Hesperocyon gregarius Age: Oligocene, Rupelian stage (33.9 - 28.1 million years ago) Location: Chadron formation, Chadron group, Crawford, Nebraska, USA
Hesperocyon were the first true canids. They first appear in the fossil record during the mid eocene, about 38 million years ago. The animal was somewhat fox like. They evolved in forest conditions and were probably very good at climbing trees.