Odontognathae

(paleontology) An extinct superorder of the avian subclass Neornithes, including all large, flightless aquatic forms and other members of the single order Hesperornithiformes.

One of the two superorders making up the subclass Neornithes, or true birds. It was originally erected to include fossil birds that could fly or that were secondarily flightless but still possessed teeth; it was regarded therefore as an evolutionary step between Archaeopteryx and fully evolved modern birds. It is now considered to contain only a simple order, Hesperornithiformes, of which the best-known family is the Hesperornithidae containing several species from the Upper Cretaceous of North America. See also Archaeornithes; Aves; Hesperornithiformes; Neornithes.