Agriotherium
| Agriotherium Temporal range: Late Miocene–Pleistocene | |
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| Teeth | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Superfamily: | Arctoidea |
| Family: | Ursidae |
| Subfamily: | Ursinae |
| Tribe: | Ursavini |
| Genus: | †Agriotherium Wagner, 1837 |
| Species | |
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Agriotherium is an extinct genus of Ursidae of the Miocene through Pleistocene epochs, with fossils found in Neogene strata of North America, Europe, Africa, and Asia, living from ~13.6–2.5 Ma, existing for approximately 11.1 million years.
Taxonomy
Agriotherium was named by Wagner (1837). It was assigned to Agriotheriini by Chorn and Hoffman (1978); to Hemicyoninae by Qiu et al. (1991); to Ursavini by Hunt (1998); to Ursidae by Wagner (1837), Carroll (1988) and Salesa et al. (2006), and Ursinae by Krause et al. 2008. [1][2][3][4]
Morphology
Agriotherium was about 2.7 metres (9 ft) in body length, making it larger than most living bears. Except for the extinct subspecies of modern polar bear Ursus maritimus tyrannus and Arctotherium, Agriotherium was along with the short-faced bear, Arctodus simus the largest member of terrestrial Carnivora. It had dog-like crushing teeth. Its primary diet was carnivorous and secondary was omnivorous possibly classifying this animal as mesocarnivore. With a body mass greater than most large ungulates (horses, bovines, camelids, and rhinoceroses), it is probable that Agrotherium could have preyed on these.
Body mass
Two specimens were examined by Legendre and Roth for body mass.[5]
- Specimen 1: 79.3 kg (170 lb)
- Specimen 2: 652.6 kg (1,400 lb)
Bite strength
A recent estimate that compared the bites of a few selected bears, both extant and extinct ones, concluded that Agriotherium had the strongest bite and so far the strongest bite-force of any mammalian land-predator, yet estimated.[6]
Fossil distribution
Sites and age of specimens:
- American Cyanimid Company site, Bone Valley Formation, Polk County, Florida ~13.7—11.6 Ma.
- Venta del Moro, Spain ~9–5.3 Ma.
- Lang. E Quarry, South Africa ~5.3–3.6 Ma.
- Carlin High Quarry, Elko County, Nevada ~23–5.3 Ma.
- Vialette, Haute Loire, France ~3.2–2.5 Ma.
- Middle Awash, Ethiopia ~11.6–3.6 Ma.
Agriotherium ranged widely; fossils of four or more species have been found in Europe, India, China, North America and South Africa. It is the only ursoid known to have colonized sub-Saharan Africa (amphicyonid "bear dogs" also reached the area).[7]
References
- ↑ Chorn, J.; Hoffmann, R. S. (1978). "Ailuropoda melanoleuca". Mammalian Species 110: 1–6. doi:10.2307/3503982. JSTOR 3503982.
- ↑ Hunt, R. M. (1998). "Ursidae". In Jacobs, Louis; Janis, Christine M.; Scott, Kathleen L. Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate like Mammals. Cambridge, UK: Cambridge University Press. pp. 174–195. ISBN 0-521-35519-2.
- ↑ Krause, J.; Unger, T.; Noçon, A.; Malaspinas, A.; Kolokotronis, S.; Stiller, M.; Soibelzon, L.; Spriggs, H.; Dear, P. H.; Briggs, A. W.; Bray, S. C. E.; O'Brien, S. J.; Rabeder, G.; Matheus, P.; Cooper, A.; Slatkin, M.; Pääbo, S.; Hofreiter, M. (2008-07-28). "Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary". BMC Evolutionary Biology 8: 220. doi:10.1186/1471-2148-8-220. PMC 2518930. PMID 18662376.
- ↑ Salesa, M. J.; Antón, M; Peigné, S; Morales, J (January 2006). "Evidence of a false thumb in a fossil carnivore clarifies the evolution of pandas". Proc. Natl. Acad. Sci. U.S.A. 103 (2): 379–82. doi:10.1073/pnas.0504899102. PMC 1326154. PMID 16387860.
- ↑ S. Legendre and C. Roth. 1988. Correlation of carnassial tooth size and body weight in recent carnivores (Mammalia). Historical Biology 1(1):85–98
- ↑ "Ancient bear had the strongest bite". BBC News.
- ↑ Howell, F. Clark; Garcia, Nuria (December 2007). "Carnivora (Mammalia) From Lemudong’o (Late Miocene: Narok District, Kenya)" (PDF). Kirtlandia (Cleveland Museum of Natural History) 556: 121–139. Retrieved 2009-10-15.
Sources
- Dalquest, W. W. (1986). "Lower Jaw and Dentition of the Hemphillian Bear, Agriotherium (Ursidae), with the Description of a New Species". Journal of Mammalogy 67 (4): 623–631. doi:10.2307/1381124. JSTOR 1381124.
- Miller, W. E.; Carranza-Castañeda, O.; Carranza-Castaneda, Oscar (1996). "Agriotherium schneideri from the Hemphillian of Central Mexico". Journal of Mammalogy 77 (2): 568–577. doi:10.2307/1382830. JSTOR 1382830.
- Petter, G.; Thomas, H. (1986). "Les Agriotheriinae (Mammalia, Carnivora)néogènes de l'Ancien Monde presence du genre Indarctos dans la faune de Menacer (ex−Marceau), Algérie". Geobios 19: 573–586. doi:10.1016/s0016-6995(86)80055-9.
- Sorkin, B. (2006). "Ecomorphology of the giant short-faced bears Agriotherium and Arctodus". Historical Biology: A Journal of Paleobiology 18: 1–20. doi:10.1080/08912960500476366.