The White River Group

The White River group covers the Late Eocene to the Late Oligocene epochs of the Cenozoic era, often referred to as the age of mammals. In the Eocene the fossil record shows a tropical forest environment with the earliest known species of alligator and large large browsing mammals like Megacerops. Up in the Oligocene however, fossils indicate the environment changed into a more open forest and grassland habitat with notable residents including the early horse species Mesohippus and the ferocious entelodont Archeaotherium. With such well preserved fossils constantly eroding out from these badlands paleontologists are always on the hunt to ensure these fossils are found. The White River is of interest to High Plains Paleontology for its potential to yield fossil material that provides valuable insight into Early Cenozoic ecosystems.