Hesperornis is an extinct genus of flightless aquatic birds that lived during the Santonian to Campanian sub-epochs of the Late Cretaceous 89-65 mya 1 of the lesser known discoveries of paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an important early find in the history of avian paleontology.Famous locations for Hesperornis are the Late Cretaceous marine limestones from Kansas and the marine shales from Canada but the genus had probably a Holarctic distribution.
Hesperornis was a large bird reaching up to 2 meters 6.5 feet in length It had virtually no wings and swam with its powerful hind legs. The toes were probably lobed rather than webbed as in today's grebes like in these the toes could rotate well, which is necessary to decrease drag in lobed feet but not in webbed ones like in loons where the toes are simply folded together.
Like many other Mesozoic birds such as Ichthyornis, Hesperornis had teeth in its beak which were used to hold prey most likely fish In the hesperornithiform lineage they were of a different arrangement than in any other known bird or in non avian theropod dinosaurs with the teeth sitting in a longitudinal groove rather than in individual sockets in a notable case of convergent evolution with mosasaurs.
Thanks to the use of genesis 7 the Hesperornis was brought back to life and roamed the gulfs of mexico and california.and areas arounded the californian coastline.