Plionarctos is an extinct genus of bear endemic to North America from the Miocene to the Pliocene,[2] ~10.3—3.3 Mya, existing for about 7 million years.
| Plionarctos Temporal range:
| |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Ursidae |
| Subfamily: | Tremarctinae |
| Genus: | †Plionarctos Frick, 1926[1] |
| Type species | |
| †Plionarctos edensis Frick, 1926
| |
| Species | |
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†P. harroldorum Tedford & Martin, 2001[2] | |
Indarctos (10.7—9.2 Mya) preceded Plionarctos by only a few thousand years and was a contemporary of that bear and shared its habitat. Plionarctos preceded and was also contemporary with Tremarctos floridanus (4.9 million — 11,000 years ago) and shared its habitat. Plionarctos is the oldest known genus within the subfamily of the short-faced bears (Tremarctinae), and is believed to be ancestral to the clade.
Fossil distribution
editSites and specimen ages:
- Ile de Ratonneau Breccia, Provence, France about ~800,000—100,000 years ago [citation needed]
- Fort Green Mine, Polk County, Florida paleontological sites about 10.3—4.9 Mya
- Taunton site, Adams County, Washington (P. harroldorum) about 4.9—1.8 Mya (Plionarctos harroldorum)
- Pipe Creek Sinkhole, Grant County, Indiana (P. edensis) about 10.3—1.8 Mya
- Palmetto Mine, Polk County, Florida 7.9—7.8 Mya
- Gray Fossil Site, Washington County, Tennessee about 7.0-4.5 Mya
References
edit- ^ Frick, Childs (1926). "The Hemicyoninæ and an American Tertiary Bear". Bulletin of the American Museum of Natural History. 56 (1): 111–119. hdl:2246/1321.
- ^ a b Tedford, Richard H.; Martin, James (2001). "Plionarctos, a tremarctine bear (Ursidae: Carnivora) from western North America". Journal of Vertebrate Paleontology. 21 (2): 311–321. doi:10.1671/0272-4634(2001)021[0311:PATBUC]2.0.CO;2. JSTOR 20061955. S2CID 130061851.