Hemicyon

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Hemicyon
Fossil range: Early to Late Miocene

Hemicyon sansaniensis

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Hemicyonidae
Genus:	Hemicyon

Species

H. barbouri, Lartet 1851
H. californicus
H. cf. stehlini
H. gargan
H. goeriachensis
H. hareni
H. sansaniensis
H. mayorali
H. stehlini
h. teilhardi
H. ursinus
H. youngi

Hemicyon the so-called "dog-bear," literally "Half Dog" (Greek:`Hmikuwn/"hemi-kuôn"), is an extinct genus of bear-like animals that gave rise to the Hemicyonidae lineage. They were about 1.50 m (5 ft) long, 28 inches tall, with somewhat tiger-like proportions and dog-like teeth. They lived during the Miocene (ca. 22 million years ago) in Europe, Asia and North America. Hemicyon are widely accepted to have been hypercarnivorous and highly predaceous. Unlike modern bears, Hemicyon walked on its toes, ie., it was not plantigrade but digitigrade with long metapodials. This suggests that Hemicyonidae must have been an active hunter and a good runner, and presumably hunted on the plains, possibly in packs. This also distinguishes it from the plantigrade short metapodials that bears have and gives it a greater affinity to the digitigrade long metapodials like dogs.

Species of Hemicyon are recognized in the medial Hemingfordian (ca. 18 million years ago) Thomas Farm local fauna. This record of Hemicyon represents the earliest occurrence of this genus in North America. The Thomas Farm Cynelos Hemicyon is very closely related to European representatives from the early Burdigalian (ca. 20 million years ago).^[1] Other Hemicyon fossil finds include: H. teilhardi from the Middle Miocene Hujialian Formation in the Linxia Basing, Gansu Province, 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 Sante 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. Despite its close proximity to South America, given the geolgical 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. ^[2]