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)

Coprolites

Interesting trace fossils found in the Niobrara Formation are coprolites or petrified animal waste. Coprolites (caw-pro-lites) come in various sizes, shapes and colors and many have pieces of bone and small vertebrae in them. Very large ones are probably from either Xiphactinus fish or mosasaurs. Coprolites that have a definitive spiral shape are from sharks.

An eight food petrified conifer tree on display in Keystone Gallery.

Fossil Tree

The Kansas chalk rarely preserves petrified wood. Since the strata is of marine deposition, trees would have had to drift out to sea, waterlog, sink, and be buried in the ocean silt to fossilize. Pieces of petrified wood can be found on the surface of the chalk, but these were transported by glaciation and flooding from the Rocky Mountains during the Pleistocene epoch.

 Niobrara driftwood must be found in the actual sediment layers of the chalk to verify its true age. It has a more crystalline, porous structure than the flinty, Pleistocene wash wood.