''Temnocyon'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

bear-dog Amphicyonidae is an extinct family of terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene (around 45 mya), spread to Europe by the late Eocene (35 mya), and appear in Asia, an ...

s endemic to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. It lived from the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

approximately 30.8—20.4 mya, existing for about . The first fossils are recorded in North America at Logan Butte in the John Day beds of

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, in the Sharps Formation of the Wounded Knee area,

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...

, and in the Gering Formation at Wildcat Ridge,

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

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

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

.Hunt, Robert M, Jr. (2004) "Global Climate and the Evolution of Large Mammalian Carnivores during the Later Cenozoic in North America" in Cenozoic Carnivores and Global Climate by Robert M. Hunt, J

References

Bear dogs Oligocene carnivorans Miocene bear dogs Aquitanian genus extinctions Cenozoic mammals of North America White River Fauna Oligocene genus first appearances Prehistoric carnivoran genera {{paleo-carnivora-stub