Hesperornis 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.
Image: Hesperornis at AMNH
Image: Hesperornis BW (white background)
Marsh's now-obsolete 1880 reconstruction of H. regalis
H. regalis specimen at the AMNH
Othniel Charles Marsh was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among his legacies are the discovery or description of dozens of new species and theories on the origins of birds.
Othniel Charles Marsh
Othniel Marsh (center, back row) and assistants ready for digging in 1872
Hesperornis regalis, a species of ancient flightless bird with teeth, as drawn by Othniel Marsh, and published in his book, Odontornithes: A Monograph on the Extinct Toothed Birds of North America.