Meniscotherium
Meniscotherium is an extinct genus of dog-sized mammal which lived 54–38 million years ago. It was a herbivore and had hooves. Fossils have been found in Utah, New Mexico. and Colorado. Many individuals have been found together, indicating that it lived in groups.[1]
Body mass in M. chamense is estimated to be 5–17 kg, making it about the size of a small dog.[2]
A 2014 cladistic analysis places it within stem perissodactyls.[3]