2.5" Fossil Brontotherium (Titanothere) Vertebrae - South Dakota

This is a fossil vertebrae of Brontotherium, a type of Titanothere with small proximal portions of the vertebral processes still attached. It was collected from the Eocene aged Chadron Formation of South Dakota.

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.