What is "uintan"

The Uintan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 46,200,000 to 42,000,000 years BP lasting .

It is usually considered to fall within the Eocene epoch. The Uintan is preceded by the Bridgerian and followed by the Duchesnean NALMA stages.