Subhyracodon
Encyclopedia
Subhyracodon is an extinct genus
of cow-sized rhinoceros
es. It was a medium sized herbivore on the plains of early Oligocene
South Dakota
33 million years ago (White River Fauna
), smaller than only the Brontops
and the chalicothere
s. Subhyracodon had no horns, relying more on its speed to escape, but a species found at Wind Cave National Park
had a pair of bony nasal ridges. The genera Caenopus and Aceratherium were both synonomized with Subhyracodon
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of cow-sized rhinoceros
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....
es. It was a medium sized herbivore on the plains of early Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
South Dakota
South Dakota
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...
33 million years ago (White River Fauna
White River Fauna
The White River Fauna are fossil animals found in the White River Badlands of South Dakota, Wyoming and Nebraska in the United States including the Badlands National Park. The fossils have been found in the Chadron, Brule, and the Arikaree Formations...
), smaller than only the Brontops
Brontops
Brontops is an extinct genus of rhinoceros-like perissodactyl mammal.According to one source, Brontops is subsumed into genus Megacerops.-Appearance:...
and the chalicothere
Chalicothere
Chalicotheres were a group of herbivorous, odd-toed ungulate mammals spread throughout North America, Europe, Asia, and Africa during the Early Eocene to Early Pleistocene subepochs living from 55.8 mya—781,000 years ago, existing for approximately .They evolved around 40 million years ago from...
s. Subhyracodon had no horns, relying more on its speed to escape, but a species found at Wind Cave National Park
Wind Cave National Park
Wind Cave National Park is a United States national park north of the town of Hot Springs in western South Dakota. Established in 1903 by President Theodore Roosevelt, it was the seventh U.S. National Park and the first cave to be designated a national park anywhere in the world. The cave is...
had a pair of bony nasal ridges. The genera Caenopus and Aceratherium were both synonomized with Subhyracodon