Bison occidentalis
Bison occidentalis is an extinct species of bison that lived in North America, from about 11,700 to 5,000 years ago, spanning the end of the Pleistocene to the mid-Holocene.[2]
| Bison occidentalis Temporal range: Terminal Pleistocene-Holocene | |
|---|---|
 | |
| Bison occidentalis skull at the Cleveland Museum of Natural History | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Bovidae |
| Subfamily: | Bovinae |
| Genus: | Bison |
| Species: | †B. occidentalis |
| Binomial name | |
| †Bison occidentalis Lucas, 1898 [1] | |
Characteristics
Likely evolving from Bison antiquus, B. occidentalis was smaller overall from its most direct ancestor, but was similar to the distant ancestor the steppe bison (Bison priscus) in size. B. occidentalis had a highly variable morphology, and their horns, which pointed rearward, were much thinner and pointed than other Pleistocene species of bison.[2]
Bison occidentalis, like other bison species, may have existed in small, scattered populations and been unable to increase in numbers until after the Pleistocene epoch ended 10,000 years ago because of competition with other large grazers during the Pleistocene.[3]
Evolution
Bison occidentalis's decrease in size from Bison antiquus was likely caused by both human hunting and natural selection.[4] The smaller size likely helped B. occidentalis increase in population after migrating into North America. As Bison antiquus was forced to lived on open grasslands and faced pressure from human hunting, it responded by downsizing into B. occidentalis. Hybridization of these two bison species produced the modern American bison Bison bison, which further decreased body size and increased population.[4] The wood bison (Bison bison athabascae) preserves some original traits of B. occidentalis which was more similar to the ancestral steppe bison, making the wood bison more primitive than the plains bison (Bison bison bison).[5]
More recently ancient DNA studies have proven interbreeding between B. occidentalis and Bison bison, so B. occidentalis was proposed to have been a localized offshoot of B. antiquus and part of the transition from that chronospecies to modern bison.
Some authors include remains found in continental Eurasia[6][5][7] and the Japanese archipelago.[8]
References
- Stephen Austin Hall (1972). "Holocene Bison occidentalis from Iowa". Journal of Mammalogy. 53 (3): 604–606. doi:10.2307/1379052. JSTOR 1379052.
- McDonald, J. N. (1981). North American bison: their classification and evolution. Berkeley: University of California Press. ISBN 0520040023.
- Lott, Dale F. (2002). American Bison: A Natural History. Berkeley: University of California Press. ISBN 0-520-23338-7.
- Valerius Geist, 1996, Buffalo Nation, Voyageur Press
- C. G Van Zyll de Jong , 1986, A systematic study of recent bison, with particular consideration of the wood bison (Bison bison athabascae Rhoads 1898), p.53, National Museum of Natural Sciences
- Gennady G. Boeskorov, Olga R. Potapova, Albert V. Protopopov, Valery V. Plotnikov, Larry D. Agenbroad, Konstantin S. Kirikov, Innokenty S. Pavlov, Marina V. Shchelchkova, Innocenty N. Belolyubskii, Mikhail D. Tomshin, Rafal Kowalczyk, Sergey P. Davydov, Stanislav D. Kolesov, Alexey N. Tikhonov, Johannes van der Plicht, 2016, The Yukagir Bison: The exterior morphology of a complete frozen mummy of the extinct steppe bison, Bison priscus from the early Holocene of northern Yakutia, Russia (pdf), Quaternary International, 406, Part B, pp.94-110.
- Michio Kawada, 1932, On Bison occidentalis Lucas from Manchuria on J-STAGE
- Hasegawa, Y.; Okumura, Y.; Tatsukawa, H. (2009). "First record of Late Pleistocene Bison from the fissure deposits of the Kuzuu Limestone, Yamasuge，Sano-shi，Tochigi Prefecture，Japan" (PDF). Bull.Gunma Mus.Natu.Hist. Gunma Museum of Natural History and Kuzuu Fossil Museum (13): 47–52. Retrieved 2018-12-03.