The Odontoanserae is a proposed

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

that includes the family

Pelagornithidae The Pelagornithidae, commonly called pelagornithids, pseudodontorns, bony-toothed birds, false-toothed birds or pseudotooth birds, are a prehistoric family of large seabirds. Their fossil remains have been found all over the world in rocks dating ...

(pseudo-toothed birds) and the clade Anserimorphae (the order Anseriformes and their stem-relatives). The placement of the pseudo-toothed birds in the evolutionary tree of birds has been problematic, with some supporting the placement of them near the orders Procellariformes and

Pelecaniformes The Pelecaniformes are an order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such n ...

based on features in the sternum. In 2005 a cladistic analysis had found support in placing pseudo-toothed birds as the sister group to waterfowl. Evidence for this comes from shared characteristics in the skull such as lack of a crest on the underside of the

palatine A palatine or palatinus (in Latin; plural ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman times.

bone and two

condyle A condyle (;Entry "condyle"
in
mandibular process The mandibular prominence is an embryological structure which gives rise to the lower portion of the face. The mandible and lower lip derive from it. The mesenchymal cells within the mandibular prominence condense to form Meckel's cartilage. It i ...

of the quadrate bone, with the middle condyle beakwards of the side condyle. In addition to that, both groups have similar features in their pelvic and pectoral regions. Furthermore, a 2013 study on the growth pattern and structure of the pseudoteeth in ''

Pelagornis ''Pelagornis'' is a widespread genus of prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertain ...

mauretanicus'' shows more support of Odontoanserae as both groups have "soft rhamphotheca, or delayed hardening of the rhamphotheca." In addition to Pelagornithidae and Anseriformes paleontologists also have support in placing mihirungs (

Dromornithidae Dromornithidae, known as mihirungs and informally as thunder birds or demon ducks, were a clade of large, flightless Australian birds of the Oligocene through Pleistocene Epochs. All are now extinct. They were long classified in Struthioniform ...

) and Gastornithids into this group, as they too also share anatomical features in the skull and pelvic bones with waterfowl. The mihirungs and the gastornithids are more derived than the pseudo-tooth birds and are closer to Anseriformes. One hypothesis is that diatrymas and mihirungs are successive sister groups to anseriforms and another hypothesis places mihirungs as crown anseriforms closely related to the screamers ( Anhimidae). Below is the general consensus of the phylogeny. However, a 2017 paper by Worthy and colleagues found an alternative phylogeny concerning Anserimorphae. By adding additional new characters, as well as incorporating several new taxa into established matrices, the authors have found gastornithids and mihirungs to be sister taxa which could be placed in the order

Gastornithiformes Gastornithiformes were an extinct order of giant flightless fowl with fossils found in North America, Eurasia, and possibly Australia. Members of Gastornithidae were long considered to be a part of the order Gruiformes. However, the traditiona ...

. In addition, they have found support that the family

Vegaviidae Vegaviidae is an extinct family of ornithurines, often regarded as stem- anseriforms, which existed during the Late Cretaceous and possibly the Paleocene. Fossils attributed to the family have been found in Canada, Chile, New Zealand, and Antarc ...

(usually classified as crown anseriforms or their sister taxon) are more related to gastornithiforms than to anseriforms; accordingly, they have created the monotypic order Vegaviiformes. The authors did note the bootstrap support is weakly supported and several alternative phylogenies in their paper found gastornithiforms to be stem galliforms instead. These too were weakly supported as well. Below is a simplified phylogeny showing their one phylogeny supporting gastornithiforms as anserimorphs. In 2019 a new species '' Conflicto antarcticus'' was described from Early

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

deposits in

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. Known completely from associated bones from a single individual, Tambussi et al. (2019) incorporated the new taxon into a phylogenetic analysis using the matrix data from Worthy et al. (2017). Their results not only supported the sister grouping of vegaviids with gastornithids and mihirungs (which included Vegaviidae into Gastornithiformes), but also found two taxa, ''

Anatalavis ''Anatalavis'' is genus of prehistoric birds related to ducks and geese, perhaps in particular the magpie-goose. The species ''Anatalavis rex'' – formerly placed in ''Telmatornis'' – is known from the Hornerstown Formation (Late Cretaceous o ...

rex'' and the tall, wading

presbyornithid Presbyornithidae is an extinct group of birds with a global distribution. They had evolved by the late Cretaceous period and became extinct during the early Miocene. Initially, they were believed to present a mix of characters shown by waterbirds ...

s, traditionally placed as part of the anseriform crown, to be stem-anseriforms. Below is the Tambussi et al. (2019) phylogeny.

References

{{Taxonbar, from=Q25305236 Neognathae Birds Extant Maastrichtian first appearances