Before and after 1885, many other fossils have been discovered in Kansas and throughout the world. By studying fossils and rocks, scientists are able to determine what plants and animals lived during different periods and what their environments were like. This fossil was formed from a starfish that lived about 300 million years ago in the Pennsylvanian Period.
Fossils form only under certain conditions.
Very few plants and animals are fossilized. Dead plants and animals must be buried quickly and not exposed to harsh weather and running water. Deltas, marshes, swamps, and shallow seas are ideal places for fossils to form. Because Kansas has been covered with marshes and seas several times in the past, it has a good supply of fossils. The most common Kansas fossils are marine animals found in rocks formed in the Pennsylvanian, Permian, and Cretaceous periods.