey (eds). Proceedings of the XIII International Ornithological Congress. 55-70.
Brodkorb, 1970. The generic position of a Cretaceous bird. Quarterly Journal of the Florida Academy of Science. 32(3), 239-240.
Martin, 1991. Mesozoic birds and the origin of birds. in Schultze and Trueb (eds). Origins of the Higher Groups of Tetrapods: Controversy and Consensus. 485-540.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History. 286: 1-179.
A. celer (Marsh, 1873a) Marsh, 1873b
Definition- (the species that includes YPM 1451) (Clarke, 2004)
= Ichthyornis celer Marsh, 1873a
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation, Kansas, US
Holotype- (YPM 1451) posterior synsacrum
Other diagnoses- Marsh (1873a) originally diagnosed Ichthyornis celer by contrasting it to Ichthyornis dispar. He stated it was larger, but this doesn't seem to be the case and he changed his mind by 1875. Marsh also stated the synsacrum was more slender than I. dispar, with a more concave posterior articular surface, but Clarke (2004) noted these differences don't seem to exist. Shufeldt (1915) noted the slender appearence was due to transverse crushing and a broken ventral edge.
Marsh (1880) later proposed additional differences from Ichthyornis. The synsacrum must contain at least one additional vertebra than the ten seen in the I. dispar holotype, but a specimen referred to I. victor (YPM 1732) has twelve vertebrae, and Aves basally have more vertebrae than the I. dispar holotype too. The presence of four mid sacral vertebrae with dorsally directed transverse processes (as opposed to Ichthyornis' three) is also seen in most Aves. Finally, Apatornis differs in lacking ossified tendons on its sacral vertebrae, but this is a plesiomorphy shared by almost all non-avian theropods.
Comments- The holotype was discovered in 1872 and described by Marsh (1873a) as a new species of Ichthyornis. He placed it in a new genus later that year without justification and described it in more detail in 1880. The partial skeleton YPM 1734 was referred to Apatornis by Marsh (1880), and most opinions on this taxon since 1880 have been based on this skeleton instead of the holotype synsacrum. Shufeldt (1915) believed the holotype belonged to a species of Ichthyornis, though without listed evidence. Howard (1955) thought the transversely narrow synsacrum which was unfused to the pelvis was similar to Telmabates (now recognized as a presbyornithid anatiform), but the sacrum is crushed transversely and the lack of fusion is primitive and also found in most Mesozoic euornithines, charadriiforms and other taxa. Martin (1987) described cervical and humeral characters of Apatornis, but these elements are not preserved in the holotype or YPM 1734. Elzanowski (1995) and Hope (2002) noted the problem that YPM 1734 was not comparable with the type, which was solved when Clarke (2002, 2004) separated the skeleton as the new taxon Iaceornis marshi. Clarke found Apatornis to be more derived than Ichthyornis based on the presence of four or more sacrals with dorsally directed transverse processes, but less derived than Aves due to the presence of thirteen or less sacrals. However, a similarly low number of sacral vertebrae is present in many avians, including many procellariiforms, charadriiforms and most of the 'higher land birds'. As Clarke did not include any neoavians in her analysis, it seems possible Apatornis could belong to that clade.
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.
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.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Howard, 1955. A new wading bird from the Eocene of Patagonia. American Museum Novitates. 1710, 25 pp.
Martin, 1987. The beginning of the modern avian radiation. Documents des Laboratoires de Geologie de la Faculte des Sciences de Lyon. 99, 9-20.
Elzanowski, 1995. Cretaceous birds and avian phylogeny. Courier Forschungsinstitut Senckenberg. 181, 37-53.
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.
Clarke, 2000. Ichthyornis and Apatornis reappraised. Vertebrata PalAsiatica. 38(suppl.), 9.
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. University of California Press. 339-388.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History. 286: 1-179.

Gallornis Lambrecht, 1931
G. straeleni Lambrecht, 1931
Berriasian-Hauterivian, Early Cretaceous
Auxerre, France
Holotype- (Royal Belgian Institute of Natural Sciences coll.) proximal humeral fragment, proximal femur
Comments- Lambrecht (1931) originally considered this taxon to be an anseriform intermediate between Anas and Cygnus in morphology. Hope (2002) considers this an avian based on the presence of an elevated trochanteric crest and an anteroposteriorly expanded antitrochanteric facet.
References- Lambrecht, 1931. Gallornis straeleni n. g. n. sp., ein Kreidevogel aus Frankreich. Bulletin de Musee Royal d'Histoire Naturelle de Belgique. 7, 1-6.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Jiuquanornis Wang, O'Connor, Li and You, 2013
J. niui Wang, O'Connor, Li and You, 2013
Early Aptian, Early Cretaceous
Xiagou Formation, Gansu, China
Holotype- (GSGM-05-CM-021) furcula, sternum (28.9 mm), sternal ribs
Diagnosis- (after Wang et al., 2013) U-shaped furcula without hypocleidium; short, imperforate body of sternum; small lateral processes on sternum; lateral trabeculae distally expanded medially; elongate intermediate trabeculae, equal to lateral trabeculae in distal extent; V-shaped xiphoid formed by short, fused medial trabeculae.
Comments- This specimen was mentioned by Atterholt et al. (2010), first described by You et al. (2010), then redescribed and named by Wang et al. (2013). The latter both used versions of O'Connor's analysis to recover it more derived than Archaeorhynchus and Patagopteryx, but less than Carinatae sensu Chiappe.
References- Atterholt, O'Connor, Harris, Li and You, 2010. Avian taxonomic diversity and anatomical disparity in the Lower Cretaceous Xiagou Formation of the Changma Basin, Gansui Province, People's Republic of China. Journal of Vertebrate Paleontology. Program and Abstracts 2010, 55A-56A.
You, Atterholt, O'Connor, Harris, Lamanna and Li, 2010. A second Cretaceous ornithuromorph bird from the Changma Basin, Gansu Province, Northwestern China. Acta Palaeontologica Polonica. 55, 617-625.
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.

Laornithoidea Cracraft, 1973
Laornithidae Cracraft, 1973
Comments- Cracraft (1973) created this monotypic family and superfamily for Laornis in his study of Grues, believing it to be related to rallids.
Reference- Cracraft, 1973. Systematics and evolution of the Gruiformes (class Aves). 3, Phylogeny of the suborder Grues. Bulletin of the American Museum of Natural History. 151, 128 pp.
Laornis Marsh, 1870
L. edvardsianus Marsh, 1870
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (YPM 820) distal tibiotarsus (22.6 mm wide)
Comments- Marsh (1870) felt Laornis showed strong resemblences to anseriforms, procellariiforms and larines. Shufeldt (1915) believed it was a generalized wader, comparing it to turkeys, swans and cranes. Cracraft (1973) redescribed it and assigned it to the Ralli in Gruiformes. Olson (1974) assigned it to Lari, but Olson and Parris (1987) later placed it in the invalid charadriiform family Graculavidae. They felt it was quite similar to Presbyornis, but resembled Palaeotringa in having a large M. peroneus brevis foramen in the anterolateral tibiotarsus. Brodkorb (1978) tentatively suggested affinities to Pelecaniformes.
References- Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary Formations of the United States. American Journal of Science, Series 2. 49, 205-217.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Cracraft, 1973. Systematics and evolution of the Gruiformes (class Aves). 3, Phylogeny of the suborder Grues. Bulletin of the American Museum of Natural History. 151, 128 pp.
Olson, 1974. Joel Cracraft. Systematics and evolution of the Gruiformes (Class Aves), 3: Phylogeny of the suborder Grues. Auk. 91(4), 862-865.
Brodkorb, 1978. Catalogue of Fossil Birds, Part 5 (Passeriformes). Bulletin of the Florida State Museum, Biological Sciences. 23(3), 140-228.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.

"Lonchodytes" pterygius Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53961) distal carpometacarpus
Comments- Brodkorb (1963) initially described pterygius in his new genus Lonchodytes, interpreted as a new family of gaviifiorm. It shares no elements with the type species, L. estesi, and was only referred to the genus based on both species being contemporaneous and supposedly resembling loons. Similarly, it was only diagnosed relative to Gavia and separated from L. estesi based on its smaller size. Olson and Feduccia (1980) considered it indeterminate, and Cracraft (1982) thought it didn't have much phylogenetic information. Most recently, Hope (2002) believed it was indeterminate and not a gaviiform, but that its phalangeal facets resemble larine charadriiforms.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Olson and Feduccia, 1980. Relationships and evolution of flamingos (Aves: Phoenicopteridae). Smithsonian Contributions to Zoology. 316, 73 pp.
Cracraft, 1982. Phylogenetic relationships and monophyly of loons, grebes, and hesperornithiform birds, with comments on the early history of birds. Systematic Zoology. 31(1), 35-56.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Palaeotringinae Wetmore, 1940
Reference- Wetmore, 1940. A systematic classification for the birds of the world. Smithsonian Miscellaneous Collections. 99(7), 1-11.
Palaeotringa Marsh, 1870
Comments- Marsh (1870) placed this genus in the Grallae. Previously assigned to the Gruiformes, then assigned to the invalid family Graculavidae by Olson and Parris (1987).
References- Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary Formations of the United States. American Journal of Science, Series 2. 49, 205-217.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
P. littoralis Marsh, 1870
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (YPM 830) distal tibiotarsus
Referred- ?(NJSM 11303) distal humerus (Olson and Parris, 1987)
References- Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary Formations of the United States. American Journal of Science, Series 2. 49, 205-217.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
P. vagans Marsh, 1872
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (YPM 835) distal tibiotarsus
References- Marsh, 1872. Preliminary description of Hesperornis regalis with notices of four other new species of Cretaceous birds. American Journal of Science, Series 3. 3, 360-365.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.

“Palaeotringa” vetus Marsh 1870
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
basal Hornerstown Formation, New Jersey
Holotype- (ANSP 13361) distal tibiotarsus
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Referred- (AMNH 25221) distal tibiotarsus (Hope, 2002)
Comments- Morton (1834) referred the holotype to Scolopax, though it was later named by Marsh (1870) and placed tentatively in his new genus Palaeotringa. Olson and Parris (1987) removed this from Palaeotringa and synonymized it with Telmatornis priscus, but Hope (2002) noted it differs from charadriiforms in several characters. She found gruids were most similar, along with idiornithids and Telmabates (a presbyornithid). A partial tibiotarsus (YPM 2808) was referred to P. vetus by Halsey (1955), but as this is from the Eocene, it is unlikely to belong to this species.
References- Morton, 1934. Synopsis of the Organic Remains of the Cretaceous of the US. Philadelphia: Key and Biddle. 96 pp.
Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary Formations of the United States. American Journal of Science, Series 2. 49, 205-217.
Halsey, 1955. A check-list of the Cretaceous and Tertiary vertebrates of New Jersey. Journal of Paleontology. 29, 903-914.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Volgavis Nessov and Jarkov, 1989
V. marina Nessov and Jarkov, 1989
Late Maastrichtian, Late Cretaceous
Malaja Ivanovka, Russia
Holotype- (ZIN PO 3638) incomplete mandibles
Comments- Considered a possible charadriiform by Nessov and Jarkov (1989) and Hope (2002), the latter noted the decurved symphysis resembles fregatids and stercorariids. Such a feature is probably prone to convergence among seabirds, thus Volgavis' relationships remain uncertain.
References- Nessov and Jarkov, 1989. New Cretaceous-Paleogene birds of the USSR and some remarks on the origin and evolution of the class Aves. Proceedings of the Zoological Institute, Leningrad. 197, 78-97.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Cimolopterygidae Brodkorb, 1963
Comments- While largely ignored since Brodkorb created it, this family was reinstated by Agnolín (2010) for Cimolopteryx, Ceramornis and Lamarqueavis. However, Mohr et al. (2021) critique his proposed characters. They correctly note the distally extended procoracoid process and distally placed supracoracoid foramen are only present in Lamarqueavis and the Irvine bird. Additionally, the laterally angled glenoid is only present in Cimolopteryx rara and Lamarqueavis assuming Longrich et al.'s (2011) photos are taken orthogonally, and the supracoracoid foramen is only enlarged in the Irvine bird. Mohr et al. concluded "both the monophyly of Cimolopterygidae and its inclusion within Charadriiformes lack discrete character support. Cimolopterygidae is most parsimoniously considered a provisional taxon of non-neornithine ornithurine birds that possess similar coracoids and may be closely related." They included Cimolopteryx rara, "C." maxima, "C." minima, "C." petra, Ceramornis, Lancian Ornithurine A, Lancian Ornithurine C (here assigned to the presbyornithid "Styginetta lofgreni"), the Steveville bird, the Onefour bird and their new Ornithurine G. As Longrich et al. recovered these in a polytomy with Crypturellus, Iaceornis, Gallus and Anas, cimolopterygid-grade taxa are here placed in Aves although they may end up being non-avian carinates.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
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.
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.

Cimolopteryx Marsh, 1892
= “Cimolopteryx” Marsh, 1889
Other diagnoses- Hope (2002) proposed several characters as being diagnostic for the genus- coracoid robust; neck of the coracoid stout and subtriangular in cross section; scapular cotyla of the coracoid slightly elongated transverse to the long axis of the coracoid; lateral process of the coracoid small. However, Longrich et al. (2011) wrote "the coracoids of these birds are not particularly robust; the subtriangular neck of the scapula is found in a range of birds, e.g. Enantiornis and Gallus, the scapular facet is subequal in anteroposterior and transverse dimensions in C. rara, and the lateral process is not preserved on any specimen except for the holotype of C. rara."
References- Marsh, 1889. Discovery of Cretaceous Mammalia. American Journal of Science. 38, 83.
Marsh, 1892. Notes on Mesozoic vertebrate fossils. American Journal of Science. 44, 170-176.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
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.
C. rara Marsh, 1892 (emmended by Sharpe, 1899)
= “Cimolopteryx rarus” Marsh, 1889
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (YPM 1805) coracoid
Diagnosis- (after Longrich et al., 2011) slender, dorsoventrally compressed coracoid shaft; weakly triangular scapular cotyle, weak medial excavation of acrocoracoid; prominent buttress inside triosseal canal and below scapular cotyle; coracoid with lateral process.
Comments- Cimolopteryx was first mentioned in a footnote by Marsh (1889) before being officially described in 1892. Brodkorb (1963) referred distal carpometacarpus UCMP 53964 to C. rara, but it was later identified by Stidham (2001) as an unnamed species of his new presbyornithid genus.
References- Marsh, 1889. Discovery of Cretaceous Mammalia. American Journal of Science. 38, 83.
Marsh, 1892. Notes on Mesozoic vertebrate fossils. American Journal of Science. 44, 170-176.
Sharpe, 1899. A hand-list of the genera and species of birds. Vol. 1. British Museum (Natural History). 303 pp.
Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Stidham, 2001. The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes). PhD Thesis, University of California. 257 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. 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.
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.

"Cimolopteryx" maxima Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53973) proximal coracoid
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, Montana, US
Referred- ?(ANSP 15867) proximal coracoid (Hope, 2002)
Diagnosis- (after Hope, 2002) twice the size of Cimolopteryx rara; neck of the shaft flatter and broader; the foramen for N. supracoracoideus less recessed from the scapular facet and much less steeply angled in its course than in C. rara.
(after Longrich et al., 2011) ear-shaped glenoid; shallow acrocoracoid fossa; tear-drop shaped scapular facet with straight medial edge; strong caudal extension of the glenoid around the scapular facet.
Comments- The paratype UCMP 53957 was reassigned to Lancian Ornithurine F by Longrich et al. (2011). Longrich et al. (2011) stated "no features were found that support referral of this form to Cimolopteryx and this assignment was not supported by our analysis." It fell out in Aves in their phylogenetic analysis based on Clarke's matrix.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
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.

"Cimolopteryx" minima Brodkorb, 1963
= Lamarqueavis minima (Brodkorb, 1963) Agnolín, 2010
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53976) proximal coracoid
Diagnosis- (after Longrich et al., 2011) broad, dorsoventrally compressed coracoid shaft; strongly triangular scapular cotyle; glenoid deflected away from shaft in dorsal view; lateral edge of glenoid straight in lateral view.
Comments- Longrich et al. (2011) found no characters to support the referral of minima to Cimolopteryx, though it did fall out in Aves in their phylogenetic analysis based on Clarke's matrix. Agnolín (2010) later referred it to his new genus Lamarqueavis, but Mohr et al. (2021) indicated it lacks the proposed generic characters of distally extended procoracoid process, medially straight to convex procoracoid process, and distally straight ("subrectangular") glenoid, although it does share a transversely elongate glenoid contra Mohr et al..
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
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.
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.

"Cimolopteryx" petra Hope, 2002
= Lamarqueavis petra (Hope, 2002) Agnolín, 2010
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (AMNH 21911) proximal coracoid
Diagnosis- (after Longrich et al., 2011) teardrop-shaped scapular cotyle; glenoid that is strongly angled inwards in dorsal view; absence of an acrocoracoid medial fossa.
Comments- Though Longrich (2009) stated Cimolopteryx petra is identical to C. rara except smaller and referred it to that species, he later (Longrich et al., 2011) stated "the differences are too extensive to warrant referral to the same genus and such an assignment is not supported by phylogenetic analysis." It fell out in Aves in their phylogenetic analysis based on Clarke's matrix. Agnolín (2010) later referred it to his new genus Lamarqueavis, but Mohr et al. (2021) indicated it lacks the proposed generic characters of distally extended procoracoid process and medially straight to convex procoracoid process, although it does share a distally straight ("subrectangular") glenoid and transversely elongate glenoid contra Mohr et al..
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. 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.
Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
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.
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.

