A small collection of fossil vertebrates from a stream channel deposit referred to the Western Gravels is considered Blancan in age. This is based on the presence of the castorid genus Dipoides.
A fossil record of beavers can be traced in the burrows in the White River Badlands of Nebraska. Initially mistaken for the remains of giant freshwater sponges, these devil's corkscrews were dug by ...ancient beavers estimated to be the size of woodchucks or smaller.
