Hesperornis

Hesperornis (from Ancient Greek ἕσπερος (hésperos), meaning "western", and ὄρνις (órnis), meaning "bird") is a genus of cormorant-like ornithuran that spanned throughout the Campanian age, and possibly even up to the early Maastrichtian age, of the Late Cretaceous period. One of the lesser-known discoveries of the paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an early find in the history of avian paleontology. Locations for Hesperornis fossils include the Late Cretaceous marine limestones from Kansas and the marine shales from Canada. Nine species are recognised, eight of which have been recovered from rocks in North America and one from Russia.

==Description== thumb|left|Life restoration Hesperornis was a large bird, measuring about long and weighing around . It had virtually no wings, and swam with its powerful hind legs. Studies on the feet initially indicated that Hesperornis and kin had lobed toes similar to modern-day grebes, as opposed to webbed toes as seen in most aquatic birds such as loons. More recent work looking at the morphometrics of the feet in hesperornithiformes and modern sea birds has thrown this interpretation into question, making webbed toes equally as likely as lobed toes for this group.