Ceramornis Brodkorb, 1963
C. major Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53959) proximal coracoid
Diagnosis- (after Longrich et al., 2011) depression on lateral surface of coracoid posteroventral to glenoid; prominent acrocoracoid medial fossa; ovoid glenoid.
Comments- Brodkorb (1963) originally placed this taxon in Cimolopterygidae within Charadriiformes. Hope (2002) notes this taxon shows a few plesiomorphic charadriiform-like characters, but lacks charadriiform synapomorphies. Longrich et al. (2011) included it in a version of Clarke's analysis and found Ceramornis to be in Aves. Agnolín (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- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. in Sibley (ed.), Proceedings of the 13th International Ornithological Congress. American Ornithologists' Union. pp. 50-70.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
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.
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 'cimolopterygid' (Hope, 2002)
Late Campanian, Late Cretaceous
Upper Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1993.019.0001; Ornithurine E; Steveville bird) proximal coracoid
Diagnosis- (after Longrich, 2009) scapular cotyle strongly teardrop-shaped; supracoracoideus nerve foramen open.
Comments- Hope (2002) listed this as Aves Undetermined Species 4 and considered it similar to Iaceornis (her Apatornis). Longrich (2009) assigned this to his Ornithurae sensu Gauthier and de Quieroz based on an anteriorly placed scapular facet. Agnolín (2010) suggested it was a cimolopterygid, but Mohr et al. (2021) correctly noted it lacks most of his proposed characters for the family- distally extensive procoracoid process; distally placed and supracoracoid foramen; laterally angled glenoid; although I note the supracoracoid foramen is indeed enlarged like the Irvine bird although also open unlike that specimen.
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. 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.
Agnolín, 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 'cimolopterygid' (Hope, 2002)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (TMP 1993.116.0001; Ornithurine F; Onefour bird) proximal coracoid
Diagnosis- (after Longrich, 2009) subtrapezoidal humeral articular facet; anterior surface of coracoid forms a sharp ridge; scapular cotyle weakly teardrop-shaped; very small size.
Comments- Hope (2002) referred this specimen to Cimolopteryx sp. based on unspecified features in her diagnosis of that genus. Longrich (2009) stated it differs from Cimolopteryx in lacking a strong convex ridge on the inside of the triosseal canal and having a quadrangular glenoid. He assigned it to his Ornithurae sensu Gauthier and de Quieroz based on an anteriorly placed scapular facet. Agnolín (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 (unpreserved due to proximal breakage); laterally angled glenoid.
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.
Agnolín, 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 'cimolopterygid' (Mohr, Acorn, Funston and Currie, 2021)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (UALVP 55089; Ornithurine G) proximal coracoid
Comments- Mohr et al. (2021) referred to this as "Ornithurine G (cf. Cimolopteryx)" and noted while it "shares features with Cimolopteryx, the uncertainty regarding Cimolopterygidae as a whole prevents a definitive referral to this group."
Reference- 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 'cimolopterygid' (Tokaryk and James, 1989)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (AMNH coll.) proximal coracoid (Longrich et al., 2011)
(UCMP 53962) proximal coracoid (Hope, 2002)
(UCMP 53963) proximal coracoid (Hope, 2002)
Late Maastrichtian, Late Cretaceous
Frenchman Formation, Saskatchewan, Canada;
(SMNH P1927.936) proximal coracoid (Tokaryk and James, 1989)
Comments- Hope (2002) referred the UCMP and SMNH specimens to Cimolopteryx rara. Longrich (2009) states these specimens are not referrable to Cimolopteryx rara (citing personal observation) and refers to them as "Cimolopteryx" n. sp.. Longrich et al. (2011) later determined the material does not share apomorphies with Cimolopteryx, though its position in Aves remains uncertain. They term it Lancian Ornithurine A.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19,55-70.
Tokaryk and James, 1989. Cimolopteryx sp. (Aves, Charadriiformes) from the Frenchman Formation (Maastrichtian), Saskatchewan. Canadian Journal of Earth Sciences. 26, 2729- 2730.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. 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.
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.

unnamed possible 'cimolopterygid' (Agnolín, 2010)
Maastrichtian, Late Cretaceous
Allen Formation, Río Negro, Argentina
Material- (MML 208) proximal coracoid
Comments- This was referred to cf. Cimolopterygidae by Agnolín (2010).
Reference- Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.

unnamed Aves (Morrison, Dyke and Chiappe, 2005)
Late Campanian, Late Cretaceous
Northumberland Formation of the Nanaimo Group, British Columbia, Canada
Material- (RBCM.EH2005.003.0001.A) tarsometatarsus (34 mm) (Morrison, Dyke and Chiappe, 2005)
(RBCM.EH2005.003.0001.B) proximal tarsometatarsus (Morrison, Dyke and Chiappe, 2005)
Comments- Morrison et al. (2005) referred these to Ornithurae based on several characters- "metatarsal III displaced plantarly with respect to metatarsals II and IV; well-developed intercondylar eminence and hypotarsal crests; presence of a proximal vascular foramen" and in RBCM.EH2005.003.0001.A "a trochlea of metatarsal III that is rounded and well developed." However, hypotarsal crests are further restricted to Aves. Morrison et al. note they are not conspecific as "they differ markedly in size, as well as in the shape, of the hypotarsal area."
Reference- Morrison, Dyke and Chiappe, 2005. Cretaceous fossil birds from Hornby Island (British Columbia). Canadian Journal of Earth Sciences. 42(12), 2097-2101.

unnamed Aves (Elzanowski and Brett-Surman, 1995)
Late Maastrichtias, Late Cretaceous
Hell Creek Formation, Montana, US
Material- (UCMP 117598) premaxilla (Elzanowski and Brett-Surman, 1995)
(UCMP 117599) distal tarsometatarsus (Elzanowski and Brett-Surman, 1995)
(UCMP 129143; Lancian Ornithurine B) proximal coracoid (Longrich, Tokaryk and Field, 2011)
Comments- Elzanowski and Brett-Surman (1995) thought the premaxilla resembled most scolopacids and Nycticryphes in having a median ventral groove extending to the anterior tip, but was unlike these taxa in being prokinetic. The tarsometatarsus was noted to be similar to anseriforms in the distally placed vascular foramen (ventrally), with anatids in the compact trochlea, and with Presbyornis in the large distal vascular foramen. However, other characters are more similar to Chionis and gruoids. Stidham (2001) considered it more likely related to stem-mirandornithine Junctitarsus without comment. Longrich et al. (2011) described the coracoid as Lancian Ornithurine B, recovering it in Aves using Clarke's bird analysis.
References- Elzanowski and Brett-Surman, 1995. Avian premaxilla and tarsometatarsus from the Uppermost Cretaceous of Montana. Auk. 112, 762-766.
Stidham, 2001. The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes). PhD Thesis, University of California. 257 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.

unnamed avian (Longrich, Tokaryk and Field, 2011)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (AMNH 13011) proximal coracoid
(USNM 181923) proximal coracoid
Diagnosis- (after Longrich et al., 2011) ovate scapular facet; glenoid laterally deflected in dorsal view.
Comments- Longrich et al. (2011) described these as Lancian Ornithurine E, recovering it in Aves using Clarke's bird analysis.
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.

unnamed avian (Brodkorb, 1963)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (ACM 12359) proximal coracoid (Longrich et al., 2011)
(UCMP 53957) proximal coracoid (Brodkorb, 1963)
Diagnosis- (after Longrich et al., 2011) paddle-shaped glenoid; massive medial edge to the glenoid; large scapular facet; large scapular facet that is wider mediolaterally than long anteroposteriorly.
Comments- UCMP 53957 was a paratype of Cimolopteryx maxima (Brodkorb, 1963), which was followed by Hope (2002). It was reassigned to Lancian Ornithurine F by Longrich et al. (2011).
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19,55-70.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
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.

undescribed avian (Hope, 2002)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (UCMP 53960) two cervical vertebral fragments
Comments- Questionably referred to Torotix by Brodkorb in the UCMP catalog.
Reference- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Aves indet. (Kurochkin, 1988)
Late Campanian, Late Cretaceous
Udyn Sayr, Baruungoyot Formation, Mongolia
Material- (?PIN coll.) tarsometatarsus (40.3 mm)
Comments- Referred to the Presbyornithidae by Kurochkin (1988, 2000), but said to be undiagnostic past Aves by Kurochkin et al. (2002).
References- Kurochkin, 1988. [Cretaceous birds of Mongolia and their significance for study of the phylogeny of class Aves.] Trudy Sovmestnoi Sovetsko-Mongol’skoi Paleontologicheskoi Ekspeditsii. 34, 33-42.
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. 544-559.
Kurochkin, Dyke and Karhu, 2002. A new presbyornithid bird (Aves, Anseriformes) from the Late Cretaceous of southern Mongolia. American Museum Novitates. 3386, 1-11.

unnamed avian (Clarke and Norell, 2004)
Early Maastrichtian, Late Cretaceous
Tsaagan Khushu, Nemegt Formation, Mongolia
Material- (IGM 100/1309) proximal humerus
Comments- Diuscovered in 2001, IGM 100/1309 was described by Clarke and Norell (2004) and recovered as a member of crown Aves using Clarke's avialan matrix.
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 avian (Kakegawa, 1998)
Campanian, Late Cretaceous
Orannai Formation, Japan
Material- (NSMJ coll.) sacrum, scapula, pelvis, fibula, pedal phalanx
References- Kakegawa, 1998. The Late Cretaceous Aves from Wakkanai, Hokkaido. (Kagawa University, March 1998). Master's Thesis.
Kakegawa, 1998. A Late Cretaceous aquatic bird from Hokkaido Japan. SVPCA.

unnamed avian (Agnolín and Novas, 2012)
Campanian-Maastrichtian, Late Cretaceous
Allen Formation, Río Negro, Argentina
Material- (MML 206) incomplete carpometacarpus (21 mm)
Comments- While Agnolín and Novas (2012) could distinguish this from Iaceornis and the coocuuring Limenavis, they could not place it more precisely in Aves.
Reference- Agnolín and Novas, 2012. A carpometacarpus from the Upper Cretaceous of Patagonia sheds light on the ornithurine bird radiation. Paläontologische Zeitschrift. 86, 85-89.

unnamed probable avian (Agnolín and Martinelli, 2009)
Campanian-Maastrichtian, Late Cretaceous
Los Alamitos Formation, Río Negro, Argentina
Material- (MACN PV RN 1115) distal tarsometatarsus
Reference- Agnolín and Martinelli, 2009. Fossil birds from the Late Cretaceous Los Alamitos Formation, Río Negro province, Argentina. Journal of South American Earth Sciences. 27, 42-49.

undescribed Aves (Case and Tambussi, 1999)
Late Campanian-Early Maastrictian, Late Cretaceous
Cape Lamb Member of the Snow Hill Island Formation, Vega Island, Antarctica
Material- (AMNH 30920) incomplete dorsal vertebra (Roberts et al., 2014)
(MLP 98-I-10-25; = St. Mary's College coll.) incomplete tarsometatarsus (Case and Tambussi, 1999)
Comments- Case and Tambussi (1999) referred MLP 98-I-10-25 to Charadriiformes. The material is figured in Reguero et al. (2013). Roberts et al. (2014) stated it was "relatively elongated with hypotarsal crests but not enclosed canals. Assuming this is the case, it would show morphologies consistent with a phylogenetic placement within or very close to the crown clade." Acosta Hospitaleche et al. (2019) stated "this material is not complete enough for any certain systematic assignment."
AMNH 30920 was found in 2011 and figured by Roberts et al. (2014), who stated "its weakly heterocoelous centrum is consistent with its belonging to an ornithurine that is closer to the crown clade than Ichthyornis, or perhaps even a member of Neornithes."
References- Case and Tambussi, 1999. Maestrichtian record of neornithine birds in Antarctica: Comments on a Late Cretaceous radiation of modern birds. Journal of Vertebrate Paleontology. 19(3), 37A.
Reguero, Tambussi, Coria and Marenssi, 2013. Late Cretaceous dinosaurs from the James Ross Basin, west Antarctica. Geological Society, London, Special Publications. 381, 99-116.
Roberts, Lamanna, Clarke, Meng, Gorscak, Sertich, O'Connor, Claeson and MacPhee, 2014. Stratigraphy and vertebrate paleoecology of Upper Cretaceous-?lowest Paleogene strata on Vega Island, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology. 402, 55-72.
Acosta Hospitaleche, Jadwiszczak, Clarke and Cenizo, 2019. The fossil record of birds from the James Ross Basin, west Antarctica. Advances in Polar Science. 30(3), 250-272.

undescribed Aves (Roberts, Lamanna, Clarke, Meng, Gorscak, Sertich, O'Connor, Claeson and MacPhee, 2014)
Late Maastrictian, Late Cretaceous
Sandwich Bluff Member of the Lopez de Bertodano Formation, Vega Island, Antarctica
Material- (AMNH 30898) incomplete coracoid
(AMNH coll.) multiple specimens
femora, tibia (Coria et al., 2015)
Comments- Roberts et al. (2014) figure a coracoid discovered in 2011 as "partial coracoid of unidentified bird recovered from concretion", which is here placed in Aves due to the deep lateral process and concave lateral edge. Additionally they list Ornithurae indet. from unit SBM12 and Aves indet. (sensu Chiappe) from units SMBM1, 2, 7 and 10-12. Thus at least seven new specimens are known. The authors state "in our view, all of these remains are referable to Ornithurae, and some (e.g., Vegavis) are also part of the crown clade", so they are provisionally retained as Aves here.
Coria et al. (2015) report "avian femori and tibia collected from the same levels of the anseriform Vegavis" in 2015.
References- Roberts, Lamanna, Clarke, Meng, Gorscak, Sertich, O'Connor, Claeson and MacPhee, 2014. Stratigraphy and vertebrate paleoecology of Upper Cretaceous-?lowest Paleogene strata on Vega Island, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology. 402, 55-72.
Coria, O'Gorman, Cardenas, Gouiric-Cavalli, Mors, Chornogubsky and Lopez, 2015. Late Cretaceous vertebrates from Isla Vega, Antarctica: Reports from the 2015 fieldwork. XXIX Jornadas Argentinas de Paleontología de Vertebrados, resumenes. Ameghiniana. 52(4) suplemento, 27-28.

Panpalaeognathae Gauthier and de Queiroz, 2001
Definition- (Struthio camelus, Tinamus major <- Gallus gallus, Vultur gryphus) (Gauthier and de Queiroz, 2001)

Antarcticavis Cordes-Person, Acosta Hospitaleche, Case and Martin, 2020
= "Antarcticavis" Cordes-Person, Acosta Hospitaleche, Case and Martin, 2019 online
A. capelambensis Cordes-Person, Acosta Hospitaleche, Case and Martin, 2020
= "Antarcticavis capelambensis" Cordes-Person, Acosta Hospitaleche, Case and Martin, 2019 online
Late Campanian-Early Maastrichtian, Late Cretaceous
Cape Lamb Member of the Snow Hill Island Formation, Vega Island, Antarctica
Holotype- (SDSM 78147; = field number VI 9901) two ?posteriormost dorsal vertebrae, dorsal rib fragment, synsacrum, scapula (~71 mm), coracoids (37.6 mm; one distal), partial sternum, sternal ribs, humeri (94.9 mm), proximal radius, proximal ulnae, proximal carpometacarpi, distal carpometacarpus, ilium, femora (one incomplete), proximal tibiotarsus, distal tibiotarsi, proximal fibula, proximal tarsometatarsus
Diagnosis- (after Cordes-Person et al., 2020) synsacrum formed by eleven vertebrae; absence of supracoracoid foramen; keeled sternum; metacarpal I with ball-like distal articulation; preacetabular process elongated; non-ossified supratendinal bridge; tibiotarsus with developed sulcus cartilaginis tibialis; distal tibiotarsal articulation posteriorly extended; lateral condyle of tibiotarsus wider than medial condyle; tibiotarsal intercondylar sulcus about 1/3 width of anterior surface; fibula not reduced proximally; proximal metatarsals coplanar; hypotarsal sulcus well developed.
Comments- The holotype was discovered in 1999 (Cordes-Person pers. comm., 11-9-2020) and initially believed to be a charadriiform, potentially a burhinid (Cordes, 2001, 2002). The 2002 SVP abstract mentions two cervical vertebrae that were not in the final description. The paper describing it was initially only available as a journal pre-proof posted on November 18 2019 that did not mention Zoobank, which according to ICZN Article 8.5.3 (a 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"), made "Antarcticavis capelambensis" Cordes-Person et al. 2019 a nomen nudum until the issue was published in April 2020. Cordes-Person et al. (2020) added Antarcticavis to O'Connor's avialan analysis and recovered it sister to Vegavis plus Anas plus Gallus, with no other avians included. Adding it to Hartman et al.'s maniraptoromorph analysis results in it being a panpalaeognath less closely related to living taxa than lithornithids or Limenavis.
References- Cordes, 2001. A basal charadriiform bird from the Early Maastrichtian of Cape Lamb, Vega Island, Antarctic Peninsula. Masters Thesis, South Dakota School of Mines and Technology. 71 pp.
Cordes, 2002. A new charadriiform avian specimen from the Early Maastrichtian of Cape Lamb, Vega Island, Antarctic Peninsula. Journal of Vertebrate Paleontology. 22(3), 46A.
Cordes-Person, Acosta Hospitaleche, Case and Martin, 2020 (online 2019). An enigmatic bird from the lower Maastrichtian of Vega Island, Antarctica. Cretaceous Research. 108, 104314.

Eogranivora Zheng, O'Connor, Wang, Wang and Zhou, 2018
E. edentulata Zheng, O'Connor, Wang, Wang and Zhou, 2018
Early Aptian, Early Cretaceous
Dawangzhangzi, Dawangzhangzi Beds of Yixian Formation, Liaoning, China
Holotype- (STM 35-3) skull (37 mm), mandibles, hyoid, nine cervical vertebrae, four dorsal vertebrae, dorsal ribs, synsacrum, first-sixth caudal vertebrae, pygostyle (7.6 mm), partial scapulae, coracoids (20.5, 21 mm), furcula, sternum (~36.3 mm), sternal ribs, humeri (57.2, 60.7 mm), radii (57.7, 61 mm), ulnae (60.1, 62.4 mm), scapholunare, pisiforms, carpometacarpi (27, 28.9 mm; mcI 5.2, 5.4 mm; mcII 26.3, 27 mm; mcIII 26, 25 mm), phalanges I-1 (9.3, 9 mm), manual unguals I (4.9, 5.8 mm), phalanges II-1 (12.6, 13 mm), phalanges II-2 (11.1, 10.2 mm), manual unguals II (3, 2.7 mm), phalanx III-1 (~5 mm), phalanges III-2 (~1.5 mm), ilia (~25 mm), ischia (25.1, ~17.6 mm), femora (36, 39 mm), tibiotarsi (45.7, 47.4 mm), fibulae (23.7, 24.1 mm), tarsometatarsi (~18.7, 19.7 mm; mtII 16.6, mtIII 17.8, mtIV ~15.8 mm), phalanx II-1 (~4 mm), phalanx II-2 (~4 mm), pedal ungual II, phalanx III-1 (~4.9 mm), phalanx III-2 (4.4 mm), phalanx III-3 (3.9 mm), pedal ungual III (5.3 mm), phalanx IV-1, phalanx IV-2, phalanx IV-3 (~3.2 mm), phalanx IV-4 (~2.5 mm), pedal ungual IV, pedal phalanges, pedal unguals, body feathers, remiges, retrices, ?egg, seeds in crop, ~112 gastroliths
Diagnosis- (after Zheng et al., 2018) dentary symphysis occupying anterior 20% of mandible; coracoid without distinct sternolateral process; posterolateral and posteromedial sternal processes narrow and extend posteriorly to the same level; posteromedian process V-shaped; short and robust manual digit I; metatarsal I and hallux absent.
Other diagnoses- Zheng et al. (2011) include the character "dorsomedially oriented bluntly triangular process present on pubes located one-third of the length from the proximal end", but this is probably invalid following the reidentification of pubes as ischia by Mortimer (online 2018). Additionally, the complete lack of teeth would be expected in a member of crown Aves, so would not be an autapomorphy if its placement here is correct.
Comments- This was initially briefly described as a specimen of Hongshanornis without justification (Zheng et al., 2011). Zheng et al. (2018) redescribed the specimen as a new taxon of basal ornithuromorph. Mortimer (online 2018) noted that the supposed pubes are more likely ischia, as the otherwise autapomorphic posterodorsal pubic process would correspond to the standard posterodistal ischial process of euornithines and the posterior margin between the element and ilium leaves no room for a missing ischium. Zheng et al. (2018) used O'Connor's avialan matrix (which lacks panpalaeognaths) to recover Eogranivora as a basal ornithuromorph in a polytomy with several taxa such as Jianchangornis, Schizooura, Zhongjianornis and Xinghaiornis. The Hartman et al. maniraptoromorph matrix recovers Eogranivora as a panpalaeognath less closely related to living taxa than lithornithids or Limenavis.
References- 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.
Mortimer, online 2018. https://theropoddatabase.blogspot.com/2018/02/is-eogranivoras-pelvis-misinterpreted.html
Zheng, O'Connor, Wang, Wang and Zhou, 2018. Reinterpretation of a previously described Jehol bird clarifies early trophic evolution in the Ornithuromorpha. Proceedings of the Royal Society B. 285(1871), 20172494.

