''Hemicyon'', also known as the "dog-bear" (literally "half dog", from Greek (half) + (dog)), is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of hemicyonine bear, which probably originated in Eurasia but was found in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

and North America during the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

epoch (), existing for approximately . ''Hemicyon'' is the best-known genus in the

Hemicyoninae Hemicyoninae is an extinct subfamily of Ursidae, often called dog bears (literally "half dog" (Greek: )). They were bear-like carnivorans living in Europe, North America, Africa and Asia during the Oligocene through Miocene epochs 33.9–5.3&nb ...

, a subfamily intermediate between bears and their

canid Canidae (; from Latin, '' canis'', " dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found withi ...

ancestors but most often classified as bears. Hemicyonid bears should not be confused with Amphicyonids (bear-dogs), which are their own separate family of

carnivores A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other so ...

Morphology

''Hemicyon'' was about long, and tall, with and carnassial blades on its teeth for cutting meat. ''Hemicyon'' is widely accepted to have been

hypercarnivorous A hypercarnivore is an animal which has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant exampl ...

and highly

predaceous Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. Unlike modern bears, ''Hemicyon'' walked on its toes; it was not plantigrade, but digitigrade, with long

metapodials Metapodials are long bones of the hand (metacarpals) and feet (metatarsal The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes ...

. This suggests that ''Hemicyon'' must have been an active hunter and a good runner, and presumably hunted by pursuing prey on open ground. In life, the genus would have looked something like a combination of a dog and a bear.

Fossil sites

Species of ''Hemicyon'' are recognized in the medial Hemingfordian (ca. 18 million years ago)

Thomas Farm site The Thomas Farm site is an Early Miocene, Hemingfordian assemblage of vertebrate fossils located in Gilchrist County, northern Florida. The Thomas Farm site is one of the richest terrestrial deposits of Miocene vertebrates in the 18 Ma range f ...

local fauna. This record of ''Hemicyon'' represents the earliest occurrence of this genus in North America. The Thomas Farm ''Hemicyon'' is very closely related to European representatives from the early

Burdigalian The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest w ...

(ca. 20 million years ago). Other ''Hemicyon'' fossil finds include: ''H. teilhardi'' from the Middle Miocene Hujialian Formation in the Linxia Basing,

Gansu Province Gansu (, ; alternately romanized as Kansu) is a province in Northwest China. Its capital and largest city is Lanzhou, in the southeast part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibeta ...

, China; an Early Miocene ''Hemicyon'' from Lanzhu Basin Shan Mong fauna, China; ''Hemicyon'' of the Mid-Miocene Dongxiang and Laogou Formation in Linxia Basin on the northeast margin of the Tibetan Plateau; Mid-Miocene ''H. sansaniensis'' of Arroyo del Val area, Villafeliche, Zaragoza Province, Spain; Mid-Miocene ''H. mayorali'' of Tarazona de Aragon, Spain; a ''Hemicyon'' found at the Somosaguas site, Pozuelo de Alarcón, Madrid; ''H. sansaniensis'' from the Mid-Miocene Anchitherium fauna of İnönü locality, NW Ankara; a Lower Miocene ( Eggenburgian-Ottnangian: ca. 20 Ma) ''H stehlini'' found in the coal bed of Banovići Basin, Bosnia; an Early Hemingfordian hemicyonid (ca. 16 Ma) from the Pollack Farm Fauna, Delaware; and an excellent ''Hemicyon'' specimen from the Miocene Santa Fe Formation, New Mexico. Hemicyonidae fossil evidence may also have been found in the Gaillard Cut Local Fauna, former Canal Zone, Republic of Panama, but it is indeterminant with

Amphicyonidae Amphicyonidae is an extinct family of terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an ...

. Despite its close proximity to South America, given the geological context, the Gaillard Cut Local Fauna are distinctly North American fauna and the age of this assemblage is dated between 19.5 and 14 Ma.

References

{{Taxonbar, from=Q1035243 Hemicyonids Miocene carnivorans Miocene mammals of Asia Miocene mammals of Europe Miocene mammals of North America Fossil taxa described in 1851 Prehistoric carnivoran genera