Pronounced (HES-per-OR-nis re-GAL-is)
Name Means: “Western Bird”
Discovery Location: Trego County, Kansas
Diet: Fish (Piscivorous)
Period: Late Cretaceous
Age: 83 million years
Formation: Niobrara Chalk
Length: 4-6 ft.
Hesperornis were large flightless birds that swam in the oceans of the late Cretaceous and preyed on small fish. It is likely that they swam and fed much like modern loons. The jaws were lined with sharp teeth, much different than birds of today. In fact, Hesperornis jaws were originally described as belonging to a small mosasaur.
Professor O. C. Marsh found the first remains of Hesperornis regalis in the Niobrara Chalk of Trego County, Kansas on July 25, 1871.