Limenavis Clarke and Chiappe, 2001
L. patagonica Clarke and Chiappe, 2001
Campanian-Maastrichtian, Late Cretaceous
Allen Formation, Río Negro, Argentina
Holotype- (PVL 4731) distal humerus, proximal radius, proximal and distal ulna, scapholunare, partial pisiform, proximal and distal carpometacarpus, incomplete phalanx II-1, fragments
Diagnosis- (after Clarke and Chiappe, 2001) three fossae on the proximal surface of the dorsal supracondylar process of the humerus (also in Ichthyornis, Lithornis and Torotix); attachment of the pars ulnaris of the trochlea humeroulnaris on the proximal ulna developed as a pit-shaped fossa; scar of the ligamentum collaterale ventrale of the ulna proximodistally elongate, extending down the caudal margin of the brachial impression (also in Podiceps, Gavia, Balaeniceps, Grus, Numenius and Burhinus); deep infratrochlear fossa proximal to pisiform process on carpometacarpus (also in Ichthyornis, Lithornis, Podiceps, some procelariiforms, Rallus and cuculiforms); pisiform process with its proximal surface at approximately the same level as the proximal surface of metacarpal I.
Other diagnoses- Clarke and Chiappe (2001) also included the deep tendinal groove of the pisiform in their diagnosis, but this is present in most Aves except ratites, Chauna, possibly galliforms, and some diving taxa.
Comments- The holotype was discovered in the mid 1980's but only described in 2001 by Clarke and Chiappe. Those authors used a matrix consisting mostly of forelimb characters to place Limenavis as a carinate more derived than Ichthyornis, but less so than Lithornis and Aves. Clarke (2002) scored Limenavis in her large cladistic analysis and found it to be a carinate more derived than Ichthyornis, but less than Iaceornis and Aves (including Lithornis), agreeing with the results of the earlier study.
Limenavis a carinate? Clarke and Chiappe (2001) placed Limenavis closer to Aves than Ichthyornis based on two characters. The articular surface of the dorsal ulnar condyle is proximally truncated and the carpal tubercle of the ulna is absent. Neither are known for non-carinates, and at least the latter is also untrue in Apsaravis, though each does exhibit some variation within Aves.
Clarke (2002) placed Limenavis closer to Aves than Ichthyornis because its metacarpal I extensor process is supposedly more projected, but this seems to be untrue. The projection perpendicular to the carpometacarpus shaft from the medial concavity in metacarpal I (compared to the width from the medial condyle of metacarpal I to the lateral carpometacarpal edge) is 18% in Ichthyornis and 16% in Limenavis. Limenavis' is more robust and more highly angled anteriorly, but the distribution of these attributes is as of yet unstudied.
Thus one character places Limenavis in Carinatae and another places it closer to Aves than Apsaravis.
Limenavis outside Aves? Only one character in Clarke and Chiappe's (2001) study supports its exclusion from Lithornis+Aves - metacarpal III ends proximal to metacarpal II. This is also found in anseriforms, stem galliforms, Phaethon, Mesitornis, Pterocles, gaviids, procelariiforms, steganopodes and charadriiforms. Four additional characters support placing Limenavis and Lithornis outside Aves, but as other analyses are consistant in placing Lithornis within Aves, these could equally well support placing Limenavis in Lithornithidae. Of these characters, the loss of two small fossae on the dorsal supracondylar tubercle of the distal humerus and loss of a deeply excavated infratrochlear fossa of the carpometacarpus are forelimb simplifications that may have been lost in crown palaeognaths simply due to their reduced wings. The third character (lateral margin of manual phalanx II-1 straight) is also found in Neoaves in their matrix, making the strongly convex margin equally likely to have converged in crown palaeognaths and galloanserines as opposed to being basal for Aves. The last character (interosseal groove absent on distal carpometacarpus) is distributed sporadically throughout Aves, being present in Gallus, Anas and charadriiforms in their matrix for instance.
Clarke (2002) only used one different character to exclude Limenavis from Aves + Iaceornis (here viewed as an avian)- the less projected extensor process on metacarpal I. However, they note that various neoavians have equally low processes, and palaeognaths including lithornithids do as well.
In conclusion, all of the proposed characters to exclude Limenavis from Aves are widespread in that clade, with five of the six being present in Lithornis. It may most parsimoniously be a lithornithid, though any firm conclusions on its affinities await a more detailed comparison to basal avians.
References- Clarke and Chiappe, 2001. A new carinate bird from the Late Cretaceous of Patagonia (Argentina). American Museum Novitates. 3323, 1-23.
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.

Lithornithidae Houde, 1988

Palaeognathae Pycraft, 1900
Official Definition- crown (Struthio camelus + Tinamus major) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Gauthier and de Queiroz, 2001; Registration Number 695)
References- Pycraft, 1900. On the morphology and phylogeny of the Palaeognathae (Ratitae and Crypturi) and Neognathae (Carinatae). The Transactions of the Zoological Society of London. 15(5), 149-290.
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.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Struthioniformes

Notopalaeognathae Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Rhea americana + Tinamus major + Apteryx australis) ( Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 696)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Dinocrypturi Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- (Tinamus major + Dinornis novaezealandiae) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 698)
Reference- Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Dinornithiformes

Tinamiformes

Rheiformes

Novaeratitae Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Apteryx australis + Casuarius casuarius) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 697)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Casuariiformes

Aepyornithiformes

Apterygiformes

Panneognathae Gauthier and de Queiroz, 2001
Definition- (Pluvialis apricaria <- Struthio camelus, Tinamus major) (Gauthier and de Queiroz, 2001)
Reference- 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.

Iaceornis Clarke, 2004
Definition- (YPM 1734 <- Ichthyornis dispar, Struthio camelus, Tetrao major, Vultur gryphus) (new)
Other definitions- (YPM 1451 <- Ichthyornis dispar, Struthio camelus, Tetrao major, Vultur gryphus) (modified from Clarke, 2004)
= "Iaceornis" Clarke, 2002
Comments- Clarke (2004) accidentally defined Iaceornis identically to Apatornis, so I have provided the definition that was intended as a substitute until a formal correction is published.
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.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History. 286: 1-179.
I. marshi Clarke, 2004
Definition- (the species that includes YPM 1734) (Clarke, 2004)
= "Iaceornis marshi" Clarke, 2002
Early Campanian, Late Cretaceous
Hesperornis Zone of the Smoky Hill Chalk Member of the Niobrara Formation, Kansas, US
Holotype- (YPM 1734) dorsal rib, scapulae (52.5 mm), coracoids (24 mm), partial furcula, incomplete sternum, proximal radius, scapholunare, pisiform, carpometacarpus (36 mm), phalanx II-1 (14 mm), phalanx II-2 (13 mm), ilium (50 mm; lost), pubis (32 mm; lost), ischium (lost), partial femur, incomplete tibiotarsus, fibula (28 mm; lost), fragments
Diagnosis- (after Clarke, 2004) hooked acromion (also in Apsaravis and Lithornithidae).
Other diagnoses- Clarke (2004) listed the strongly tapering omal furcular tip as an apomorphy, but this is also present in Archaeorhynchus, Yixianornis, Anseriformes, Mirandornithes, many Charadriiformes, Gaviidae and Procellariimorphae.
Comments- This specimen was discovered in 1877 and originally referred to Apatornis celer by Marsh (1880), though it is not comparable to the Apatornis holotype. Because of its completeness compared to the Apatornis holotype, it has been the basis of most authors' understanding of the genus since then, until Clarke separated it in 2002 (published in 2004) as Iaceornis. The pelvis which has been the most commonly illustrated portion of the specimen was lost prior to 1955. Both Marsh (1880) and Clarke (2004) described numerous features which differ from Ichthyornis, though Marsh and most authors until Clarke (2002, 2004) were wrong in believing the tibiotarsus lacked a supratendinal bridge. Howard (1955) thought YPM 1734 (as Apatornis) was similar to her new taxon Telmabates (described as a phoenicopteriform but now recognized as a presbyornithid anseriform) and might be referrable to Phoenicopteriformes itself, though she felt a more thorough review should take place before any official reclassification. Martin (1987) described cervical and humeral characters of Apatornis, but these elements are not preserved in the holotype or YPM 1734.
Iaceornis an ichthyornithine? Marsh (1880) considered YPM 1734 part of his Odontotormae when he described it, though never explicitly defended the view. It does share a keeled sternum, large wings and a carpometacarpus with Odontotormae as listed on page 187, but most Aves have these characters too. While this has been followed by most authors since, it seems more due to stratigraphy and tradition than actual character support.
Iaceornis an anseriform? Howard (1955) listed several characters she thought were similar in YPM 1734 and the presbyornithid Telmabates (though she viewed the latter as a phoenicopteriform, so viewed the characters as supporting placement of YPM 1734 in that order). The crossed coracoid sulci on the sternum are similar to not only Phoenicopterus and Telmabates, but also Ichthyornis, casuariids, Phaethon, Leptosomus, Steatornis, ciconiiforms, accipitrids and several other neoavians. The broadly rounded anterior sternal edge is plesiomorphic for euornithines. The short shaft and flaring sternal end of the coracoid were said to be similar to Telmabates, Phoenicopterus and the basal phoenicopteriform Paloelodus, but these are plesiomorphies which are also seen in such taxa as Gansus, Ichthyornis and Lithornis. The scapular facet of the coracoid being both round and deep was said to be most similar to Telmabates, and while similarly round facets are present in many euoprnithines and some look comparatively deep in figures (e.g. Cimolopteryx rara, Palintropus), the distribution of these features over Aves has yet to be studied. The supracoracoid foramen is in a similar position not only to Telmabates, but also to taxa such as Lithornis, Ichthyornis and Yixianornis. The scapula was merely said to resemble Telmabates, which is too vague for comment. A well developed ulnar facet on the proximal radius is also present in Limenavis and Eonessa in addition to Telmabates. The greatly expanded dorsal trochlea on the carpometacarpus is also present in the pangalliform Paraortygoides, Limenavis, Apsaravis and Yixianornis in addition to Telmabates. The carpal trochlea which extends distally to metacarpal III is indeed similar to Telmabates and the presbyornithid Teviornis and not seen in other Mesozoic euornithines. However, lithornithids and Paraortygoides share this feature as well. The extensor process of metacarpal I is fairly similar to Telmabates and Teviornis in being more elongate than any non-avian taxon and having a generalized triangular shape with proximally placed apex (as in Ichthyornis and Limenavis, though theirs are less elongate), but the lithornithid Pseudocrypturus shares this. According to Howard, in both YPM 1734 and Telmabates, the internal edge of metacarpal III is placed ventral to the ventral crest of the carpal trochlea, but this seems to be true in Apsaravis, Ichthyornis and Limenavis as well as in Teviornis. A trochanteric crest which extends proximal to the ilial facet on the femur is unlike other Mesozoic birds, but is seen in many Aves such as Paraortygoides, Pheonicopterus and the lithornithid Paracathartes.
Hope (2002) suggested the "short, angular" coracoid glenoid was similar to some anseriforms and other Aves, but indeed even Ichthyornis' could be described this way. The long, pointed acromion was said to be similar to anatoids, but is also seen in Ambiortus and Yixianornis. Hope also cited the laterally protruding distal end of the scapular glenoid "with surrounding shelf tapered distally" as a feature shared specifically with presbyornithids, though these are difficult to evaluate in most Mesozoic euornithines based on the literature alone. The ventromedial edge of the acrocoracoid process is raised as a lip which expands anteriorly in Iaceornis and Anatoidea, but this seems true of Apsaravis and Ichthyornis too. Finally, Hope states that Iaceornis' scapula is more similar to Presbyornis than Juncitarsus (a probable stem mirandornithine) in having a strongly concave dorsal edge anteriorly, but the edge in Iaceornis is actually convex and thus unlike both.
The evidence for an anseriform affinity seems weak, with only the scapular glenoid morphology described by Hope being potentially synapomorphic.
Iaceornis a non-avian ornithurine? Elzanowski (1995) placed YPM 1734 outside Aves based on two characters. The acromion was said to be longer than basal avians, but some (e.g. lithornithids, anatoids, Gallus, pelecanids, Cariama) have elongate acromia as well. The supratendinal bridge was said to be absent on the tibiotarsus, but this was a mistake by Marsh.
Clarke (2002, 2004) found Iaceornis to be outside Aves in her analysis based on four characters. There are no pneumatic foramina between the sternal rib articulations, but this is true of many avians as well, including apterygids, phasianoids, most Natatores, most charadriiforms and columbiforms. Similarly, the non-pneumatic coracoid is present in anatids, presbyornithids, and many pangalliforms including the basal Gallinuloides. Metacarpal III does not extend distally past metacarpal II, but this is also true in many Aves such as Pterocnemia, Telmatornis, Telmabates, Teviornis, Anas, Walbeckornis, Miodytes, Limnofregata, gruiforms and charadriiforms. Finally, the medial tibiotarsal condyle projects further anteriorly than the lateral condyle. This is found in numerous Aves however, including Anas, galliforms, most metavians, most Natatores, some charadriiforms and many others.
Despite being the conclusion of the only phylogenetic analysis to include Iaceornis, there is no unambiguous evidence the taxon is outside Aves. This is due in part to the huge variation in the clade, which was only represented in Clarke's matrix by two palaeognaths and four galloanserines. While it might be argued any character diagnosing Aves would be expected to reverse in some example, the preliminary comparisons above suggest some groups contain taxa which match all of Iaceornis' supposedly non-avian characters (e.g. anseriforms, galliforms).
Iaceornis closer to Aves than Ichthyornis? While Howard (1955) implicitly proposed this possibility when allying YPM 1734 with phoenicopteriforms, Clarke (2002, 2004) was the first to support it with characters found in basal avians. Paired intermuscular lines on the sternum and an intermetacarpal space ending distal to metacarpal I are also present in Gansus, which has always been resolved as basal to Ichthyornis in published analyses. The larger extensor process on metacarpal I and supratendinal bridge on the tibiotarsus are valid characters shared with neognaths and tinamids. Notably, lithornithids and ratites can lack all of these characters.
Hope (2002) noted the scapular facet on the coracoid was distal to the glenoid, unlike Ichthyornis. However, this also appears to be the case in Apsaravis and Yixianornis. Hope also stated the scapular glenoid was small and located anterolaterally, but the condition appears similar in Yixianornis. The scapular glenoid being much smaller than the coracoid glenoid does seem to be absent in non-avian euornithines where both can be observed though (Patagopteryx, Yixianornis, Ichthyornis), but is present in Tinamidae and Neognathae. Hope suggested the prominent acrocoracoid process was consistant with referral to Neognathae, but Gansus and Pseudocrypturus have similarly large processes.
While some of Clarke's and Hope's characters uniting Iaceornis with Aves have been found to be diagnostic of more inclusive clades thanks to recent discoveries (Gansus, Yixianornis, Apsaravis), the small scapular glenoid compared to the coracoid glenoid, large extensor process and supratendinal bridge do support this arrangement. Additionally, the well developed ulnar facet on the proximal radius, carpal trochlea which extends distally to metacarpal III, and trochanteric crest which extends proximal to the ilial facet on the femur noted by Howard as similar to Telmabates are only found in Aves (or in one case in Limenavis too, which is also closer to Aves than Ichthyornis) as well. Thus a placement closer to Aves than to Ichthyornis seems probable, while more exact affinities must await adding Iaceornis to a large matrix of avians. A relationship with galloanserines does seem plausible however, given the preliminary findings here.
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.
Howard, 1955. A new wading bird from the Eocene of Patagonia. American Museum Novitates. 1710, 25 pp.
Martin, 1987. The beginning of the modern avian radiation. Documents des Laboratoires de Geologie de la Faculte des Sciences de Lyon. 99, 9-20.
Elzanowski, 1995. Cretaceous birds and avian phylogeny. Courier Forschungsinstitut Senckenberg. 181, 37-53.
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. University of California Press. 339-388.
Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History. 286: 1-179.

