Hesperornis

Hesperornis Temporal range: Late Cretaceous (Campanian), 83.6–72 Ma PreꞒ Ꞓ O S D C P T J K Pg N Possible early Maastrichtian record
Restored skeleton of H. regalis in diving posture at the American Museum of Natural History
Life reconstruction of H. regalis in diving posture
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Avialae
Clade:	†Hesperornithes
Family:	†Hesperornithidae
Genus:	†Hesperornis Marsh, 1872
Type species
†Hesperornis regalis Marsh, 1872
Species
†H. regalis Marsh, 1872 †H. crassipes (Marsh, 1876) †H. gracilis Marsh, 1876 †H. altus (Marsh, 1893) †H. montana Schufeldt, 1915 †H. rossicus Nesov & Yarkov, 1993 †H. bairdi Martin & Lim, 2002 †H. chowi Martin & Lim, 2002 †H. macdonaldi Martin & Lim, 2002 †H. mengeli Martin & Lim, 2002 †H. lumgairi Aotsuka & Sato, 2016
Synonyms
Lestornis Marsh, 1876 Coniornis Marsh, 1893 Hargeria Lucas, 1903

Hesperornis (meaning "western 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.^[1][2] 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.