The Collaborative International Dictionary of English v.0.48:

Ichthyornis \Ich`thy*or"nis\, n. [NL., fr. Gr. 'ichqy`s, -y`os,
   a fish + ? bird.] (Paleon.)
   An extinct genus of toothed birds found in the American
   Cretaceous formation. It is remarkable for having biconcave
   vertebr[ae], and sharp, conical teeth set in sockets. Its
   wings were well developed. It is the type of the order
   Odontotorm[ae].
   [1913 Webster]