Cerebavis Kurochkin, Saveliev, Postnov, Pervushov and Popov, 2006
C. cenomanica Kurochkin, Saveliev, Postnov, Pervushov and Popov, 2006
Middle Cenomanian, Late Cretaceous
Melovatskaya Formation, Russia
Holotype- (PIN 5028/2) (~80-160 g) mesethmoid, parabasisphenoid, braincase
Diagnosis- (after Kurochkin et al., 2006) cerebellar prominence present and very wide (= roof of midbrain with large auditory tubercles).
(after Walsh et al., 2015) frontals exceedingly narrow interorbitally; small depressions present on dorsolateral edge of frontals in posterior region of orbit roof; paroccipital processes very poorly developed; foramen for anterior carotid artery absent; parasphenoid lamina approximately square and projects ventrally beyond parasphenoid rostrum; small, dorsoventrally compressed basipterygoid processes; parasphenoid rostrum stout with conspicuous expansion at midpoint; large orbitocranial fonticuli extending anteriorly to olfactory nerve sulcus; optic nerve (II) foramen Type 3 (sensu Hall et al. 2009); trigeminal nerve (V) foramen slightly anterior to parasphenoid wing (also in most Aves except phaethontiforms, fregatids and some procellariiforms); ectethmoid poorly developed to absent; pterygoids rod-like, sigmoidal and possessing two distinct posterior processes.
Other diagnoses- Kurochkin et al. (2006) also listed the following, dismissed by Walsh et al. as untrue based on misinterpreting the braincase as an endocast- cerebral hemispheres rounded oval; olfactory tracts thick, with large olfactory bulbs; interhemispheric fissure shallow; parietal organ well pronounced, located in pineal recess on caudal slope of interhemispheric fissure; well-developed epiphysis (glandula pinealis) located between auditory tubercles; optic tubercles (lobi optici) located caudoventral to cerebral hemispheres, not projecting laterally beyond them; middle part of parasphenoid rostrum swollen.
Walsh et al. (2015) also included the following in their diagnosis- all skull roof cranial sutures obliterated (also in Ichthyornis and Aves); basipterygoid processes at base of parasphenoid rostrum (plesiomorphic).
Comments- The holotype was discovered in 1993. Though described as largely an endocast, Walsh et al. (2013; 2015) determined it is actually a braincase. This renders Kurochkin et al.'s (2006) diagnosis invalid, but while Walsh et al. originally claimed this makes the taxon a nomen dubium, they provided a diagnosis once the full paper was out. Walsh et al. described several characters of derived euornithines such as complete braincase fusion, a lack of a postorbital, and ossified eustachian tubes, yet stated the absence of a wulst excludes it from Aves.
References- Kurochkin, Saveliev, Postnov, Pervushov and Popov, 2006. On the brain of a primitive bird from the Upper Cretaceous of European Russia. Paleontological Journal. 40(6), 655-667.
Walsh, Milner and Bourdon, 2013. A reinterpretation of the brain morphology of Cerebavis cenomanica (Aves: incertae sedis). Journal of Vertebrate Paleontology. Program and Abstracts 2013, 234.
Walsh, Milner and Bourdon, 2015. A reappraisal of Cerebavis cenomanica (Aves, Ornithurae), from Melovatka, Russia. Journal of Anatomy. doi: 10.1111/joa.12406

Novacaesareala Parris and Hope, 2002
N. hungerfordi Parris and Hope, 2002
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (NJSM 11302) distal humerus, proximal radius, partial ulna, fragments
Diagnosis- (modified from Parris and Hope, 2002) humeral shaft slightly flattened craniocaudally; brachial fossa distinctly tripartite, divided by pronounced crests into the more proximal brachial fossa proper and a ventral and dorsal supracondylar fossa; brachial fossa proper divided into a shallow proximal shelf and much deeper dorsal pit; broad flexor process.
Comments- Olson and Parris (1987) tentatively assigned this specimen to Graculavidae. Parris and Hope (2002) note it closely resembles Torotix except for the broad flexor process, presbyornithids except for the narrow ventral brachial depression rim, pelecaniforms except for the unflared ventral epicondyle and flexor process, and both presbyornithids and pelecaniforms except for the craniocaudally flattened shaft (unreported in Torotix) and the more distally extended brachial fossa. Given that information, and the assignment of Torotix to Pelecaniformes or Presbyornithidae by different authors, it seems possible Novacaesareala could be referred to either clade. Most recently, Mayr and Scofield (2015) compared it favorably to the Paleocene phaethontiform Zhylgaia in the very short flexor process, elongate ventral supracondylar tubercle and marked brachial fossa.
Although Ford emmends the species name to hungerfordorum because it was named after multiple people, such emmendations aren't allowed according to the 1999 ICZN.
References- Olson and Parris, 1987. The Cretaceous Birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 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. 113-124.
Mayr and Scofield, 2015. New avian remains from the Paleocene of New Zealand: The first early Cenozoic Phaethontiformes (tropicbirds) from the Southern Hemisphere. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1031343

Qinornis Xue, 1995
Q. paleocenica Xue, 1995
Danian-Selandian, Paleocene, Paleogene
Fangou Formation, Shanxi, China
Holotype- (XD78sh048.3) (adult) tarsometatarsus (42 mm), phalanx II-1 (8.3 mm), phalanx II-2 (6.5 mm), pedal ungual II (2.4 mm), phalanx III-1 (9.3 mm), phalanx III-2 (7 mm), phalanx III-3 (5.8 mm), pedal ungual III (3.3 mm), phalanx IV-1 (6.85 mm), phalanx IV-2 (3.3 mm), phalanx IV-3 (3.5 mm), phalanx IV-4 (3.3 mm), pedal ungual IV (2.85 mm)
Paratypes- ....(XD78sh048.1) distal tibiotarsus
....(XD78sh048.2) incomplete tibiotarsus (~56 mm)
Comments- The type material was discovered in 1977-78 and described by Xue in 1995 as incertae sedis within birds. Xue considered the solid tarsometatarsus, incomplete tarsometatarsal fusion and open distal vascular foramen indicated the taxon either more basal than Aves or a subadult perhaps related to Charadriiformes or Gruiformes. Mayr (2007) thought the material was adult due to the fused distal tarsals and well defined distal articular surfaces, so considered it a possibly non-avian euornithine ("basal ornithurine" in his words) based on the incomplete tarsometatarsal fusion. This would be the first bird outside the crown group Aves to be recognized in the Tertiary, which is why it is included in this otherwise Mesozoic theropod website. However, it ends up in Neognathae when included in my modified version of Clarke's analysis.
References- Xue, 1995. Qinornis paleocenica - a Paleocene bird discovered in China. Courier Forschungsinstitut Senckenberg. 181, 89-93.
Mayr, 2007. The birds from the Paleocene fissure filling of Walbeck (Germany). Journal of Vertebrate Paleontology. 27(2), 394-408.

Tingmiatornis Bono, Clarke, Tarduno and Brinkman, 2016
T. arctica Bono, Clarke, Tarduno and Brinkman, 2016
Turonian, Late Cretaceous
Expedition Fiord, Nunavut, Canada
Holotype- (NUFV 1960) humerus (118.7 mm)
Paratypes- (NUFV 1838) proximal ulna
(UR 00.200) incomplete humerus
Diagnosis- (after Bono et al., 2016) differs from Ichthyornis in- more globose humeral head with significant posterior extent; narrow deltopectoral crest; more strongly developed secondary pneumotricipital fossa; bicipital crest more elongate, convex distally, and transitions smoothly into the humeral shaft distally; narrower, slightly cranially deflected deltopectoral crest that is significantly less than shaft diameter in dorsal extent.
Differs from Pasquiaornis tankei in- larger size; more globose dorsal condyle; weakly-projected olecranon process; smaller bicipital tubercle on ulna.
Comments- Bono et al. (2016) described Tingmiatornis as an ornithurine without a phylogenetic analysis.
Reference- Bono, Clarke, Tarduno and Brinkman, 2016. A large ornithurine bird (Tingmiatornis arctica) from the Turonian high arctic: Climatic and evolutionary implications. Scientific Reports. 6, 38876.

Graculavidae Furbringer, 1888 sensu Olson, 1985
Graculavinae Furbringer, 1888
References- Furbringer, 1888. Untersuchungen zur Morphologie und Systematik der Vogel, zugleich ein Beitrag zur Anatomie der Stiitz - und Bewegungsorgane. 2 volumes, 1751 pp.
Olson, 1985. The Fossil Record of Birds. in Famer, King and Parkes (eds.). Avian Biology. 8, 79-238.
Graculavus Marsh, 1872
= Limosavis Shufeldt, 1915
Diagnosis- (after Hope, 2002) humeral head small compared to living charadriiforms; dorsal tuber far from humeral head; dorsal tuber projected far from shaft; broad, flat surface between proximal tubers; capital groove ended posteriorly by shallow sulcus; transverse groove distal to humeral head; deep depressions for m. humerotriceps in pneumotricipital fossa; raised scar near base of ventral tubercle.
Comments- This was originally identified as a phalacrocoraciid ('graculid') by Marsh (1872), though Shufeldt (1915) thought it was a charadriine or scolopacine charadriiform ('limicoline'). Because of this, Shufeldt suggested the name Limosavis would be more appropriate, but this is not allowed by the ICZN. Contra Olson and Parris (1987), this was used in combination with velox by Shufeldt on page 76. Hope (2002) placed Graculavus close to or within Charadriiformes, though Mayr (2009) noted strong resemblance to presbyornithids. Indeed, Longrich et al. (2011) stated the large size of the presbyornithid "Styginetta lofgreni" (his Lancian Ornithurine C) "suggests that it may belong to Graculavus augustus."
Shufeldt (1915) incorrectly listed Graculavus idahensis as being named by Marsh in 1870, but Marsh actually named Graculus idahensis. The latter species is based on a proximal carpometacarpus (YPM 527) from the Pliocene of Idaho, and is currently known as Phalacrocorax idahensis (Marsh, 1870) Shufeldt, 1915 though no modern analysis has been attempted.
References- Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary formations of the United States. American Journal of Science, series 2. 49, 205-217.
Marsh, 1872. Preliminary description of Hesperornis regalis, with notices of four other new species of Cretaceous birds. American Journal of Science, series 3. 3, 360-365.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Olson and Parris, 1987. The Cretaceous Birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Mayr, 2009. Paleogene Fossil Birds. Springer Berlin Heidelberg. 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.
G. velox Marsh, 1872
= Limosavis velox (Marsh, 1872) Shufeldt, 1915
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Navesink or basal Hornerstown Formation, New Jersey, US
Holotype- (YPM 855) proximal humerus
Referred- ?(NJSM 11854) metacarpal II (51 mm) (Olson and Parris, 1987)
Diagnosis- (after Hope, 1999) 74% as large as G. augustus; area between ventral and dorsal tubercles relatively narrower and more concave.
Comments- Olson and Parris (1987) referred the partial carpometacarpus based on size only, so this assignment is questionable.
References- Marsh, 1872. Preliminary description of Hesperornis regalis, with notices of four other new species of Cretaceous birds. American Journal of Science, series 3. 3, 360-365.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Olson and Parris, 1987. The Cretaceous Birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
G. augustus Hope, 1999
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (AMNH 25223) proximal humerus
Diagnosis- (after Hope, 1999) 35% larger than G. velox; area between ventral and dorsal tubercles relatively wider and flatter.
Comments- The holotype was discovered in 1985.
Reference- Hope, 1999. A new species of Graculavus from the Cretaceous of Wyoming (Aves: Neornithes). 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, Washington, DC, June 1996. Smithsonian Contributions to Paleobiology. 89, 261-266.

Telmatornithidae Cracraft, 1972
Reference- Cracraft, 1972. A new Cretaceous charadriiform family. Auk. 89, 36-46.
Telmatornis Marsh, 1870
T. priscus Marsh, 1870
= Telmatornis affinis Marsh, 1870
?= Graculavus pumilis Marsh, 1872
Late Maastrichtian, Late Cretaceous
Navesink Formation, New Jersey, US
Holotype- (YPM 840) distal humerus
Referred- (YPM 845; holotype of Telmatornis affinis) distal humerus (Marsh, 1870)
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
basal Hornerstown Formation, New Jersey, US
(ANSP 15360) distal humerus (Olson and Parrish, 1987)
?(ANSP 15541) pedal phalanx II-1 (14.6 mm) (Olson and Parrish, 1987)
?(NJSM 11853) distal tarsometatarsus (Olson and Parrish, 1987)
?(NJSM 11900) proximal ulna (Olson and Parrish, 1987)
?(YPM 850; holotype of Graculavus pumilis) proximal humerus, partial carpometacarpus, forelimb fragments (Marsh, 1872)
Comments- Marsh (1870) believed Telmatornis was most similar to rallids and ardeids, though it has been most often compared to rallids or burhinids since. Cracraft (1972) was the first to favor a charadriiform identity and synonymized affinis and priscus as the only notable difference was the slightly larger size (~7-19%) and robusticity of priscus (contra Hope 2002, Shufeldt 1915 felt synonymy was possible but not determinable due to sample size). Olson and Parris (1987) also referred the holotypes of Graculavus pumilis and Palaeotringa vetus to this taxon, but Hope (2002) found vetus to be dissimilar to charadriiforms based on a new specimen from the Lance Formation. While Hope (2002) agrees pumilis is probably synonymous with priscus, the referral of the ulna, tarsometatarsus and phalanx are only based on size and similarity to burhinids. Hope (2002) found Telmatornis to share several characters with charadriiforms that are also found other taxa and are often developed to a lesser degree in crown members of the order.
The Graculavus pumilis holotype was found to be non-avian by Clarke (2002).
References- Marsh, 1870. Notice of some fossil birds from the Cretaceous and Tertiary formations of the United States. American Journal of Science, series 2. 49, 205-217.
Marsh, 1872. Preliminary description of Hesperornis regalis, with notices of four other new species of Cretaceous birds. American Journal of Science, series 3. 3, 360-365.
Cracraft, 1972. A new Cretaceous charadriiform family. Auk. 89, 36-46.
Olson and Parris, 1987. The Cretaceous Birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 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. University of California Press. 339-388.

undescribed panneognath (Hilton, Gohre, Embree and Stidham, 1999)
Campanian, Late Cretaceous
Chico Formation, California, US
Material- (UCMP 171185) ulna
Reference- Hilton, Gohre, Embree and Stidham, 1999. California's first fossil evidence of Cretaceous winged vertebrates. California Geology. 52(4), 4-10.

Vegaviiformes Worthy, Degrange, Handley and Lee, 2017
Vegaviidae Agnolín, Brissón Egli, Chatterjee, Garcia Marsà and Novas, 2017
Diagnosis- (after Agnolín et al., 2017) femoral obturator scars represented by two rugose impressions; femoral shaft strongly curved in lateral view; well-developed, deep, fibular trochlea with distinct proximal depression; patellar groove wide and flat; tibiotarsus with anterior cnemial crest proximally expanded; patellar crest absent; fibular crest well separated proximally from anterior cnemial crest.
Other diagnoses- Agnolín et al. also list four humeral characters supposedly shared between Vegavis and Australornis, but given Mayr et al.'s (2018) arguments against referring the latter to Vegaviidae, they aren't included here. They also list "Femur with: 5 - absent or distinct trochanteric fossa (ch. 186-1)" which not only includes two contradictory states, but is not the actual character 186 which scores for a pubic foot and is unknown in any vegaviid.
Comments- Agnolín et al. (2017) proposed Vegaviidae for Vegavis, Polarornis, Neogaeornis, the Paleocene Australornis and several unnamed specimens. Using a version of Worthy's basal avian analysis, Vegavis, Polarornis and Australornis were recovered as a clade sister to Anseriformes. Mayr et al. (2018) argued against assigning Neogaeornis, Australornis and most of the Tertiary unnamed specimens to the family based on qualitative data, correctly noting most characters shared with anseriforms are questionably present or also found in various neoavians which were not included in Worthy's matrix. Indeed, more recent analyses such as that of Field et al. (2020) with basal galloanserines such as Asteriornis and Conflicto have recovered Vegavis as sister to Aves or in a trichotomy with galloanserines and neoavians depending on search settings. Here vegaviids are placed in the latter position and Neogaeornis is argued to be a plausible member, but Tertiary specimens have not been evaluated.
References- Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.
Worthy, Degrange, Handley and Lee, 2017. The evolution of giant flightless birds and novel phylogenetic relationships for extinct fowl (Aves, Galloanseres). Royal Society Open Science. 4(10), 170975.
Mayr, De Pietri, Scofield and Worthy, 2018. On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 - Neornithine birds from the Upper Cretaceous of the Southern Hemisphere. Cretaceous Research. 86, 178-185.
Field, Benito, Chen, Jagt and Ksepka, 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature. 579, 397-401.

Maaqwi McLachlan, Kaiser and Longrich, 2017
M. cascadensis McLachlan, Kaiser and Longrich, 2017
Late Campanian, Late Cretaceous
Northumberland Formation of the Nanaimo Group, British Columbia, Canada
Holotype- (RBCM.EH2008.011.01120) (~1.4 kg) coracoid (53.2 mm), partial humerus (~93-103 mm), incomplete radius, incomplete ulna
Diagnosis- (after McLachlan et al., 2017) coracoid compact, polygonal in profile, with the omal portion approximately one third of the medial length; coracoid shaft a stout, flat bar; coracoid and humerus robust, highly pachyostotic.
Comments- Recovered in 2008 and initially described by Dyke et al. (2011) as Ornithurae, they stated it "superficially resemble the coracoid of the Paleogene basal palaeognath Lithornis in both its size and general shape, but with the shaft of the latter more slender." McLachlan et al. (2017) report further preparation of the coracoid "reveals further detail of its omal end, as well as adjacent forelimb bones previously hidden in the surrounding matrix." They used Clarke's avialan matrix to recover it as a vegaviid based on the short, broad coracoiod and noted pachyostosis also unites them.
References- 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, 1489-1496.
McLachlan, Kaiser and Longrich, 2017. Maaqwi cascadensis: A large, marine diving bird (Avialae: Ornithurae) from the Upper Cretaceous of British Columbia, Canada. PLoS ONE. 12(12), e0189473.

