Hemicyon

Taxobox
name = "Hemicyon"


image_caption = "Hemicyon sansaniensis"
fossil_range = Early to Late Miocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Carnivora
infraorder = Arctoidea
familia = †Hemicyonidae
genus = †"Hemicyon"
genus_authority = Lartet, 1851
subdivision_ranks = Species
subdivision =
* †"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).cite journal | author = Tedford, Richard H. and David Frailey | year = 1976 | title = Review of some Carnivora (Mammalia) from the Thomas Farm local fauna (Hemingfordian, Gilchrist County, Florida) | journal = American Museum novitates | issue = 2610 | pages = 720–734 | url = http://digitallibrary.amnh.org/dspace/handle/2246/2925] 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. cite journal | author = MacFadden, Bruce J. | year = 2006 | title = North American Miocene Land Mammals from Panama | journal = Journal of Vertebrate Paleontology | volume = 26 | issue = 3 | pages = 720–734 | url = http://www.vertpaleo.org/publications/jvp/26-720-734.cfm | doi = 10.1671/0272-4634(2006)26 [720:NAMLMF] 2.0.CO;2 | doilabel = 10.1671/0272-4634(2006)26[720:NAMLMF]2.0.CO;2]

References