Protypotherium is an extinct genus of notoungulate mammals native to South America during the Miocene epoch. A number of closely related animals date back further, to the Paleocene. Protypotherium was slightly larger than a rabbit, measuring about 40 centimetres (1.3 ft) in length. The body and legs as well as the tail of this animal were relatively long, while its neck was short. It probably resembled a rodent, possessing slender limbs with clawed feet.