Vegavis Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005
Diagnosis- (after Clarke et al., 2016) deep, round ligament scar on posterior surface of proximal femur; lateral ridge on distal femoral shaft.
References- Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005. Definitive fossil evidence for the extant avian radiation in the Cretaceous. Nature. 433, 305-308.
Clarke, Chatterjee, Li, Riede, Agnolín, Goller, Isasi, Martinioni, Mussel and Novas, 2016. Fossil evidence of the avian vocal organ from the Mesozoic. Nature. 538, 502-505.
V. iaai Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005a
Late Maastrictian, Late Cretaceous
Sandwich Bluff Member of the Lopez de Bertodano Formation, Vega Island, Antarctica
Holotype- (MLP 93-I-3-1) two cervical vertebrae, five dorsal vertebrae, over six dorsal ribs, synsacrum (85 mm), scapula, coracoid (35.6 mm), humeri (one proximal; 124 mm), distal radius, ulna, pelvis, femora (~50 mm), tibiotarsus (124 mm), fibulae, partial tarsometatarsi
Referred- (MACN-PV 19.748; = MLP 93-I-3-2) (adult) pterygoid (9.8 mm), posterior mandible, ?hyoid, atlas (4.5 mm), axis (10.4 mm), third cervical vertebra (15.2 mm), fourth cervical vertebra (16.6 mm), fifth cervical vertebra (18.8 mm), twelfth cervical postzygapophysis, thirteenth cervical vertebra (12.2 mm), fourteenth cervical vertebra (14.9 mm), first dorsal vertebra (14.0 mm), second dorsal vertebra (11.9 mm), third dorsal vertebra (11.8 mm), fourth dorsal vertebra (10.0 mm), fifth dorsal vertebra (10 mm), partial dorsal ribs, three caudal vertebrae (5.8, 5.9, 6.2 mm), partial furcula, two sternal fragments, scapula (74.3 mm), coracoids (37.4 mm), humeri (~127.4 mm; one incomplete, one fragmentary), distal radius, distal ulna, scapholunare, pisiform, carpometacarpus (50.1 mm), phalanx I-1, phalanx II-1, phalanx II-2, phalanx III-1, femora (51.8 mm; one partial), patella, tibiotarsus (~112 mm), fibula (45.7 mm), five pedal phalanges, syrinx (Noriega and Tambussi, 1995; described in Clarke et al., 2016)
Late Campanian-Early Maastrictian, Late Cretaceous
Cape Lamb Member of the Snow Hill Formation, Vega Island, Antarctica
(MLP 98-I-10-51) proximal femur (~50 mm) (Acosta Hospitaleche and Gelfo, 2015)
Diagnosis- (from Clarke et al., 2005) low ridge on the medial edge of the proximal tibiotarsus (unknown in Polarornis).
(after West et al., 2019) (compared to V. sp. nov.) ~60% the size (also in Polarornis); femoral bone wall thinner (22% vs. 36%); proximoposterior scar with lip around most of circumference; posteroproximal fossa more laterally placed; distolateral crest better developed (taphonomic?); ectepicondyle grades smoothly into femoral shaft (also in Polarornis); fibular trochlea with less distinct proximal edge in posterior view (also in Polarornis); fibular trochlea more acute in distal view (also in Polarornis); larger medial condyle (96% of lateral condyle width vs. 56% in distal view; taphonomic?) (also in Polarornis).
Other diagnoses- Agnolín et al. (2017) suggested the femur was more gracile than Polarornis (most noticeable in side view for the distal shaft), but V. sp. nov. SDSM 78247 and Polarornis MLP 96-I-6-2 show intermediate conditions. Similarly, they suggest the anterior cnemial crest is anteroposteriorly deeper than in Polarornis, but Polarornis MLP 96-I-6-2 has a robust crest on its left knee and a slender one on its right, which combined with taphonomy suggests the character is unreliable.
Comments- Both the holotype and MACN-PV 19.748 were found associated in the same 1993 field season, although the first was described by Noriega and Tambussi as Presbyornithidae Genus and Species indeterminate, while the second was not described and merely called "another concretion with bird bones (MLP 93-I-3-2)." It was later discussed as presbyornithid Undetermined Species 3 by Hope (2002), who referred it to that family based on the proximally positioned humeral entepicondyle. Clarke et al. (2005a) redescribed MLP 93-I-3-1 based on new preparation and CT scanning, naming it Vegavis iaai and recovering it as an anseriform in a trichotomy with presbyornithids and anatids. Chatterjee et al. (2006) presented MACN-PV 19.748 as a "new and gracile species of a fossil loon Polarornis" in an SVP abstract, "considerably smaller and slender than its sympatric species Polarornis gregorii." Clarke et al. (2016) described this specimen as another Vegavis iaai, notable for preserving a syrinx.
Acosta Hospitaleche and Gelfo (2015) describe MLP 98-I-10-51 as Gaviiformes indet., but Agnolín et al. (2017) assigned it to Vegaviidae indet. as it "shares with Vegavis and Polarornis a nearly flat antitrochanteric fossa, anteroposteriorly compressed femoral shaft, and extensive obturator impressions." It is assigned to Vegavis iaai here based on its small size and the position of posteroproximal circular scar, which is placed more laterally than V. sp. nov..
References- Noriega and Tambussi, 1995. A Late Cretaceous Presbyornithidae (Aves: Anseriformes) from Vega Island, Antarctic Peninsula: Paleobiogeographic implications. Ameghiniana. 32, 57-61.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005 online. Vegavis iaai, Digital Morphology. http://digimorph.org/specimens/Vegavis_iaai/
Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005a. Definitive fossil evidence for the extant avian radiation in the Cretaceous. Nature. 433, 305-308.
Clarke, Tambussi, Noriega, Erickson and Ketcham, 2005b. New Cretaceous fossil evidence for the timing and pattern of avian diversification. Journal of Vertebrate Paleontology. 25(3), 46A.
Chatterjee, Martinioni, Novas, Mussel and Templin, 2006. A new fossil loon from the Late Cretaceous of Antarctica and early radiation of foot-propelled diving birds. Journal of Vertebrate Paleontology. 26(3), 49A.
Acosta Hospitaleche and Gelfo, 2015. New Antarctic findings of Upper Cretaceous and Lower Eocene loons (Aves: Gaviiformes). Annales de Paléontologie. 101(4), 315-324.
Clarke, Chatterjee, Li, Riede, Agnolín, Goller, Isasi, Martinioni, Mussel and Novas, 2016. Fossil evidence of the avian vocal organ from the Mesozoic. Nature. 538, 502-505.
Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.
Garcia Marsà, Agnolín and Novas, 2019 (online 2017). Bone microstructure of Vegavis iaai (Aves, Anseriformes) from the Upper Cretaceous of Vega Island, Antarctic peninsula. Historical Biology. 31(2), 163-167.
West, Torres, Case, Clarke, O'Connor and Lamanna, 2019. An avian femur from the Late Cretaceous of Vega Island, Antarctic peninsula: Removing the record of cursorial landbirds from the Mesozoic of Antarctica. PeerJ. 7:e7231.
V. sp. nov. (Case, Reguero, Martin and Cordes-Person, 2006)
Late Maastrictian, Late Cretaceous
Sandwich Bluff Member of the Lopez de Bertodano Formation, Vega Island, Antarctica
Material- (SDSM 78247) incomplete femur (~85 mm)
Diagnosis- (after West et al., 2019) (compared to V. iaai.) ~166% the size; femoral bone wall thicker (36% vs. 22%) (also in Polarornis); proximoposterior scar without lip around most of circumference; posteroproximal fossa more medially placed; distolateral crest less developed (taphonomic?); ectepicondyle forms corner with lateral edge of femoral shaft; fibular trochlea with abrupt proximal edge in posterior view; fibular trochlea more obtuse in distal view; smaller medial condyle (56% of lateral condyle width vs. 96% in distal view; taphonomic?).
Comments- Discovered in 2005, this specimen was said to resemble both cariamids and sagittariids by Case et al. (2006), with a preferred position close to cariamids. However, Cenizo (2012) criticized the characters used, and suggested the anatomy was more similar to foot-propelled diving birds- hesperornithines, podicipedids, gaviids and phalacrocoracoids. Agnolín et al. (2017; incorrectly stating it was a distal femur) suggested it shows "a combination of features shared with vegaviids, including anteriorly bowed shaft, medial distal condyle smaller than the lateral one, and trochlea fibularis transversely wide and laterally projected." This was confirmed by West et al. (2019) who redescribed the specimen as Vegavis sp. nov. based on the posteroproximal scar and laterodistal ridge which are lacking in Polarornis.
References- Case, Reguero, Martin and Cordes-Person, 2006. A cursorial bird from the Maastrictian of Antarctica. Journal of Vertebrate Paleontology. 26(3), 48A.
Cenizo, 2012. Review of the putative Phorusrhacidae from the Cretaceous and Paleogene of Antarctica: New records of ratites and pelagornithid birds. Polish Polar Research. 33(3), 225-244.
Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.
West, Torres, Case, Clarke, O'Connor and Lamanna, 2019. An avian femur from the Late Cretaceous of Vega Island, Antarctic peninsula: Removing the record of cursorial landbirds from the Mesozoic of Antarctica. PeerJ. 7:e7231.

Polarornis Chatterjee, 2002
= "Polarornis" Chatterjee, 1997
P. gregorii Chatterjee, 2002
Late Maastrictian, Late Cretaceous
Lopez de Bertodano Formation, Seymour Island, Antarctica
Holotype- (TTU P 9265) (~600 mm) partial skull (~180 mm), partial sixth cervical neural arch, seventh cervical vertebra (16 mm), eighth cervical vertebra, ninth cervical vertebra, sternal fragment, four partial sternal ribs, femora (one proximal; 62 mm), proximal tibiotarsus fused to proximal fibula
Referred- (MLP 96-I-6-2) incomplete femur, two proximal tibiotarsi, proximal fibula, pedal phalanx (Reguero et al., 2013; described in Acosta Hospitaleche and Gelfo, 2015)
Comments- This specimen was found in December 31 1983 and initially reported as an early loon by Chatterjee (1989, 1997), who unofficially named it "Polarornis" in the latter publication. It was officially named and described later by Chaterjee (2002). Both Olson (1992) and Hope (2002) believe the specimen to be a loon, though Martin (1998) and Feduccia (1999) were skeptical. The former thought it may be a penguin, while Feduccia also entertained the possibility it is a hesperornithine. It should be noted though that these opinions were all published prior to Polarornis' description, and that while Olson and Hoe had viewed the specimen, Martin and Feduccia's opinions were based on the schematic illustrations in Chatterjee's (1997) popular book. While Mayr says Polarornis "significantly differs from modern loons in several characters" and criticizes Chatterjee's misleading portrayal of the specimen's completeness, he does not actually suggest an alternative placement. Olson and Mayr suggested it could be synonymous with Neogaeornis, but this cannot be proven as Polarornis does not preserve the tarsometatarsus. Acosta Hospitaleche and Gelfo (2015) added Polarornis to Livezey and Zusi's large morphological matrix and found it it be a pan-gaviiform. Clarke et al. (2016) state the specimen "was extensively damaged during preparation, and the existence of the proposed braincase, quadrate, morphologies from most of the skull and tibial shaft cannot be confirmed" and figure it.
Reguero et al. (2013) figured the distal femur and two proximal tibiotarsi of MLP 96-I-6-2 as Polarornis gregorii, which was described by Acosta Hospitaleche and Gelfo (2015) as Polarornis sp. and referred to P. gregorii by Agnolín et al. (2017). The absent laterodistal femoral ridge suggests this is correct.
References- Chatterjee, 1989. The oldest Antarctic bird. Journal of Vertebrate Paleontology. 8(3), 11A.
Olson, 1992. Neogaeornis wetzeli Lambrecht, a Cretaceous loon from Chile (Aves, Gaviidae). Journal of Vertebrate Paleontology. 12(1), 122-124.
Chatterjee, 1997. The Rise of Birds. Baltimore: Johns Hopkins University Press. 312 pp.
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), 225-235.
Martin, 1998.
Feduccia, 1999. The Origin and Evolution of Birds. 2nd edition. Yale University Press. 466 pp.
Chatterjee, 2002. The morphology and systematics of Polarornis, a Cretaceous loon (Aves: Gaviidae) from Antarctica. In Zhou and Zhang (eds). Proceedings of the 5th Symposium of the Society of Avian Paleontology and Evolution, Beijing, 1-4 June 2000. Beijing: Science Press. 125-155.
Mayr, 2004. A partial skeleton of a new fossil loon (Aves, Gaviiformes) from the Early Oligocene of Germany with preserved stomach content. Journal of Ornithology. 45, 281-286.
Reguero, Tambussi, Coria and Marenssi, 2013. Late Cretaceous dinosaurs from the James Ross Basin, west Antarctica. Geological Society, London, Special Publications. 381, 99-116.
Acosta Hospitaleche and Gelfo, 2015. New Antarctic findings of Upper Cretaceous and Lower Eocene loons (Aves: Gaviiformes). Annales de Paléontologie. 101(4), 315-324.
Clarke, Chatterjee, Li, Riede, Agnolín, Goller, Isasi, Martinioni, Mussel and Novas, 2016. Fossil evidence of the avian vocal organ from the Mesozoic. Nature. 538, 502-505.
Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.

Neogaeornis Lambrecht 1929
N. wetzeli Lambrecht 1929
Maastrichtian, Late Cretaceous
Quiriquina Formation, Chile
Holotype- (GPMK 123) tarsometatarsus (~63 mm)
Referred- ? tarsometatarsus (Oliver Schneider, 1940)
Comments- The holotype was found in 1923-1924 and placed in Colymbo-Podicipediformes by Lambrecht, which containeed loons, grebes and taxa recognized today as basal hesperornithines. Brodkorb (1963) assigned Neogaeornis to Baptornithidae within Podicipediformes, the familial assignment being followed by Martin and Tate (1976), who placed baptornithids in Hesperornithiformes. They stated "the highly compressed tarsometatarsus with the outer trochlea slightly more distal than the middle one suggests affiliation with the Hesperornithiformes" while the "fact that the outer and middle trochleae are of about equal size supports an allocation to the Baptornithidae rather than the Hesperornithidae", though the latter is a symplesiomorphy. Olson (1992) redescribed the specimen, excluding it from Hesperornithiformes as it has hypotarsal ridges and proximal foramina. The latter are found in hesperornithiforms however, but hypotarsal ridges are unique to Aves. While admitting "it is conceivable that some other group entirely may have given rise to Neogaeornis during the Mesozoic", Olson finds the taxon more similar to loons than grebes and assigns it to Gaviidae, "greatly strengthened" by the then-undescribed Polarornis which he finds after personal examination to be "undeniably a loon referable to the modern family Gaviidae, and may possibly even be referable to Neogaeornis." Agnolín et al. (2017) referred Neogaeornis to their new family Vegaviidae based on having a tarsometatarsal shaft that is "notably transversely compressed with sharp lateral and medial edges" and "a posteriorly tilted trochlea of metatarsal II." Mayr et al. (2018) noted the latter "characterizes many diving taxa in Anseriformes, Procellariiformes, Gaviiformes, and Podicipediformes" but did not address the former. They correctly point out Neogaeornis' tarsometatarsus is less proximally expanded than probable vegaviid MLP 98-I-10-47, but claim it differs from Vegavis in having only two hypotarsal ridges instead of four. However, Neogaeornis' holotype is heavily worn proximally so that one of Vegavis' ridges would not be preserved so distally and a faint middle ridge is plausibly present. Finally, Mayr et al. dispute an identification as an anseriform vegaviid because that "the trochlea metatarsi IV extends distad of the trochlea metatarsi III in Neogaeornis is a trait not seen in any anseriform taxon and, similarly, the extremely proximally located and plantarly retracted trochlea metatarsi II is unlike in any anseriform bird; both, however, are podicipediform and gaviiform traits." But regardless of whether vegaviids are anseriforms, they are agreed to have evolved diving abilities convergently with loons and grebes, and the poorly preserved distal tarsometatarsi of probable vegaviids (e.g. MLP 98-1-10-76) are compatable with a morphology like Neogaeornis. Thus the taxon is here retained as a vegaviid pending better description and preservation of vegaviid tarsometatarsi.
References- Lambrecht, 1929. Neogaeornis wetzeli n. g. n. sp., der erste Kreidevogel der suedlichen Hemisphaere. Palaeontologische Zeitschrift. 11, 121-129.
Olver Schneider, 1940. La fauna fosil de Gualpen. Revista Chilena de Historia Natural Pura y Aplicada. 44, 49-54.
Brodkorb, 1963. Catalogue of fossil birds. Part 1 (Archaeopterygiformes through Ardeiformes). Bulletin of the Florida State Museum, Biological Sciences. 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.
Olson, 1992. Neogaeornis wetzeli Lambrecht, a Cretaceous loon from Chile (Aves, Gaviidae). Journal of Vertebrate Paleontology. 12(1), 122-124.
Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.
Mayr, De Pietri, Scofield and Worthy, 2018. On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 - Neornithine birds from the Upper Cretaceous of the Southern Hemisphere. Cretaceous Research. 86, 178-185.

Vegaviidae indet. (Acosta Hospitaleche and Gelfo, 2015)
Late Campanian-Early Maastrictian, Late Cretaceous
Cape Lamb Member of the Snow Hill Formation, Vega Island, Antarctica
Material- ?(MLP 98-I-10-27) incomplete tarsometatarsus
(MLP 98-I-10-47) incomplete tarsometatarsus
(MLP 98-I-10-49) distal tibiotarsus
(MLP 98-I-10-50) incomplete tarsometatarsus
(MLP 98-I-10-52) incomplete tarsometatarsus
(MLP 98-I-10-53) distal tibiotarsus
(MLP 98-I-10-54) incomplete tarsometatarsus
?(MLP 98-I-10-60) partial pedal phalanx
?(MLP 98-I-10-61) partial pedal phalanx
(MLP 98-I-10-76) incomplete tarsometatarsus
Comments- Acosta Hospitaleche and Gelfo (2015) refer this material to Gaviiformes indet., except MLP 98-I-10-27, 49 and 54 which they call cf. Gaviiformes. They state MLP 98-I-10-50, 52 and 76 are similar, so may be conspecific, and that MLP 98-I-10-27 and 54 are smaller. Agnolín et al. (2017) refer these to Vegaviidae indet., which is agreed upon here as they cannot be compared to Polarornis.
Reference- Acosta Hospitaleche and Gelfo, 2015. New Antarctic findings of Upper Cretaceous and Lower Eocene loons (Aves: Gaviiformes). Annales de Paléontologie. 101(4), 315-324.
Agnolín, Brissón Egli, Chatterjee, Garcia Marsà 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.

Galloanserae Sibley, Ahlquist and Monroe, 1988
Official Definition- crown(Gallus gallus + Anser anser) (Mindell, 2020; after Gauthier and de Queiroz, 2001; Registration Number 279)
= Galloanseres Weber, 1993
References- Sibley, Ahlquist and Monroe, 1988. A classification of the living birds of the world based on DNA-DNA hybridization studies. Auk. 105, 409-423.
Gauthier and de Queiroz, 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.
Mindell, 2020. Galloanserae C. Sibley, J. E. Ahlquist, and B. L. Monroe 1988 [D. P. Mindell], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1254-1257.

Pangalliformes Clarke, 2004
Definition- (Gallus gallus <- Anser anser) (Clarke, 2004)
Diagnosis- (after Clarke, 2004) asymmetrical development of the edges of the trochlea of metatarsal III.
References- Clarke, 2004. Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History. 286, 1-179.

Asteriornis Field, Benito, Chen, Jagt and Ksepka, 2020
A. maastrichtensis Field, Benito, Chen, Jagt and Ksepka, 2020
Late Maastrichtian, Late Cretaceous
Valkenburg Member of the Maastricht Formation, Belgium
Holotype- (NHMM 2013 008) (394 g) incomplete skull, mandibles (42.4, 35.3 mm), fragmentary humerus, distal radius, incomplete femora, incomplete tibiotarsi, incomplete tarsometatarsus
Diagnosis- (after Field et al., 2020) posteriorly pointed nasals that overlie the frontals and meet at the midline of the skull; slightly rounded, unhooked tip of the premaxilla.
Comments- Discovered in 2000, Field et al. (2020) described this and using Worthy's avian dataset recovered it as a pangalloanserine using parsimony or a pangalliform basal to Gallinuloides using tip-dated Bayesian analysis.
Reference- Field, Benito, Chen, Jagt and Ksepka, 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature. 579, 397-401.

Austinornis Clarke, 2004
Definition- (Austinornis lentus <- Gallus gallus, Crax rubra, Megapodius freycinet) (Clarke, 2004)
= "Austinornis" Clarke, 2002
A. lentus (Marsh, 1877) Clarke, 2004
Definition- (the species that includes YPM 1796)
= Graculavus lentus Marsh, 1877
= Ichthyornis lentus (Marsh, 1877) Marsh, 1880
= "Austinornis" lentus (Marsh, 1877) Clarke, 2002
Late Cretaceous
Austin Chalk, Texas, US
Holotype- (YPM 1796) distal tarsometatarsus
Comments- Discovered in 1876, Clarke (2004) referred this to Pangalliformes because the asymmetrical trochlea on metatarsal III (where the lateral edge projects more proximally) was stated to diagnose the gallinuloidid Paraortygoides and more crownward taxa by Mayr. Unfortunately the distal tarsometatarsus is unknown in Asteriornis, so it is unknown how far stemward the character exists (assuming Asteriornis is a pangalliform).
References- Marsh, 1877. New fossil vertebrates. American Journal of Science. 14, 249-256.
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.
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 possible pangalliform (Agnolín, Novas and Lio, 2006)
Late Turonian-Coniacian, Late Cretaceous
Portezuelo Member of Rio Neuquen Formation, Neuquen, Argentina
Material- (PVPH 237) proximal coracoid (~30 mm)
Comments- Agnolín et al. (2006) noted this was similar to galliforms in having a distinct scar for the insertion of the M. acrocoracohumeralis and a reduced procoracoid process. Within Galliformes, it was stated to resemble Quercymegapodiidae, Gallinuloididae, Paraortygidae and Megapodiidae in having a laterally expanded humeral articular surface and an ovoid and concave scapular cotyle.
Reference- Agnolín, Novas and Lio, 2006. Neornithine bird coracoid from the Upper Cretaceous of Patagonia. Ameghiniana. 43(1), 245-248.

Galliformes Temminck, 1820
Definition- (Megapodius freycinet, Crax rubra, Numida meleagris, Odontophorus gujanensis, Gallus gallus) (Field, Benito, Chen, Jagt and Ksepka, 2020)
Reference- Field, Benito, Chen, Jagt and Ksepka, 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature. 579, 397-401.

