Odontornithes is an obsolete and disused taxonomic term proposed by Othniel Charles Marsh for

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s possessing teeth, notably the genera '' Hesperornis'' and '' Ichthyornis'' from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

deposits of

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

. In 1875 Marsh divided this "subclass" into Odontolcae, with the teeth standing in grooves, and Odontotormae, with the teeth in separate alveoles or sockets. In his 1880 work, ''Odontornithes: A monograph on the extinct toothed birds of North America'', he added the Sauriurae, represented by '' Archaeopteryx'', as a third order. The resulting classification was

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, not accurately resolving

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

ary relationships, and so it has been abandoned by most modern scientists, though at least one 21st century paper re-used the concept under the older name Odontoholomorphae (first coined by Stejneger, 1885).Livezey, B.C. & Zusi, R.L. (2007): Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion. '' Zoological Journal of the Linnean Society'' no 149(1), pp 1-95 Étienne Geoffroy Saint-Hilaire stated in 1821 that he had found a considerable number of tooth buds in the upper and lower jaws of ''Palaeornis torquatus'', the rose-ringed parakeet. Émile Blanchard felt justified in recognizing flakes of dentine. However, M. Braun and especially P. Fraisse showed later that the structures in question are of the same kind as the well-known serrated "teeth" of the bill of anserine birds. In fact the papillae observed in the embryonic birds are the soft cutaneous extensions into the surrounding horny sheath of the bill, comparable to the well-known nutritive papillae in a horse's hoof. They are easily exposed in the well-macerated under jaw of a parrot, after removal of the horny sheath. Occasionally calcification occurs in or around these papillae, as it does regularly in the egg tooth of the embryos of all birds. The best known of the "Odontornithes" are '' Hesperornis regalis'', standing about 3 ft. high, the somewhat taller '' H. crassipes'', and '' Ichthyornis dispar''. '' Hesperornis'' looked somewhat similar to a

loon Loons (North American English) or divers (British English, British / Irish English) are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus ''Gavia'', family (biolog ...

, while '' Ichthyornis'' was quite similar to a gull or petrel. However, they were entirely distinct groups of birds and merely shared with modern birds some distant ancestry in the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

. The ''Hesperornis'' lineage may have derived even sooner or possibly independently from the ancestors of modern birds.

References

* (1880): ''Odontornithes'', ''a Monograph on the Extinct Toothed Birds of North America''. Government Printing Office, Washington DC. Vertebrate paleozoology Obsolete bird taxa Vertebrate subclasses Birds by classification Paraphyletic groups {{paleo-bird-stub

See also

References