Temnocyon are an extinct 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 carnivorous mammals belonging to the family of Amphicyonidae (Bear-dog) 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...

  that lived 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...

 to Early Miocene

Early Miocene

The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....

 approximately 30.3—20.6 mya existing approximately .

Taxonomy

Temnocyon was named by Cope (1879). Its type is Temnocyon altigenis. It was assigned to Amphicyonidae by Cope (1879) and Carroll (1988); and to Temnocyoninae by Hunt (1998).

Morphology

A single specimen was examined for by body mass by Legendre and Roth. It was estimated to have weighed 21.3 kg (47 lb).

Fossil distribution

The first fossils are recorded in North America at Logan Butte in the John Day

John Day Fossil Beds National Monument

John Day Fossil Beds National Monument is a U.S. National Monument in Wheeler and Grant counties in east-central Oregon. Located within the John Day River basin and managed by the National Park Service, the park is known for its well-preserved layers of fossil plants and mammals that lived in the...

 beds of Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 29–29.5 Ma., in the Sharps Formation of the Wounded Knee area

Wounded Knee, South Dakota

Wounded Knee is a census-designated place in Shannon County, South Dakota, United States. The population was 382 at the 2010 census....

, 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...

 28–29.5 Ma, and in the Gering Formation at Wildcat Ridge

Wildcat Hills

The Wildcat Hills are an escarpment between the North Platte River and Pumpkin Creek in the western Nebraska Panhandle. Located in Banner, Morrill, and Scotts Bluff counties, the high tableland between the streams has been eroded by wind and water into a region of forested buttes, ridges and...

, Nebraska

Nebraska

Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....

 28.3 Ma. These early temnocyonines attained the size of coyotes or small wolves (15–30 kg) are identified by a uniquely specialized dentition. The last documented occurrences of temnocyonines are found in sediments in northwest Nebraska and southeastern Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

(Hunt, 2004).