Anserimorphae Sibley, Ahlquist and Monroe, 1988
Definition- (Anser anser <- Gallus gallus) (Field, Benito, Chen, Jagt and Ksepka, 2020)
References- Sibley, Ahlquist and Monroe, 1988. A classification of the living birds of the world based on DNA-DNA hybridization studies. Auk. 105, 409-423.
Field, Benito, Chen, Jagt and Ksepka, 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature. 579, 397-401.

Kookne Novas, Agnolín, Rozadilla, Aranciaga-Rolando, Brissón-Eli, Motta, Cerroni, Ezcurra, Martinelli, D'Angelo, Álvarez-Herrera, Gentil, Bogan, Chimento, García-Marsà, Lo Coco, Miquel, Brito, Vera, Perez Loinaze, Fernandez and Salgado, 2019
K. yeutensis Novas, Agnolín, Rozadilla, Aranciaga-Rolando, Brissón-Eli, Motta, Cerroni, Ezcurra, Martinelli, D'Angelo, Álvarez-Herrera, Gentil, Bogan, Chimento, García-Marsà, Lo Coco, Miquel, Brito, Vera, Perez Loinaze, Fernandez and Salgado, 2019
Late Campanian-Early Maastrichtian, Late Cretaceous
Chorrillo Formation, Santa Cruz, Argentina
Holotype- (MPM 21550) proximal coracoid
Diagnosis- (after Novas et al., 2019) robust coracoidal shaft with well-defined and proximodistally extended procoracoid process; ligamentum coracoscapulare ventralis forming a well-defined scar, resulting in a notch that separates the scapular cotyla from the facies articularis humeralis; facies articularis humeralis ovoidal in shape, with its distal half more transversely expanded than the proximal half; cup-shaped impression for the acrocoracohumeral ligament, with thickened and well-defined margins.
Comments- Discovered between January and March 2019, Novas et al. assign this to Ornithurae. They believed it was most similar to anserimorphs, but differed from both presbyornithids and Conflicto.
Reference- Novas, Agnolín, Rozadilla, Aranciaga-Rolando, Brissón-Eli, Motta, Cerroni, Ezcurra, Martinelli, D'Angelo, Álvarez-Herrera, Gentil, Bogan, Chimento, García-Marsà, Lo Coco, Miquel, Brito, Vera, Perez Loinaze, Fernandez and Salgado, 2019. Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina. Revista del Museo Argentino de Ciencias Naturales. 21(2), 217-293.

Anatalavinae Olson, 1999
Comments- Olson (1999) proposed this subfamily within Anseranatidae, but more recent analyses place the Eocene 'Anatalavis' oxfordi outside crown Anseriformes, and thus not especially related to the living Anseranas. In particular, Tambussi et al. (2019) described the Paleocene Conflicto antarcticus which grouped with oxfordi as the basalmost clade of stem-anseriforms. Of the six recovered synapomorphies joining the species, the only one able to be evaluated in Anatalavis rex (deep olecranon fossa) is indeed present suggesting it may also be a member of this clade. The group should thus probably be evelated to family status as Anatalavidae Olson, 1999 given the undesirability of free-standing subfamilies.
An additional issue not tackled by Tambussi et al. concerns whether placing oxfordi within Anatalavis can be justified now that Conflicto is known. While Olson claimed rex and oxfordi were identical except for size (Conflicto is intermediate- at a distal humeral width of 17 mm vs. 13.2-13.6 and 22.3 mm respectively), Mlíkovský (2002) proposed oxfordi should be placed in a new genus Nettapterornis and listed four differentiating traits. Of these, Conflicto shares with oxfordi a ventral brachial fossa edge aligned with the shaft, a more transversely aligned dorsal condyle (primitive based on presbyornithids?; one of the differences said to be caused by "slightly different rotation of the specimens" in Olson's figure 8?), and an entepicondyle which does not project as far distally (derived?), but shares with rex a ventral condye which does not extend as far distally (derived?). There are also characters which rex and oxfordi share to the exclusion of Conflicto, such as a less ventrally extensive brachial fossa and a less flared entepicondyle (primitive?). Presbyornithids are polymorphic for both brachial fossa characters. As Conflicto shares one apparently derived character with each Anatalavis species, who in turn don't seem to share a unique derived character with each other, retaining oxfordi in Anatalavis seems problematic. Note even if Mourer-Chauviré (2004) is correct that all of Mlíkovský's proposed differences are caused by slightly different perspectives in Olson's photos, this still leaves no apparent derived characters shared by rex and oxfordi to the exclusion of Conflicto. While more circumstantial, the intermediate temporal placement of Conflicto would suggest a placement closer to oxfordi if anything. Thus Nettapterornis oxfordi is suggested as the best supported combination.
References- Olson, 1999. The anseriform relationships of Anatalavis Olson and Parris (Anseranatidae), with a new species from the Lower Eocene London Clay. Smithsonian Contributions to Paleobiology. 89, 231-243.
Mlíkovský, 2002. Cenozoic Birds of the World Part 1: Europe. Praha Ninox Press. 407 pp.
Mourer-Chauviré, 2004. Cenozoic Birds of the World, Part 1: Europe [Review]. The Auk. 121(2), 623-627.
Tambussi, Degrange, De Mendoza, Sferco and Santillana, 2019. A stem anseriform from the early Palaeocene of Antarctica provides new key evidence in the early evolution of waterfowl. Zoological Journal of the Linnean Society. 186(3), 673-700.

Anatalavis Olson and Parris, 1987
A. rex (Shufeldt, 1915) Olsen and Parris, 1987
= Telmatornis rex Shufeldt, 1915
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (YPM 902) incomplete humerus (~73 mm)
Paratype- (YPM 948) incomplete humerus (~76 mm)
Diagnosis- (after Olson, 1999) smaller and earlier than Nettapterornis [and Conflicto].
References- Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Cracraft, 1972. A new Cretaceous charadriiform family. Auk. 89, 36-46.
Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
Olson, 1999. The anseriform relationships of Anatalavis Olson and Parris (Anseranatidae), with a new species from the Lower Eocene London Clay. Smithsonian Contributions to Paleobiology. 89, 231-243.

Presbyornithidae Wetmore, 1926
= Torotigidae Brodkorb, 1963
References- Wetmore, 1926. Fossil birds from the Green River deposits of eastern Utah. Annals of the Carnegie Mueum. 16, 391-402.
Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. In Sibley (ed.). Proceedings of the XIII International Ornithological Congress. 50-70.

"Styginetta" Stidham, 2001
"S. lofgreni" Stidham, 2001
Late Maastrichtian-Early Danian, Late Cretaceous-Paleocene
Hell Creek Formation, Montana, US
Material- (MOR 2918) proximal coracoid (Longrich, Tokaryk and Field, 2011)
(UCMP 130710; intended paratype) proximal scapula (Bryant, 1989) 7.0
(UCMP 130711; intended paratype) proximal scapula (Bryant, 1989) ~7
(UCMP 175251; intended paratype) proximal coracoid (Stidham, 2001) ~11.4
Early Danian, Paleocene
Hell Creek Formation, Montana, US
(RAM 6707; intended holotype) incomplete coracoid (Stidham, 2001) 9.7
(RAM 6708; intended paratype) anterior sternum (Stidham, 2001)
(UCMP 187208; intended paratype) proximal coracoid (Stidham, 2001) ~12.3
Late Maastrichtian, Late Cretaceous
Hell Creek Formation, South Dakota, US
(SDSM 64281A) proximal coracoid (Longrich, Tokaryk and Field, 2011)
(SDSM 64281B) proximal coracoid (Longrich, Tokaryk and Field, 2011)
Early Danian, Paleocene
Tullock Member of the Fort Union Formation, Montana, US
(UCMP 130713; intended paratype) proximal coracoid (Bryant, 1989) ~9.7
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
(AMNH 22602) anterior sternum (Hope, 2002)
(YPM PU 17020) proximal coracoid (Longrich, Tokaryk and Field, 2011)
Late Maastrichtian, Late Cretaceous
Hell Creek or Lance Formation, US
(BHI coll.) (Longrich, 2009)
Diagnosis- (after Longrich, Tokaryk and Field, 2011) very deep acrocoracoid fossa; acrocoracoid ending in a massive knob; deep and large scapular facet.
Comments- Discovered in 1976 and June 14 1983 respectively, UCMP 130710 and 130711 were first listed as scapula fragments of Aves by Bryant (1989). UCMP 130713 was found in 1980 and listed by Bryant as being an avian coracoid fragment. UCMP 175251 was found in 1992, and 187208 in July 20 1987, both identified as anseriforms by Stidham between 1999-2001. Note Longrich et al. (2011) incorrectly claim UCMP 187208 is from the Paleocene Fort Union Formation, but its locality is Lakeside UCMP V84024 which is the Cretaceous Hell Creek Formation. Stidham (2001) describe these specimens in addition to coracoid RAM 6707 and sternum 6708 in his thesis as a new genus and species of presbyornithid, whose name was published in Molina-Perez and Larramendi's (2019) book as a nomen nudum for RAM 6707.
YPM PU 17020 was found in 1893 and initially catalogued as Cimolopteryx sp.. Longrich et al. describe UCMP 175251 and 187208, in addition to MOR 2918, SDSM 64281A and B and YPM PU 17020, as Lancian Ornithurine C and state "the large size of the bird suggests that it may belong to Graculavus augustus." This is probably what Longrich (2009) listed as "large ornithurine" in their Table 1, based on "uncatalogued specimens at the Black Hills Institute and South Dakota School of Mines."
AMNH 22602 was found in 1981 and described as presbyornithid Undetermined Species 2 by Hope (2002). It seems similar to RAM 6708 in morphology and size, so is referred to "Styginetta lofgreni" here.
References- Bryant, 1989. Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeastern Montana. University of California Publications in Geological Sciences. 134, 107 pp.
Stidham, 2001. The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes). PhD Thesis, University of California. 257 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. 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.
Stidham, 2009. Latest Cretaceous presbyornithids (Anseriformes) from North America. Journal of Vertebrate Paleontology. 29(3), 186A.
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.
Molina-Perez and Larramendi, 2019. Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Princeton University Press. 288 pp.
"S." sp. nov. (Shefeldt, 1915)
Late Maastrichtian-Early Danian, Late Cretaceous-Paleocene
Hell Creek Formation, Montana, US
(ANSP 15866) proximal coracoid (Hope, 2002)
Early Danian, Paleocene
Hell Creek Formation, Montana, US
(AMNH 24322) anterior sternum (Stidham, 2001)
(UCMP 187209) proximal scapula (Stidham, 2001) 5.2
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (AMNH 21929) proximal scapula (Hope, 2002) 4.7
(AMNH 22603) proximal scapula (Hope, 2002) 6.3
(UCMP 53964) distal carpometacarpus (Brodkorb, 1963)
(UCMP 53969) quadrate (6.0 mm) (Brodkorb, 1963)
(UCMP 187210) proximal scapula (Stidham, 2001) 6.3
(UCMP 187211) (juvenile) proximal scapula (Stidham, 2001) 3.5
(YPM 868) proximal scapula (Shufeldt, 1915) ~4.7
Comments- Stidham (2001) described sternum AMNH 24322 and three scapulae (UCMP 187209, 187210 and 187211) as a new species of his unofficial genus "Styginetta" based on morphological similarity but smaller size. It was not named because no coracoids were identified to compare to the proposed holotype of "S. lofgreni" (although see below).
Distal carpometacarpus UCMP 53964 was found in 1958 and referred to Cimolopteryx rara by Brodkorb (1963) based on supposed resemblences to Recurvirostra. Hope (2002) felt it was similar to Telmatornis priscus based on unspecified characters, but this is based on the Graculavis pumilis type that is only questionably referred as it is not comparable to the Telmatornis type. Hope kept the referral to C. rara provisional due to the cooccurance of her Charadriiformes Undetermined Species 1, which corresponds to Longrich's Lancian Ornithurine E. Perhaps more convincingly, Stidham (2001) argued that the specimen was nearly identical to Presbyornis and assigned it to his small unnamed species of "Styginetta" based on size and provenence.
Scapula AMNH 22603 was found in 1960 and described as presbyornithid Undetermined Species 4 by Hope (2002). Its glenoid is equal in length to UCMP 187210, so it is referred to Stidham's small species here. Hope mentions ANSP 15866 as "a coracoid of an undescribed presbyornithid about one-third smaller than P. pervetus" that apposes well to it, so this also may be referrable to this species and allow comparison with "S. lofgreni." YPM 868 was found in April 1890 and referred to Cimolopteryx rara by Shufeldt (1915). It was said by Hope to "probably be the "other material" mentioned by Marsh (1892) in his description" of the taxon, but that this morphology "would not appose well to the coracoid of C. rara." Hope describes a near identical scapula AMNH 21929 found in July 1982 and refers both to her presbyornithid Undetermined Species 3. As no differences between Species 3 and 4 are noted by Hope except for size and Species 3 is still larger than juvenile UCMP 187211 referred to "Styginetta" sp. nov. by Stidham, it is also provisionally considered conspecific here.
Discovered in 1958, Brodkorb (1963) referred quadrate UCMP 53969 to Cimolopteryx rara within Charadriiformes based on supposed resemblence to recurvirostrids in both. Hope (2002) noted it was not a charadriiform based on several characters and described it as Aves Undetermined Species 2, most similar to plesiomorphic neognaths. Elzanowski and Stidham (2011) described the specimen in depth as a "galloanserine and most probably to a stemgroup anseriform (near the split with the galliforms)" "most similar to that of Presbyornis in the presence of a large basiorbital foramen, the absence of any dorsal expansions of the pars quadratojugalis, a wide intercapitular incisure, the otic capitulum larger than the squamosal one (although it is much larger in UCMP 53969, but only slightly larger in Presbyornis), and a wide intercondylar incisure (that also remains relatively wide in the anhimids)." As it is about half the size of Presbyornis, it may be referrable to Stidham's "Styginetta" sp. nov..
References- Marsh, 1892. Notes on Mesozoic vertebrate fossils. American Journal of Science. 44, 170-176.
Shufeldt, 1915. Fossil birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences. 19, 1-110.
Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. International Ornithological Congress, Proceedings. 19, 55-70.
Stidham, 2001. The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes). PhD Thesis, University of California. 257 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Stidham, 2009. Latest Cretaceous presbyornithids (Anseriformes) from North America. Journal of Vertebrate Paleontology. 29(3), 186A.
Elzanowki and Stidham, 2011. A galloanserine quadrate from the Late Cretaceous Lance Formation of Wyoming. The Auk. 128(1), 138-145.

Teviornis Kurochkin, Dyke and Karhu, 2002
T. gobiensis Kurochkin, Dyke and Karhu, 2002
Maastrichtian, Late Cretaceous
Gurilin Tsav, Nemegt Formation, Mongolia
Holotype- (PIN 4499-1) distal humerus, scapholunare, pisiform, carpometacarpus (65 mm), phalanx II-1 (30.8 mm), phalanx III-1 (13.9 mm), material (lost)
Diagnosis- (after Kurochkin et al., 2002) dorsal supracondylar tuber of humerus extended far proximally; distal articular facet of metacarpal II widened distally; ventral portion of metacarpal II distal articular facet elevated in the direction of the tubercle for the insertion of m. abductor digiti majoris; distal articular facet of metacarpal III divided by a craniocaudal groove into two distinct facets.
Other diagnoses- De Pietri et al. (2016) found that one character used bu Kurochkin et al. (2002) in their diagnosis (infratrochlear fossa of carpometacarpus stretched markedly craniocaudally) is also present in the presbyornithid Wilaru. They similarly noted another proposed character (proximal portion metacarpal III widened both dorsoventrally and craniocaudally with respect to its distal portion) is present in anhimids and other anseriforms, so may be a symplesiomorphy compared to Presbyornis.
Comments- Discovered in 1987, but not described until Kurochkin et al. (2002). They state "notes from members of the original 1987 PIN field team indicated that more remains of this single specimen were initially collected from this locality. This material was subsequently damaged and lost." While Clarke and Norell (2004) questioned the presbyornithid and anseriform identity of Teviornis based on broader distributions of the characters proposed by Kurochkin et al., De Pietri et al. (2016) described additional characters which in combination are only known in presbyornithids.
References- Kurochkin, Dyke and Karhu, 2002. A new presbyornithid bird (Aves, Anseriformes) from the Late Cretaceous of Southern Mongolia. American Museum Novitates. 3386, 11 pp.
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.
De Pietri, Scofield, Zelenkov, Boles and Worthy, 2016. The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: The youngest record of Presbyornithidae. Royal Society Open Science. 3, 150635.

Torotix Brodkorb, 1963
T. clemensi Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53958) distal humerus
Diagnosis- (after Parris and Hope, 2002) differs from Novacaesareala in having a narrow flexor process.
Comments- Assigned to Phoenicopteriformes by Brodkorb (1963), it was later placed in Charadriiformes (Olson and Feduccia, 1980; Olson, 1985), and most recently to Pelecaniformes by Hope (2002). The latter was based on several characters- ventral rim of brachial fossa very narrow; attachment for ventral collateral ligament small; flexor process broad and very short; sites for M. flexor carpi ulnaris and pronator profundus oriented ventrally; ventral epicondyle extended only slightly ventrally. However, Parris and Hope (2002) state the flexor process is narrow, unlike pelecaniforms and Novacaesareala. Stidham (2001) stated most features fell within the range of Presbyornis and even posited synonymy of the genera, though he noted the brachial fossa is deeper than P. pervetus and the anterior articular ligament attachment faces more distally.
Hope (2002) states Brodkorb wrote "Same species as Humerus?" on a note in the UCMP collections for two cervical vertebral fragments (UCMP 53960), which were catalogued as Torotix. This referral was never published by Brodkorb however, and the specimen is currently catalogued as Aves indet. at the UCMP and on this website.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. In Sibley (ed.). Proceedings of the XIII International Ornithological Congress. 50-70.
Olson and Feduccia, 1980. Presbyornis and the origin of the Anseriformes (Aves, Charadrimorphae). Smithsonian Contribs. Zool. 323, 24 pp.
Olson, 1985. The fossil record of birds. 79-239. in Farner, King and Parkes (eds.). Avian Biology. vol VIII. Academic Press, New York.
Stidham, 2001. The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes). PhD Thesis, University of California. 257 pp.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
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.

