Agriotherium

Agriotherium
Temporal range: 13.6–2.5 Ma
Teeth
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Superfamily: Arctoidea
Family: Ursidae
Subfamily: †Agriotheriinae[1]
Kretzoi, 1929
Genus: †Agriotherium
Wagner, 1837
Type species
†Agriotherium sivalensis
Falconer & Cautley, 1836
Species[2]

†A. myanmarensis (Ogino et al., 2011)
†A. insigne (Gervais, 1859)
†A. inexpetans (Qiu et al., 1991)
†A. palaeindicus (Lydekker, 1878)
†A. sivalensis (Falconer & Cautley, 1836)
†A. africanum (Hendey, 1972)
†A. coffeyi (Dalquest, 1986)
†A. gregoryi (Frick, 1926)
†A. schneideri (Sellards, 1916)

Agriotherium is an extinct genus of bears whose fossils are found Miocene through Pleistocene-aged strata of North America, Europe, Africa, and Asia, living from ~13.6–2.5 Ma, existing for approximately 11.1 million years. Materials of the late surviving A. africanum from Africa has suggested that A. africanum died out soon during the early Gelasian.

Morphology

Mandible

Agriotherium was about 2.7 metres (9 ft) in body length and weighed around 900 kilograms (1,980 lb), making it larger than most living bears. Except for the extinct subspecies of the 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 close to those of most large ungulates (bovines, cervids, camelids, and others), it is probable that Agrotherium could have preyed on these. Agriotherium also likely scavenged, and would not have been hesitant about stealing kills from such animals as the sabertooth cat Amphimachairodus, with whom it shared territory in both China and North America, and the feliform Barbourofelis, which it lived alongside in Texas, as evidenced by fossil deposits at Coffee Ranch.[3][4]

Body mass

Two specimens were examined by Legendre and Roth for body mass.[5]

  • Specimen 1: 79.3 kg (175 lb)
  • Specimen 2: 652.6 kg (1,440 lb)

Bite strength

A 2011 estimate that compared the bites of a few selected bears, both extant and extinct, concluded that Agriotherium had the strongest bite-force of any mammalian land-predator yet estimated.[6]

Fossil distribution

Sites and age of specimens:

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

  1. ↑ McLellan, B.; Reiner, D.C. (1992). "A review of bear evolution". International Association for Bear Research and Management. 9 (1): 85–96. doi:10.2307/3872687.
  2. ↑ Ogino, Shintaro, Naoko Egi, and Masanaru Takai. "New species of Agriotherium (Mammalia, Carnivora) from the late Miocene to early Pliocene of central Myanmar." Journal of Asian Earth Sciences 42.3 (2011): 408-414.
  3. ↑ Antón, Mauricio (2013). Sabertooth. Bloomington, Indiana: University of Indiana Press. pp. 53–54. ISBN 9780253010421.
  4. ↑ Turner, Alan (1997). The Big Cats and their fossil relatives. New York: Columbia University Press. p. 201. ISBN 0-231-10228-3.
  5. ↑ S. Legendre and C. Roth. 1988. Correlation of carnassial tooth size and body weight in recent carnivores (Mammalia). Historical Biology 1(1):85–98
  6. ↑ "Ancient bear had the strongest bite". BBC News.
  7. ↑ 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. 18: 1–20. doi:10.1080/08912960500476366.
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