Note: Do not rely on this information. It is very old.
OdontornithesOdontornithes, the name proposed by Professor O. C. Marsh for an extinct order of birds, including the remarkable genera Ichthyornis and Hesperornis (q.v.) from the Cretaceous rocks of Kansas, both of which have true teeth. Ichthyornis had powerful wings, a well-developed keel to its breast-bone, biconcave vertebrae, and its teeth in distinct sockets, whilst Hesperornis has the merest rudiment of a wing, a flat breast-bone, saddle-shaped vertebrae, and its teeth in a common alveolar groove. Professor A. Newton consequently prefers to break up this proposed order, relegating the former genus to the order Carinatae and the latter to the Ratitae. [Birds.]