Ursavus

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Ursavus
Temporal range: Oligocene–Miocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia
Superfamily: Arctoidea
Family: Ursidae
Subfamily: Ursinae
Tribe: †Ursavini[1][2]
Genus: †Ursavus
Type species
Ursavus brevirhinus
Species
  • U. brevirhinus
  • U. depereti
  • U. elmensis
  • U. orientalis
  • U. pawniensis
  • U. primaevus

Ursavus is an extinct genus of ursid carnivoran mammals that existed in North America, Europe, and Asia during the Miocene, living from ~23—5.3 Ma, existing for approximately 17.7 million years. The genus apparently dispersed from Asia into North America about 20 Ma, becoming the earliest member of the subfamily Ursinae in the New World.[3] Qiu points out that if a questionable 29 million-year-old specimen of Ursavus reported in North America is validated, Ursavus may have evolved in North America and dispersed westward into Asia. The higher number of fossils in Europe grading toward eastern Asia make the westward dispersal unlikely.

Ursavus was named by Schlosser (1899). It was assigned to Ursidae by Schlosser (1899) and R. L. Carroll (1988); and to Ursavini by R.M. Hunt (1998) and Jin et al. (2007).[1][4]

In life, the various species would have appeared as cat-sized,[5] superficially dog-like animals that were ground-dwelling omnivores or hypocarnivores.

U. elmensis, also known as the "dawn bear"[6] is generally taken to be the earliest undisputed bear species.[7][8]

Currently, only U. orientalis, from the Shanwang diatomite of Early Miocene China, is known from a complete skeleton.[5][9] Most other species are known from teeth and skull fragments.

Fossil distribution

Sites (not complete) and specimen ages:

  • Pawnee Buttes Site, Weld County, Colorado (U. pawniensis) ~23.03—5.3 Ma.
  • Shanwang diatomite, Shanwang, China (U. orientalis[9]) ~17-16 Ma.[5]
  • Pasalar site, Bursa, Turkey (U. primaevus) ~16—13.7 Ma.
  • Baigneaux-en-Beauc, Alsac, France (U. brevirhinus) ~16.9—16.0 Ma.
  • Hambach mine horizon 6C, Germany (U. elmensis) ~16.9—13.7 Ma.
  • Yost Farm Site, Saskatchewan, Canada (U. primaevus) ~16.3—13.6 Ma.
  • Myers Farm Site, Valentine Formation, Webster County, Nebraska (U. brevirhinus) ~16.3—13.6 Ma.
  • Lufeng site, Yunnan, China (U. depereti) ~7-6 Ma.[5]

In popular culture

Ursavus was featured briefly in the National Geographic documentary "Evolutions: Bear Necessities."

References

  1. ↑ 1.0 1.1 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. 
  2. ↑ C. Jin, R. L. Ciochon, W. Dong, R. M. Hunt, Jr., J. Liu, M. Jaeger, and Q. Zhu. 2007. The first skull of the earliest giant panda" Proceedings of the National Academy of Sciences 104:10932-10937
  3. ↑ Qiu Zhanxiang. 2003. Dispersals of Neogene Carnivorans between Asia and North America in Chapt 2, Bulletin of the American Museum of Natural History #279, pp18-31.
  4. ↑ R. L. Carroll. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York 1-698
  5. ↑ 5.0 5.1 5.2 5.3 Lindburg, Donald G. (2004). Giant Pandas: Biology and Conservation. University of California Press. p. 308. ISBN 9780520238671. p 46
  6. ↑ Derocher, Andrew E.; Ian Stirling (February 1989 (1990)). "Factors Affecting the Evolution and Behavioral Ecology of the Modern Bears". Bears: Their Biology and Management A Selection of Papers from the Eighth International Conference on Bear Research and Management 8: 189–204. JSTOR 3872919. 
  7. ↑ McLellan, Bruce (1994). "A REVIEW OF BEAR EVOLUTION". International Conference Bear Research and Management 9 (1): 85–96. doi:10.1080/08897077.2011.540477. 
  8. ↑ Derocher, A. E. & W. Lynch. 2012. Polar Bears: A Complete Guide to Their Biology and Behavior. The Johns Hopkins University Press, Baltimore
  9. ↑ 9.0 9.1 Yang, Hong; SHIPU YANG (December 1994). "The Shanwang fossil biota in eastern China: a Miocene Konservat-Lagerstätte in lacustrine deposits". Lethaia 27 (4): 345–354. doi:10.1111/j.1502-3931.1994.tb01585.x. 
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