Hesperornis belongs to the family of aquatic birds which existed during the Campanian age of the Late Cretaceous period, over 83.5–78 million years ago. The species was discovered by O. C. Marsh in the late 19th century. It measured 6 feet in length and possessed narrow beak with grooved teeth sockets, lobed toes and strong hind legs.

Hesperornis 1

Hesperornis 2

Hesperornis 3

Hesperornis 4