Subhyracodon

Subhyracodon (Latin: "below" (sub), + Greek: "hyrax" (hyrak = 'shrewmouse'), and "tooth" (odontos, referring to the genus Hyracodon)[5]) is an extinct genus of hornless rhinoceroses. With a length of 2.4 m (7 ft 10 in) and a weight estimated of 381.3 kg (841 lb) (in S. mitis), it was a tapir-sized herbivore on the plains of early Oligocene South Dakota 33 million years ago (White River Fauna). It coexisted with other perissodactyls such as horses, brontotheres, and chalicotheres.[6] Subhyracodon had no horns, relying more on its speed to escape from predators, but a species found at Wind Cave National Park had a pair of bony nasal ridges. The genus Caenopus and species originally referred to as Aceratherium were synonymized into Subhyracodon.[7] It has been suggested to be one of the oldest known members of the subfamily Elasmotheriinae by some studies,[8] though other studies place it firmly outside the Rhinocerotinae-Elasmotheriinae split.[9]

Life restoration by Charles R. Knight

Skull

Subhyracodon Temporal range: Late Eocene to Late Oligocene, [1]
Subhyracodon occidentalis skeleton
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	Rhinocerotidae
Genus:	†Subhyracodon Brandt, 1878
Type species
Subhyracodon occidentalis
Species[2]
†S. kewi †S. mitis †S. occidentalis
Synonyms
†Anchirodon Forbes, 1881[3] †Anchisodon Cope, 1879[4] †Caenopus Cope, 1880[4] †Leptaceratherium Osborn, 1898[4]