- a toothed aquatic bird of the extinct genus Hesperornis, fossils of which are found in rocks of Cretaceous age in Kansas, having the rear legs modified for swimming and reaching a length of more than 4 feet (1.2 meters).
Origin of hesperornis
< New Latin (1872) < Greek Hésper(os) Hesperus + órnis bird
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for hesperornis
This order includes only an extinct N. American bird Hesperornis.The Vertebrate Skeleton
Sidney H. Reynolds
They've named him the "Hesperornis," which means "western bird."The Adventures of a Grain of Dust
The less numerous Hesperornis group were large and powerful divers.
They crept on all fours, they climbed with fingers and toes, they dived headlong, and swam as skilfully as any Hesperornis of old.Jungle Peace
They are of two leading types, of which the Ichthyornis and Hesperornis are the standard specimens.