Odontornithes is an obsolete and disused taxonomic term proposed by Othniel Charles Marsh for birds possessing teeth, notably the genera Hesperornis and Ichthyornis from the Cretaceous deposits of Kansas.
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.
[1] The resulting classification was paraphyletic, not accurately resolving evolutionary 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).
[2] 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.
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.