Anseriformes Wagler, 1831
Definition- crown(Anser anser <- Gallus gallus, Passer domesticus) (Martyniuk, 2012)
Other definitions- (Anhima cornuta + Anseranas semipalmata + Anser anser) (Field, Benito, Chen, Jagt and Ksepka, 2020)
= Anseriformes sensu Field et al., 2020
Definition- (Anhima cornuta + Anseranas semipalmata + Anser anser)

Panneoaves Gauthier and de Queiroz, 2001
Definition- (Passer domesticus <- Gallus gallus, Anser anser) (Gauthier and de Queiroz, 2001)
= Neoaves sensu Sereno, 1998
Definition- (Passer domesticus <- Anas platyrhynchos) (modified)

Neoaves Sibley, Ahlquist and Monroe, 1988
Official Definition- crown (Passer domesticus <- Gallus gallus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022)
Other definitions- (Passer domesticus <- Anas platyrhynchos) (modified from Sereno, 1998)
crown (Passer domesticus <- Gallus gallus, Anser anser) (Gauthier and de Queiroz, 2001)
(Phoenicopterus ruber + Columba oenas + Otis tarda + Musophaga violacea + Caprimulgus europaeus + Opisthocomus hoazin + Grus grus + Charadrius hiaticula + Phaethon aethereus + Procellaria aequinoctialis + Passer domesticus) (Field, Benito, Chen, Jagt and Ksepka, 2020)
= Coronaves Fain and Houde, 2004
= Metaves Fain and Houde, 2004
= Insolitaves Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleson, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
= Litoritelluraves Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleson, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
= Columbea Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014
= Cursorimorphae Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014
= Passerea Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014
= Neoaves sensu Field, Benito, Chen, Jagt and Ksepka, 2020
Definition- (Phoenicopterus ruber + Columba oenas + Otis tarda + Musophaga violacea + Caprimulgus europaeus + Opisthocomus hoazin + Grus grus + Charadrius hiaticula + Phaethon aethereus + Procellaria aequinoctialis + Passer domesticus)
References- Sibley, Ahlquist and Monroe, 1988. A classification of the living birds of the world based on DNA-DNA hybridization studies. The Auk. 105(3), 409-423.
Sereno, 1998. A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen. 210(1), 41-83.
Gauthier and de Queiroz, 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.
Fain and Houde, 2004. Parallel radiations in the primary clades of birds. Evolution. 58(11), 2558-2573.
Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleson, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014. Whole-genome analyses resolve early branches in the tree of life of modern birds. Science. 346(6215), 1320-1331.
Field, Benito, Chen, Jagt and Ksepka, 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature. 579, 397-401.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Caprimulgimorphae Cracraft, 2013
Official Definition- (Caprimulgus europaeus, Steatornis caripensis, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus, Apus apus <- Phoenicopterus ruber, Columba oenas, Otis tarda, Musophaga violacea, Opisthocomus hoazin, Grus grus, Charadrius hiaticula, Phaethon aethereus, Procellaria aequinoctialis, Vultur gryphus) (Chen and Field, 2020; Registration Number 383)
References- Cracraft, 2013. Avian higher-level relationships and classification: Nonpasseriforms. In Dickinson and Remsen (eds.). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition, vol. 1: Non-passerines. Aves Press. xxi-xliii.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Strisores Cabanis, 1847
Official Definition- crown (Caprimulgus europaeus + Steatornis caripensis + Nyctibius grandis + Podargus strigoides + Aegotheles cristatus + Apus apus) (Chen and Field, 2020; Registration Number 384)
= Cypselomorphae Huxley, 1867
Official Definition- (Caprimulgus europaeus, Nyctibius grandis, Aegotheles cristatus, Apus apus <- Steatornis caripensis, Podargus strigoides) (Chen and Field, 2020; Registration Number 386)
= Caprimulgi Ridgway, 1881
Official Definition- (Caprimulgus europaeus, Nyctibius grandis <- Steatornis caripensis, Podargus strigoides, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 387)
= Podargocypseli Mayr, 2010
Official Definition- crown (Caprimulgus europaeus, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus, Apus apus <- Steatornis caripensis) (Chen and Field, 2020; Registration Number 385)
References- Cabanis, 1847. Ornithologische Notizen II. Archiv für Naturgeschichte. 13, 308-352.
Huxley, 1867. On the classification of birds: And on the taxonomic value of the modifications of certain of the cranial bones observable in that class. Proceedings of the Zoological Society of London. 35, 415-472.
Ridgway, 1881. A revised catalog of the birds ascertained to occur in Illinois. Bulletin of the Illinois State Laboratory of Natural History. 1(4), 163-208.
Mayr, 2010 (online 2009). Phylogenetic relationships of the paraphyletic "caprimulgiform" birds (nightjars and allies). Journal of Zoological Systematics and Evolutionary Research. 48(2), 126-137.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Caprimulgiformes Shufeldt, 1904
Official Definition- (Caprimulgus europaeus <- Steatornis caripensis, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 388)
Comments- Chen and Field (2020) state "Caprimulgiformes is typically attributed to RIDGWAY (1881), likely because he was the first to use the genus Caprimulgus as the basis for an ordinal-level name, which he spelled Caprimulgi. However, under the PhyloCode, names that have been subjected to such standardization should be attributed to the author who introduced the new spelling ... (Notes 9.15A.4 and 19.5.1). The oldest use of the spelling Caprimulgiformes that we have been able to locate was by SHUFELDT (1904)."
References- Shufeldt, 1904. An arrangement of the families and the higher groups of birds. The American Naturalist. 38(455/456), 833-857.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Caprimulgidae Vigors, 1825
Official Definition- crown (Eurostopodus mystacalis + Lyncornis macrotis + Caprimulgus europaeus) (Chen and Field, 2020; Registration Number 389)
References- Vigors, 1825. Observations on the natural affinities that connect the orders and families of birds. Transactions of the Linnean Society of London. 14, 395-517.
Ridgway, 1881. A revised catalog of the birds ascertained to occur in Illinois. Bulletin of the Illinois State Laboratory of Natural History. 1(4), 163-208.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Vanescaves Chen, White, Benson, Braun and Field, 2019
Official Definition- crown (Steatornis caripensis, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus, Apus apus <- Caprimulgus europaeus) (Chen and Field, 2020; Registration Number 390)
References- Chen, White, Benson, Braun and Field, 2019. Total-evidence framework reveals complex morphological evolution in nightbirds (Strisores). Diversity. 11(9), 143.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Sedentaves Chen and Field, 2020
Official Definition- crown (Steatornis caripensis, Nyctibius grandis <- Caprimulgus europaeus, Podargus strigoides, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 422)
Reference- Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Steatornithiformes Mayr, 2010
Official Definition- (Steatornis caripensis <- Caprimulgus europaeus, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 391)
References- Mayr, 2010 (online 2009). Phylogenetic relationships of the paraphyletic "caprimulgiform" birds (nightjars and allies). Journal of Zoological Systematics and Evolutionary Research. 48(2), 126-137.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Nyctibiiformes Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- (Nyctibius grandis <- Caprimulgus europaeus, Steatornis caripensis, Podargus strigoides, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 393)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Nyctibiidae Chenu and des Murs, 1851 sensu Sharpe, 1891
Official Definition- crown (Phyllaemulor bracteatus + Nyctibius grandis + Nyctibius griseus) (Chen and Field, 2020; Registration Number 394)
Comments- Chen and Field (2020) note that "Under the International Code of Zoological Nomenclature (ICZN, 1999), this name is attributed to CHENU & DES MURS (1851) (who coined it with the spelling Nyctibiines). As noted under comments on Caprimulgiformes, however, the PhyloCode treats attribution of names that have been amended to a standardized suffix under a rank-based code differently. The oldest use of the spelling Nyctibiidae that we have been able to locate was by SHARPE (1891)..."
References- Chenu and des Murs, 1851. Encyclopédie d’histoire naturelle: oiseaux deuxième partie. Marescq et Compagnie and Gustave Harvard. 311 pp.
Sharpe, 1891. A Review of Recent Attempts to Classify Birds. Budapest, Office of the Congress. 90 pp.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Letornithes Chen and Field, 2020
Official Definition- crown (Podargus strigoides, Aegotheles cristatus, Apus apus <- Caprimulgus europaeus, Steatornis caripensis, Nyctibius grandis) (Chen and Field, 2020; Registration Number 423)
Reference- Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Podargiformes Mathews, 1919
Official Definition- (Podargus strigoides <- Caprimulgus europaeus, Steatornis caripensis, Nyctibius grandis, Aegotheles cristatus, Apus apus) (Chen and Field, 2020; Registration Number 395)
Comments- The year of Mathews' work is given as 1918 by Chen and Field (2020), but is listed as 1918-1919 in the publication itself.
References- Mathews, 1919. The Birds of Australia Volume VII. Witherby & Co. 499 pp.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Podargidae Bonaparte, 1838 sensu Sclater, 1880
Official Definition- crown (Rigidipenna inexpectata + Podargus strigoides + Batrachostomus auritus) (Chen and Field, 2020; Registration Number 396)
Comments- Chen and Field (2020) note "Under the ICZN’s Principle of Coordination (Article 36), this name is attributed to BONAPARTE (1838) (who coined Podarginae at the rank of subfamily). However, the PhyloCode ignores the ICZN ’s Principle of Coordination in determining nominal authorship (Note 9.15A.3). The oldest use of Podargidae that we have been able to locate was by SCLATER (1880)..."
References- Bonaparte, 1838. Synopsis vertebratorum systematis. Nuovi Annali delle Scienze Naturali. Bologna. 1, 105-133.
Sclater, 1880. Remarks on the present state of the Systema Avium. Ibis. 22(4), 399-411.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Daedalornithes Sangster, 2005
Official Definition- crown (Aegotheles cristatus + Apus apus) (Sangster, 2020; Registration Number 287)
References- Sangster, 2005. A name for the clade formed by owlet-nightjars, swifts and hummingbirds (Aves). Zootaxa. 799(1), 1-6.
Sangster, 2020. Daedalornithes G. Sangster 2005 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1288-1291.

Aegotheliformes Worthy, Tennyson, Jones, McNamara and Douglas, 2007
Official Definition- (Aegotheles cristatus <- Caprimulgus europaeus, Steatornis caripensis, Nyctibius grandis, Podargus strigoides, Apus apus) (Chen and Field, 2020; Registration Number 397)
References- Worthy, Tennyson, Jones, McNamara and Douglas, 2007. Miocene waterfowl and other birds from central Otago, New Zealand. Journal of Systematic Palaeontology. 5(1), 1-39.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Pan-Apodiformes Ksepka, Clarke, Nesbitt, Kulp and Grande, 2013
Official Definition- (Apus apus <- Caprimulgus europaeus, Steatornis caripensis, Nyctibius grandis, Podargus strigoides, Aegotheles cristatus) (Chen and Field, 2020; Registration Number 399)
References- Ksepka, Clarke, Nesbitt, Kulp and Grande, 2013. Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes). Proceedings of the Royal Society B: Biological Sciences. 280(1761), 20130580.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Apodiformes Peters, 1940
Official Definition- crown (Phaethornis griseogularis + Apus apus) (Sangster, 2020; Registration Number 288)
References- Peters, 1940. Check-list of Birds of the World, Volume IV. Harvard University Press. 291 pp.
Sangster, 2020. Apodiformes J. L. Peters 1940 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1292-1296.

Apodi Peters, 1940
Official Definition- crown (Hemiprocne longipennis + Apus apus) (Chen and Field, 2020; Registration Number 400)
References- Peters, 1940. Check-list of Birds of the World, Volume IV. Harvard University Press. 291 pp.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Apodidae Olphe-Galliard, 1887
Official Definition- crown (Cypseloides fumigatus + Streptoprocne zonaris + Collocalia esculenta + Chaetura pelagica + Apus apus) (Chen and Field, 2020; Registration Number 402)
References- Olphe-Galliard, 1887. Contributions à la faune ornithologique de l’Europe occidentale Volume 22. L. Lasserre. 106 pp.
Chen and Field, 2020. Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature. Vertebrate Zoology. 70(4), 571-585.

Cuculiformes

Cuculidae Leach, 1820
Official Definition- crown (Carpococcyx radiceus + Centropus senegalensis + Crotophaga ani + Cuculus canorus + Neomorphus geoffroyi + Piaya cayana) (Sangster, 2020; Registration Number 280)
References- Leach, 1820. Eleventh room. In Leach (ed.). Synopsis of the Contents of the British Museum, Seventeenth Edition. Rich and Arthur Taylor. 65-70.
Sangster, 2020. Cuculidae W. E. Leach 1820 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1258-1263.

Musophagotides Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- crown (Otis tarda, Musophaga violacea <- Grus grus, Mesitornis variegatus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 703)
Reference- Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Musophagiformes

Otidiformes

Columbimorphae Cracraft, 2013
Official Definition- crown (Columba oenas + Mesitornis variegatus + Pterocles alchata) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 701)
References- Cracraft, 2013. Avian higher-level relationships and classification: Nonpasseriforms. In Dickinson and Remsen (eds.). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition, vol. 1: Non-passerines. Aves Press. xxi-xliii.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Columbiformes

Pteroclimesites Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- crown (Mesitornis variegatus + Pterocles alchata) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 702)
Reference- Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Mesitornithiformes

Pterocliformes

Gruiformes Bonaparte, 1854

Grues Bonaparte, 1854

Lamarqueavis Agnolín, 2010
Diagnosis- (after Agnolín, 2010) distally extended procoracoid process; distally straight glenoid; glenoid transversely elongate >120% of proximodistal height.
(proposed) distally placed supracoracoid foramen.
Comments- While Agnolín (2010) assigned this to Cimolopterygidae, Mohr et al. (2021) critique his proposed cimolopterygid characters. They correctly note the distally extended procoracoid process and distally placed supracoracoid foramen are only present in Lamarqueavis and the Irvine bird. Additionally, the laterally angled glenoid is only present in Cimolopteryx rara and Lamarqueavisassuming Longrich et al.'s (2011) photos are taken orthogonally, and the supracoracoid foramen is only enlarged in the Irvine bird. Mayr (2016) suggested it "more closely resembles that of some gruiform birds, such as trumpeters (Psophiidae) and the early Cenozoic Messelornithidae, although the fossil is too fragmentary for a well-founded classification."
References- Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
Mayr, 2016. Avian Evolution: The Fossil Record of Birds and its Paleobiological Significance. John Wiley & Sons, Ltd. 306 pp.
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.
L. australis Agnolín, 2010
Maastrichtian, Late Cretaceous
Allen Formation, Río Negro, Argentina
Holotype- (MML 207) partial coracoid
Diagnosis- (after Agnolín, 2010) medially convex procoracoid process (unknown in the Irvine bird); glenoid strongly tilted laterally (Agnolín et al. mistakenly wrote "medially"; also in Cimolopteryx rara).
Other diagnoses- Agnolín (2010) also listed a distally extended procoracoid and distally placed supracorfacoid foramen, but these are also present in the Irvine bird L. sp. nov..
Reference- Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.
L. sp. nov. (Longrich, 2009)
Late Campanian, Late Cretaceous
Dinosaur Park Formation, Alberta, Canada
Material- (UALVP 47943; Ornithurine B; Irvine bird) proximal coracoid
?...(UALVP 47944) anterior sternum
?(UALVP coll.) sternal fragment
Diagnosis- (after Longrich, 2009) circular scapular cotyle; large, ventrally placed supracoracoideus nerve foramen; longitudinal ridge on medial surface of coracoid below acrocoracoid process; very small size. Agnolín (2010) considered this to be a species of his new supposed cimolopterygid genus Lamarqueavis, and his characters appear to be valid.
Comments- Longrich (2009) called this Ornithurine B or the Irvine bird. He assigned it to his Ornithurae sensu Gauthier and de Quieroz based on an anteriorly placed scapular facet.
References- Longrich, 2009. An ornithurine-dominated avifauna from the Belly River Group (Campanian, Upper Cretaceous) of Alberta, Canada. Cretaceous Research. 30, 161-177.
Agnolín, 2010. An avian coracoid from the Upper Cretaceous of Patagonia, Argentina. Studia Geologica Salmanticensia. 46(2), 99-119.

Aequorlitornithes Prum, Berv, Dornburg, Field, Townsend, Lemmon and Lemmon, 2015

unnamed possible aeqourlitornithine (Powell, 1987)
Campanian-Maastrichtian, Late Cretaceous
Allen Formation, Río Negro, Argentina
Material- (PVL 4730) proximal tibiotarsus
Comments- This was first listed by Powell (1987) as Aves, then figured and identified as an ornithurine by Chiappe (1996). Chiappe noted while it was found in the same quarry as Limenavis, it was much smaller so unlikely to be the same taxon. Hope (2002) referred it to charadriiforms based on cnemial crest morphology, though noted this was symplesiomorphic compared to loons, procellariiforms and grebes. Thus the cnemial crest characters might be primitive for Aequorlitornithes.
References- Powell, 1987. Hallazgo de un dinosaurio hadrosaurido (Ornithischia: Ornithopoda) en la Formación Allen (Cretácico Superior) de Salitral Moreno, Prov. de Río Negro, Argentina. Congreso Geológico Argentino. 10(3), 149-152.
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.
Chiappe, 1996. Early avian evolution in the southern hemisphere: Fossil record of birds in the Mesozoic of Gondwana. Memoirs of the Queensland Museum. 39, 533-556.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Mirandornithes Sangster, 2005
Official Definition- crown (Phoenicopterus chilensis + Podiceps auritus) (Sangster, 2020; Registration Number 281)
Other definitions- (Phoenicopterus ruber + Podiceps cristatus) (Sangster, 2005)
= Mirandornithes sensu Sangster, 2005
Definition- (Phoenicopterus ruber + Podiceps cristatus)
References- Sangster, 2005. A name for the flamingo-grebe clade. Ibis. 147(3), 612-615.
Sangster, 2020. Mirandornithes G. Sangster 2005 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1264-1267.

Podicepediformes

Phoenicopteriformes

Charadriiformes Garrod, 1874
Official Definition- crown (Charadrius hiaticula + Scolopax minor + Larus marinus) (Sangster, 2020; Registration Number 282)
Comments- While Huxley (1867) is sometimes credited with the name, he used Charadriomorphae.
References- Huxley, 1867. On the classification of birds; and on the taxonomic value of the modifications of certain of the cranial bones observable in that class. Proceedings of the Zoological Society of London. 1867, 415-472.
Garrod, 1874. On certain muscles of birds and their value in the classification. Part II. Proceedings of the Zoological Society of London. 1874, 111-123.
Sangster, 2020. Charadriiformes A. H. Garrod 1874 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1268-1271.

Phaethoquornithes Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- crown (Phaethon aethereus, Pelecanus onocrotalus <- Apus apus, Charadrius hiatcula, Musophaga violacea,Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 704)
Reference- Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Phaethontimorphae Cracraft, 2013
Official Definition- crown (Phaethon aethereus + Eurypyga helias) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 705)
References- Cracraft, 2013. Avian higher-level relationships and classification: Nonpasseriforms. In Dickinson and Remsen (eds.). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition, vol. 1: Non-passerines. Aves Press. xxi-xliii.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Phaethontiformes

Eurypygiformes

Aequornithes Mayr, 2011
Official Definition- crown (Gavia immer + Pelecanus onocrotalus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 706)
= Natatores Illiger, 1811
= Aequornithia Cracraft, 2013
References- Illiger, 1811. Prodromus Systematis Mammalium et Avium. C. Salfeld. 301 pp.
Mayr, 2011 (online 2010). Metaves, Mirandornithes, Strisores and other novelties - a critical review of the higher-level phylogeny of neornithine birds. Journal of Zoological Systematics and Evolutionary Research. 49(1), 58-76.
Cracraft, 2013. Avian higher-level relationships and classification: Nonpasseriforms. In Dickinson and Remsen (eds.). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition, vol. 1: Non-passerines. Aves Press. xxi-xliii.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Gaviiformes Wetmore and Miller, 1926

Feraequornithes Sangster and Mayr, 2021
Official Definition- crown (Pelecanus onocrotalus + Procellaria aequinoctialis) (Sangster and Mayr, 2021; Registration Number 416)
Reference- Sangster and Mayr, 2021. Feraequornithes: A name for the clade formed by Procellariiformes, Sphenisciformes, Ciconiiformes, Suliformes and Pelecaniformes (Aves). Vertebrate Zoology. 71, 49-53.

