Subhyracodon (Latin: "below the genus Hyracodon"[5]) is an extinct genus of hornless rhinocerotids. With a length of 2.4 m (7 ft 10 in) and an estimated weight of 381 kg (840 lb) in S. mitis,[citation needed] it was a tapir-sized herbivore on the plains of early Oligocene South Dakota 33 million years ago. 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.[citation needed] 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]
| Subhyracodon | |
|---|---|
 | |
| 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] | |
| |
| Synonyms | |
