Archaeotherium is an extinct artiodactyl genus

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 the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Entelodontidae, endemic to North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 during the 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...

 epoch (38—24.8 mya), existing for approximately . Archaeotherium was about 1.2m tall at the shoulder and around 2m long and weighing around 270kg.

It was a relative of javelina

Peccary

A peccary is a medium-sized mammal of the family Tayassuidae, or New World Pigs. Peccaries are members of the artiodactyl suborder Suina, as are the pig family and possibly the hippopotamus family...

s and pig

Pig

A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...

s. Evidence from the Wyoming Dinosaur Center

Wyoming Dinosaur Center

right|290px|thumb|Wyoming Dinosaur CenterThe Wyoming Dinosaur Center is located in Thermopolis, Wyoming and is one of the few dinosaur museums in the world to have its own excavation within driving distance...

 suggests that Archaeotherium, like modern carnivores, kept caches of food when their hunting was unsuccessful. These bones were mainly those of Teleoceras

Teleoceras

Teleoceras is an extinct genus of grazing rhinoceros that lived in North America during the Miocene epoch, which ended about 5.3 million years ago, all the way to the early Pliocene epoch....

.

Taxonomy

Archaeotherium was named by Leidy (1850). Its type is Archaeotherium mortoni. It was synonymized subjectively with Entelodon by Joseph Leidy

Joseph Leidy

Joseph Leidy was an American paleontologist.Leidy was professor of anatomy at the University of Pennsylvania, and later was a professor of natural history at Swarthmore College. His book Extinct Fauna of Dakota and Nebraska contained many species not previously described and many previously...

 (1853) and synonymized subjectively with Elotherium by Leidy (1857). It was assigned to Entelodontidae by Leidy (1850), Peterson (1909), Scott (1940), Galbreath (1953), Russell (1980), Carroll (1988) and Effinger (1998).

Morphology

In life, Archaeotherium probably resembled a large, fanged, peccary with bumps projecting from the side of its head. It had high shoulders, presumably to carry strong neck muscles to support the heavy head. The brain was tiny, but had relatively large olfactory lobes, suggesting that the animal had a keen sense of smell.

The largest (and type) species, A. mortoni was an aggressive, cow-sized apex predator. Rhino

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....

 jaws and other mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 bones have been found with bite marks on them that match the large canines of A. mortoni. A fossil trackway

Fossil trackway

A fossil trackway is a type of trace fossil, a trackway made by an organism. Many fossil trackways were made by dinosaurs, early tetrapods, and other quadrupeds and bipeds on land...

 in Toadstool Park

Toadstool Geologic Park

Toadstool Geologic Park is located in the Oglala National Grassland in far northwestern Nebraska. It is operated by the United States Forest Service. It contains a badlands landscape and a reconstructed sod house...

 depicts the path of a Subhyracodon

Subhyracodon

Subhyracodon is an extinct genus of cow-sized rhinoceroses. It was a medium sized herbivore on the plains of early Oligocene South Dakota 33 million years ago , smaller than only the Brontops and the chalicotheres. Subhyracodon had no horns, relying more on its speed to escape, but a species found...

walking forward, stopping to see an Archaeotherium approach, then breaking into a gallop with the entelodont chasing after it. In leaner times, it is suggested that Archaeotherium dug for roots and tubers, as with other pig-like mammals.

Body mass

A single specimen was examined by M. Mendoza, C. M. Janis, and P. Palmqvist for body mass and was estimated to have a weight of 1091.8 kg (2,407 lb). The second was estimated to have a weight of 129.1 kg (284.6 lb).