Procellariimorphae Livezey and Zusi, 2007
Official Definition- crown (Procellaria aequinoctialis + Spheniscus demersus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 707)
= Austrodyptornithes Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleson, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
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.
Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Sphenisciformes

Procellariiformes Fürbringer, 1888
Official Definition- crown (Procellaria aequinoctialis + Diomedea exulans + Pelecanoides urinatrix + Hydrobates pelagicus + Oceanites oceanicus) (Sangster, 2020; Registration Number 283)
References- Fürbringer, 1888. Untersuchungen zur Morphologie und Systematik der Vögel zugleich ein Beitrag zur Anatomie der Stütz- und Bewegungsorgane (Vol. 2). T. J. Van Holkema. 834 pp.
Sangster, 2020. Procellariiformes M. Fürbringer 1888 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1272-1275.

Lonchodytidae Brodkorb, 1963
Lonchodytes Brodkorb, 1963
L. estesi Brodkorb, 1963
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Holotype- (UCMP 53954) distal tarsometatarsus
Comments- Brodkorb (1963) originally described this as belonging to a new family of loons, but only stated differences from gaviids, not gaviiform synapomorphies. Olson and Feduccia (1980) stated it was more similar to Charadrii than gaviids based on three symplesiomorphies and also noted Brodkorb no longer believed it was gaviiform. Cracraft (1982) excluded Lonchodytes from his Gaviomorphae, which is today recognized as a polyphyletic assemblage of diving forms (hesperornithines, loons, grebes). Hope (2002) believed this was most similar to procellariids and referred it to Procellariiformes based on seven characters, though she noted all were also present in loons, 2 and 5-7 were also present in grebes, and 1-4 were present in alcid charadriiforms. Mayr et al. (2018) suggested Lonchodytes "likewise needs to be compared with the distal tarsometatarsus preserved in the holotype of Vegavis iaai", and indeed probable vegaviid MLP 98-1-10-76 shows at least characters 1, 2 and 5. Neogaeornis has characters 1, 2, 4 and 5 but lacks 3 and arguably 7, and is overall more similar to loons (reduced trochlea II) and grebes (subequal trochlea III and IV which lack ginglymoidy) than to Lonchodytes. Thus if Neogaeornis is a vegaviid, Lonchodytes is unlikely to be unless it is a far more plesiomorphic form.
References- Brodkorb, 1963. Birds from the Upper Cretaceous of Wyoming. in Sibley (ed.). Proceedings of the XIII International Ornithological Congress. 50-70.
Olson and Feduccia, 1980. Relationships and evolution of flamingos (Aves: Phoenicopteridae). Smithsonian Contributions to Zoology. 316, 73 pp.
Cracraft, 1982. Phylogenetic relationships and monophyly of loons, grebes, and hesperornithiform birds, with comments on the early history of birds. Systematic Zoology. 31(1), 35-56.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Mayr, De Pietri, Scofield and Worthy, 2018. On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 - Neornithine birds from the Upper Cretaceous of the Southern Hemisphere. Cretaceous Research. 86, 178-185.

Tytthostonychidae Olson and Parris, 1987
Tytthostonyx Olson and Parris, 1987
T. glauconiticus Olson and Parris, 1987
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Holotype- (NJSM 11341) incomplete humerus (~110 mm)
Diagnosis- (after Olson and Parris, 1987) ectepicondylar spur intermediate in development between Pelecaniformes and other Procellariiformes; deltopectoral crest extends much farther distally than other Procellariiformes or Limnofregata; ventral condyle very rounded, extending distally well past dorsal condyle.
Comments- The holotype was discovered in 1973 and described by Olson and Parris (1987) as a basal procellariiform also similar to Limnofregata. This was interpreted as supporting a procellariiform-pelecaniform clade and a basal placement for Fregatidae inside Pelecaniformes. Molecular studies indicate sphenisciforms are more closely related to procellariiforms though, with ciconiids sister to pelecaniforms. Bourdon et al. (2008) stated Tytthostonyx was definitely not a procellariiform because "its condylae are shorebird-like and very similar to those of Lithoptila", and possibly closely related to prophaethontids. Yet adding Tytthostonyx to Smith's (2010) pelecaniform matrix found it to clade with procellariiforms to the exclusion of other taxa, including prophaethontids.
References- Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.
Bourdon, Mourer-Chauviré, Amaghzaz and Bouya, 2008. New specimens of Lithoptila abdounensis (Aves, Prophaethontidae) from the Lower Paleogene of Morocco. Journal of Vertebrate Paleontology. 28, 751-761.
Smith, 2010. Phylogenetic analysis of Pelecaniformes (Aves) based on osteological data: Implications for waterbird phylogeny and fossil calibration studies. PLoS ONE. 5(10), e13354.

unnamed possible procellariiform (Olson and Parris, 1987)
Late Maastrichtian-Early Danian, Late Cretaceous-Early Paleocene
Hornerstown Formation, New Jersey, US
Material- (ANSP 15713) distal ulna
References- Olson and Parris, 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology. 63, 22 pp.

Diomedeidae Gray, 1840

undescribed possible diomedeid (Kurochkin, 1995a,b)
Early Maastrichtian, Late Cretaceous
Nemegt Formation, Mongolia
Material- furcular fragment
Comments- Kurochkin (1995a) wrote "the partial furcula of an albatross is in our disposal from the Nemegt Formation of Mongolia" and later (1995b) wrote "another record of a Maastrichtian albatross in from the Nemegt Formation of Mongolia." Hope (2002) stated "my brief observation of the specimen was consistent with this determination but did not include detailed comparisons."
References- Kurochkin, 1995a. 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, 1995b. Synopsis of Mesozoic birds and early evolution of class Aves. Archaeopteryx. 13, 47-66.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Pelecanimorphae Livezey and Zusi, 2007
Official Definition- crown (Pelecanus onocrotalus + Sula leucogaster + Ciconia ciconia) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 708)
= Stegano-grallatores Livezey and Zusi, 2007
Comments- Sangster et al. (2022) correctly noted "The name Pelecanimorphae is sometimes ascribed to Huxley, 1867 (e.g. Livezey and Zusi, 2007) but Huxley (1867) did not actually mention this name in his work. Instead, he included the pelicans (Pelecanidae) with other totipalmate birds in a group called Dysporomorphae."
References- Huxley, 1867. On the classification of birds; and on the taxonomic value of the modifications of certain of the cranial bones observable in that class. Proceedings of the Zoological Society of London. April 11, 413-472.
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.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Ciconiiformes

Pelecanes Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- crown (Pelecanus onocrotalus + Sula leucogaster) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 754)
Reference- Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Suliformes Sharpe, 1891
= Steganopodes Illiger, 1811
= Suloidea Reichenbach, 1849 sensu Mathews, 1919

Sulida Sibley and Ahlquist, 1990

Phalacrocoracoidea Bonaparte, 1853 sensu Mathews, 1919

Phalacrocoracidae Bonaparte, 1853

unnamed phalacrocoracid (Hope, 2002)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (AMNH 25272) femur (~47 mm)
Comments- Hope (2002) refers this specimen to Phalacrocoracidae based on several characters including the supposedly unique long raised scar for the M. gastrocnemius lateralis on the lateral distal femur, and distinct diagonal striations on the anterior face of the proximal end for fascicles of the Mm. femorotibiales. Longrich et al. (2011) proposed "putative cormorant remains most likely belong to the Hesperornithes described here", referencing this specimen. While hesperornithines do have a similar lateral distal scar, they lack the anterior striations and even Pasquiaornis is far more robust. Mayr et al. (2018) suggested this "shows an overall resemblance to the femora of Vegavis and Polarornis", but it doesn't show proposed vegaviid synapomorphies (two separated obturator scars, strong curvature in side view), and vegaviids lack the two phalacrocoraciid characters noted above. Vegavis does have an autapomorphic lateral distal crest, but it is more posteriorly placed to be confluent with the fibular crest. Thus Hope's assignment is retained here.
References- Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
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.
Mayr, De Pietri, Scofield and Worthy, 2018. On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 - Neornithine birds from the Upper Cretaceous of the Southern Hemisphere. Cretaceous Research. 86, 178-185.

undescribed phalacrocoracid (Kurochkin, 1995a,b)
Maastrichtian, Late Cretaceous
Nemegt Formation, Mongolia
Material- (PIN coll.) scapula
Comments- Kurochkin (1995a) wrote "we dispose by the cormorant-like scapula from the Nemegt rocks in South Mongolia" and later (1995b) wrote "I have a coromorant-like scapula from the Nemegt rocks, Maastrictian, of South Mongolia, which will be described in the near future." Hope (2002) supported Kurochkin's assignment of this specimen to Phalacrocoracidae based on- coracoid tubercle absent (also in other suloids); impression for M. deltoideus minor deep and recurved around the tip of the acromion; acromion elongate, broad, flat and recurved at tip.
References- Kurochkin, 1995a. 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, 1995b. Synopsis of Mesozoic birds and early evolution of Class Aves. Archaeopteryx. 13, 47-66.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.

Pelecaniformes Sharpe, 1891

Inopinaves Prum, Berv, Dornburg, Field, Townsend, Lemmon and Lemmon, 2015
Reference- Prum, Berv, Dornburg, Field, Townsend, Lemmon and Lemmon, 2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing. Nature. 526, 569-573.

Opisthocomiformes

Telluraves Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleson, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Accipiter nisus + Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 709)
= Dendrornithes Fürbringer, 1888
= Eutelluraves Prum, Berv, Dornburg, Field, Townsend, Lemmon and Lemmon, 2015
References- Fürbringer, 1888. Untersuchungen zur Morphologie und Systematik der Vögel zugleich ein Beitrag zur Anatomie der Stütz- und Bewegungsorgane (Vol. 2). T. J. Van Holkema. 834 pp.
Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Prum, Berv, Dornburg, Field, Townsend, Lemmon and Lemmon, 2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing. Nature. 526, 569-573.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Afroaves Ericson, 2012
Official Definition- crown (Accipiter nisus, Colius colius, Picus viridus <- Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 710)
References- Ericson, 2012. Evolution of terrestrial birds in three continents: Biogeography and parallel radiations. Journal of Biogeography. 39(5), 813-824.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Accipitriformes

Strigiformes Sharpe, 1899
Official Definition- crown (Tyto alba + Strix aluco) (Sangster, 2020; Registration Number 284)
Comments- Sangster (2020) notes "Under rank-based nomenclature, Wagler (1830) is considered the author of the name Strigiformes, even though he spelled the name Striges, because he was the first person to publish a name based on Strix at the rank of order. The first author to use Strigiformes appears to have been Sharpe (1899)..."
References- Wagler, 1830. Natürliches System der Amphibien mit vorangehender Classifcation der Säugethiere und Vögel. J. G. Cotta Buchhandlung. 354 pp.
Sharpe, 1899. A Hand-list of the Genera and Species of Birds, Volume I. Taylor and Francis. 303 pp.
Sangster, 2020. Strigiformes R. B. Sharpe 1899 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1276-1279.

Coraciimorphae Cracraft, 2013
Official Definition- crown (Colius colius, Picus viridus <- Accipiter nisus, Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 711)
References- Cracraft, 2013. Avian higher-level relationships and classification: Nonpasseriforms. In Dickinson and Remsen (eds.). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition, vol. 1: Non-passerines. Aves Press. xxi-xliii.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Coliiformes

Cavitaves Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Leptosomus discolor + Picus viridis) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 712)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Leptosomiformes

Eucavitaves Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Trogon viridis + Picus viridis) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 713)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Trogoniformes

Picocoraciades Mayr, 2011 emmend. Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
= Picocoraciae Mayr, 2011
Official Definition- crown (Buceros rhinoceros + Coracias garrulus + Picus viridis) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 714)
Comments- Sangster et al. (2022 online) noted "The name was spelled 'Picocoraciae' by Mayr (2011) and subsequent authors. It is here amended to Picocoraciades to make it grammatically correct (Coraciades is the correct plural of Coracias)."
References- Mayr, 2011 (online 2010). Metaves, Mirandornithes, Strisores and other novelties - a critical review of the higher-level phylogeny of neornithine birds. Journal of Zoological Systematics and Evolutionary Research. 49(1), 58-76.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Bucerotiformes

Picodynastornithes Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Coracias garrulus + Alcedo atthis + Picus viridis) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 715)
References- Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Coraciiformes

Piciformes

Picidae Leach, 1820
Official Definition- crown (Jynx torquilla + Picus viridis) (Sangster, 2020; Registration Number 285)
References- Leach, 1820. Eleventh room. In Leach (ed.). Synopsis of the Contents of the British Museum, Seventeenth Edition. Rich and Arthur Taylor. 65-70.
Sangster, 2020. Picidae W. E. Leach 1820 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1280-1283.

Australaves Ericson, 2012 emmend. Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013
Official Definition- crown (Cariama cristata + Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 716)
= Australavis Ericson, 2012
= Psittacopasserria Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014
Comments- Sangster et al. (2022) note "The name was originally spelled 'Australavis' by Ericson (2012); it was emended to Australaves by Yuri et al. (2013)."
References- Ericson, 2012. Evolution of terrestrial birds in three continents: Biogeography and parallel radiations. Journal of Biogeography. 39(5), 813-824.
Yuri, Kimball, Harshman, Bowie, Braun, Chojnowski, Han, Hackett, Huddleston, Moore, Reddy, Sheldon, Steadman, Witt and Braun, 2013. Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. Biology. 2(1), 419-444.
Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014. Whole-genome analyses resolve early branches in the tree of life of modern birds. Science. 346(6215), 1320-1331.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Cariamiformes

Eufalconimorphae Suh, Paus, Kiefmann, Churakov, Franke, Brosius, Kriegs and Schmitz, 2011
Official Definition- crown (Falco subbuteo + Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022; Registration Number 717)
References- Suh, Paus, Kiefmann, Churakov, Franke, Brosius, Kriegs and Schmitz, 2011. Mesozoic retroposons reveal parrots as the closest living relatives of passerine birds. Nature Communications. 2, 443.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Falconiformes

Psittacopasseres Suh, Paus, Kiefmann, Churakov, Franke, Brosius, Kriegs and Schmitz, 2011 emmend. Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022
Official Definition- crown (Psittacus erithacus + Passer domesticus) (Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022 online; Registration Number 718)
= Psittacopasserae Suh, Paus, Kiefmann, Churakov, Franke, Brosius, Kriegs and Schmitz, 2011
= Passerimorphae Sibley, Ahlquist and Monroe, 1988 sensu Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014
Comments- Sangster et al. (2022) state "The name was spelled 'Psittacopasserae' by Suh et al. (2011) and subsequent authors. It is here amended to Psittacopasseres to make it grammatically correct (Passeres is the correct plural of Passer)."
References- Sibley, Ahlquist and Monroe, 1988. A classification of the living birds of the world based on DNA-DNA hybridization studies. The Auk. 105(3), 409-423.
Suh, Paus, Kiefmann, Churakov, Franke, Brosius, Kriegs and Schmitz, 2011. Mesozoic retroposons reveal parrots as the closest living relatives of passerine birds. Nature Communications. 2, 443.
Jarvis, Mirarab, Aberer, Li, Houde, Li, Ho, Faircloth, Nabholz, Howard, Suh, Weber, Fonseca, Li, Zhang, Li, Zhou, Narula, Liu, Ganapathy, Boussau, Bayzid, Zavidovych, Subramanian, Gabaldon, Capella-Gutierrez, Huerta-Cepas, Rekepalli, Munch, Schierup, Lindow, Warren, Ray, Green, Bruford, Zhan, Dixon, Li, Li, Huang, Derryberry, Bertelsen, Sheldon, Brumfield, Mello, Lovell, Wirthlin, Schneider, Prosdocimi, Samaniego, Velazquez, Alfaro-Nunez, Campos, Petersen, Sicheritz-Ponten, Pas, Bailey, Scofield, Bunce, Lambert, Zhou, Perelman, Driskell, Shapiro, Xiong, Zeng, Liu, Li, Liu, Wu, Xiao, Yinqi, Zheng, Zhang, Yang, Wang, Smeds, Rheindt, Braun, Fjeldsa, Orlando, Barker, Jonsson, Johnson, Koepfli, O'Brien, Haussler, Ryder, Rahbek, Willerslev, Graves, Glenn, McCormack, Burt, Ellegren, Alstrom, Edwards, Stamatakis, Mindell, Cracraft, Braun, Warnow, Jun, Gilbert and Zhang, 2014. Whole-genome analyses resolve early branches in the tree of life of modern birds. Science. 346(6215), 1320-1331.
Sangster, Braun, Johansson, Kimball, Mayr and Suh, 2022. Phylogenetic definitions for 25 higher-level clade names of birds. Avian Research. 13, 100027.

Psittaciformes Fürbringer, 1888
Official Definition- crown (Strigops habroptilus + Psittacus erithacus) (Sangster, 2020; Registration Number 286)
Comments- While sometimes attributed to Wagler (1830), that reference used Psittaci.
References- Wagler, 1830. Natürliches System der Amphibien mit vorangehender Classifcation der Säugethiere und Vögel. J. G. Cotta Buchhandlung. 354 pp.
Fürbringer, 1888. Untersuchungen zur Morphologie und Systematik der Vögel zugleich ein Beitrag zur Anatomie der Stütz- und Bewegungsorgane (Vol. 2). T. J. Van Holkema. 834 pp.
Sangster, 2020. Psittaciformes M. Fürbringer 1888 [G. Sangster], converted clade name. In de Queiroz, Cantino and Gauthier (eds.). Phylonyms: A Companion to the PhyloCode. Taylor & Francis Group. 1284-1287.

unnamed possible psittaciform (Stidham, 1998)
Late Maastrichtian, Late Cretaceous
Lance Formation, Wyoming, US
Material- (UCMP 143274) anterior dentary
Comments- This specimen has been highly controversial. Initially described as a parrot most similar to loriines by Stidham (1998), Dyke and Mayr (1999) dispute the strength of this identification, though Hope (2002) believes it probably came from a parrot. The basic facts are that morphologically, the specimen indeed most similar to loriine psittacids, but that a series of stem-psittaciforms with more plesiomorphic dentaries are known from the Tertiary, making the Lance specimen unexpectedly early and indicative of numerous ghost lineages. Thus is it possible the dentary represents another taxon convergent on loriine psittacids, though contra Mayr (2009) this is likely to be an avian lineage as opposed to an oviraptorosaur.
References- Stidham, 1998. A lower jaw from a Cretaceous parrot. Nature. 396, 29-30.
Dyke and Mayr, 1999. Did parrots exist in the Cretaceous period? Nature. 399, 317-318.
Stidham, 1999. Did parrots exist in the Cretaceous period? Nature. 399, 318.
Hope, 2002. The Mesozoic radiation of Neornithes. In Chiappe and Witmer (eds.). Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press. 339-388.
Mayr, 2009. Paleogene Fossil Birds. Springer Berlin Heidelberg. 262 pp.

Passeriformes