ichthyornis, n. [NL., fr. Gr. 'ichqy`s, -y`os, a fish + bird.].
An extinct genus of toothed birds found in the American Cretaceous formation. It is remarkable for having biconcave vertebræ, and sharp, conical teeth set in sockets. Its wings were well developed. It is the type of the order Odontotormæ. [1913 Webster]