Source : Webster's Revised Unabridged Dictionary (1913)

Ichthyornis \Ich`thy*or"nis\, n. [NL., fr. Gr. ?, ?, 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].