Oligocene Mammals - Brule Formation - Shark Tooth Listing By Species

During the Early Oligocene, there were abundant land mammals in North America. Today, their fossil remains are found in the Brule Fm. The Brule Fm. is located in the northwestern US and was deposited between 33 and 30 million years ago (Rupelian age). 

The following Brule Fm. mammals are posted: 

Hesperocyon gregarius  -  an early dog-like mammal

Hyracodon nebraskensis  - an early Rhinoceras 

Ischyrmys sp. - a ground squirrel

Leptomeryx evansi  - an early deer-like hornless Ruminant

Merycoidodon culbertson  - an Oreodeont

Merycoidodon gracilis  - an Oreodeont

Mesohippus - an early 3-toed horse

Palaeolagus haydeni  - a rabbbit

Poebrotherium wilsoni - an early cmael