Fossils

Swimming Reptiles: Mosasaurs / Plesiosaurs / Turtles

Flying Reptiles: Pteranodons

Bony Fish: Xiphactinus / Gillicus / Saurodon / Pentanogmius / Pachyrhizodus / Cimolichthys / Apsopelix / Enchodus / Ichthyodectes / Protosphyraena

Sharks: Cretoxyrhina / Squalicorax / Ptychodus / Rhinobatos

Invertebrates

Crinoids: Uintacrinus

Clams & Oysters: Inoceramus / Rudistes / Ostrea congesta

Cephalopods: Spinaptychus & Rugaptychus / Niobrarateuthis bonneri

Birds: Hesperornis / Ichthyornis

Other Niobrara fossils: Coprolites / Fossil Tree

Other Resources: Geology of Western Kansas / Bonner Fossil Hunters / Oceans of Kansas (off-site)

Probably the rarest vertebrate fossils found in the Smoky Hill chalk are birds. They were first found in the 1870’s by Professor Mudge of Kansas State as well as the Yale Paleontogical expedition. The discoveries of two types of birds with conical teeth, set in grooves in the jaws, caused quite a stir in the scientific community. This discovery, showing the evolution of bird anatomy, gave strong credibility to Darwin’s theory. 

In 1880, Professor O.C. Marsh of Yale published the definitive book on toothed birds. Two main genera were described at that time: Hesperornis and Ichthyornis.

Hesperornis

Hesperornis (hess-per-orr-niss) was a large, loon-like bird that had huge feet adapted for swimming and small teeth designed for catching fish. It could not fly, having only small vestigal bones for wings. Hesperornis reached a length of five feet and probably only left the water to lay eggs.

Ichthyornis

Ichthyornis (ick-thee-orr-niss) was a true bird in every sense, except for teeth in its jaws. Resembling a tern or gull in size, it was undoubtedly an excellent flyer. It may have been able to dive deep for fish like present-day auks. Ichthyornis probably laid eggs on land.

You can read about Ichthyornis evolution in this recent paper (PDF). Barbara, Chuck, and their collections helped in this research!