Hesperornis regalis in the context of "Campanian"

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.