Fossil Brontotherium (Titanothere) Molar - South Dakota

This is a fossil molar of Brontotherium, a type of Titanothere. It was collected from the Eocene aged Chadron Formation of South Dakota. While the feeding surface is a bit worn it has nice root preservation.

Titanothere's are an extinct, massive, mammal that lived during the Eocene. While the very closely resembled a Rhinocerose, they were more closely related to todays horses. They first appeared 54 million years ago and when extinct at the end of the Eocene, 34 million years ago.