Belongs within: Carnivora.
Contains: Ursus.
The Ursidae, bears, are a family of relatively large carnivorans found primarily in Eurasia and the Americas. The living forms are plantigrade and omnivorous (in the case of the giant panda Ailuropoda melanoleuca primarily herbivorous whereas the polar bear Ursus maritimus is primarily carnivorous). Among recent species, the largest is U. maritimus; the smallest is the sun bear Helarctos malayanus. The spectacled bear Tremarctos ornatus is the only living species found in South America, where it mostly inhabits the Andes of the northwestern part of the continent. The sloth bear Melursus ursinus is a medium-sized species with a long, thick snout found on the Indian subcontinent.
The extinct subfamilies Amphicynodontinae and Hemicyoninae were longer-faced (and often smaller) than modern bears; the Hemicyoninae in particular were superficially similar to dogs.
Synapomorphies (from Flynn et al. 1988): Malleus with tensor tympani insertion process reduced or lost; two upper and three lower molars; upper molars enlarged by expansion of metaconule; protocone and metaconule of upper molars forming longitudinal crest occluding with enlarged talonid cusps of lower molars; M2 developing posteriorly projecting platform occluding with M3; M2 trigonid lacking paraconid. Internal carotid artery folded intracranially within inferior petrosal sinus.
<==Ursidae
| i. s.: Tremarctotherium simumFP64
| Euarctos americanusGM71
| Plesiocyon Schlosser 1887SM93
|--Amphicynodontinae [Amphicynodontidae]MJ11
| | i. s.: Parictis Scott 1893MJ11, SM93
| | `--*P. primaevus Scott 1893BT96
| | Drassonax Galbreath 1953BT96
| | `--*D. harpagops Galbreath 1953BT96
| | Campylocynodon Chaffee 1954BT96
| | `--*C. personi Chaffee 1954BT96
| |--Amphicynodon Filhol 1881RDT09, BT96
| | |--*A. velaunusBT96
| | |--A. chardiniBT96
| | |--A. major (Clark & Guensburg 1972) [=Parictis (Subparictis) major]BT96
| | |--A. mongoliensisBT96
| | `--A. teilhardiFF06
| `--+--+--AllocyonRDT09
| | `--Pachycynodon gryeiRDT09, T76
| `--HemicyoninaeMJ11
| |--Cephalogale Jourdan 1862RDT09, SM93
| `--HemicyonDW04
| |--H. johnhenryi [=Phoberocyon johnhenryi]V91
| `--H. teilhardiDW04
`--UrsinaeC96
| i. s.: Ursavus elmensisJC07, B84
| AilurarctosJC07
|--+--Ailuropoda [Ailuropodidae, Ailuropodinae, Ailuropodini]FS15
| | |--A. baconiJC07
| | |--A. melanoleuca (David 1869)H07
| | |--A. microtaJC07
| | `--A. wulingshanensisJC07
| `--+--Indarctos atticusSA06, FF06
| `--Agriotherium Wagner 1837SA06, D07
| |--A. africanumS78
| |--A. gregoryiD07
| |--A. inexpetansDW04
| |--A. schneideriD07
| `--A. sivalensisD07
`--+--+--Tremarctos Gervais 1855FS15, C57 [incl. Nearctos Gray 1876C57; Tremarctinae]
| | |--*T. ornatus (Cuvier 1825) (see below for synonymy)C57
| | `--T. floridanusFS15
| `--+--ArctodusFS15
| | |--A. pristinusV91
| | `--A. simusFS15
| `--ArctotheriumFS15
| |--A. tarijenseFS15
| `--A. wingeiFS15
`--+--Helarctos malayanusFS15 [=Ursus malayanusBP87]
`--+--Melursus ursinusFS15
`--UrsusFS15
Inorganic: Helarctos malayanus protominilorientalus Okamura 1987O87
*Tremarctos ornatus (Cuvier 1825) [=Ursus ornatus, Helarctos ornatus, Nearctos ornatus; incl. Ursus frugilegus Tschudi 1844, U. fructilegus, Tremarctos lasallei María 1924, T. ornatus majori Thomas 1902, U. nasutus Sclater 1868, U. ornatus thomasi Hornaday 1911]C57
*Type species of generic name indicated
References
[BT96] Baskin, J. A., & R. H. Tedford. 1996. Small arctoid and filiform carnivorans. In: Prothero, D. R., & R. J. Emry (eds) The Terrestrial Eocene–Oligocene Transition in North America pp. 486–497. Cambridge University Press.
[B84] Bunnell, F. 1984. The bear family. In: Macdonald, D. (ed.) All the World’s Animals: Carnivores pp. 78–79. Torstar Books Inc.: New York.
[BP87] Burton, J. A., & B. Pearson. 1987. Collins Guide to the Rare Mammals of the World. Collins: London.
[C57] Cabrera, A. 1957. Catalogo de los mamiferos de America del Sur. I (Metatheria—Unguiculata—Carnivora). Revista del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” e Instituto Nacional de Investigacion de Las Ciencias Naturales, Ciencias Zoológicas 4 (1): 1–307.
[C96] Campbell, N. A. 1996. Biology 4th ed. The Benjamin/Cummings Publishing Company, Inc.: Menlo Park (California).
[DW04] Deng T., Wang X., Ni X. & Liu L. 2004. Sequence of the Cenozoic mammalian faunas of the Linxia Basin in Gansu, China. Acta Geologica Sinica (English Edition) 78 (1): 8–14.
[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.
[FS15] Faurby, S., & J.-C. Svenning. 2015. A species-level phylogeny of all extant and late Quaternary extinct mammals using a novel heuristic-hierarchical Bayesian approach. Molecular Phylogenetics and Evolution 84: 14–26.
[FF06] Finarelli, J. A., & J. J. Flynn. 2006. Ancestral state reconstruction of body size in the Caniformia (Carnivora, Mammalia): the effects of incorporating data from the fossil record. Systematic Biology 55 (2): 301–313.
[FP64] Fisher, J., & R. T. Peterson. 1964. The World of Birds: A comprehensive guide to general ornithology. Macdonald: London.
[GM71] Goodman, M., & G. W. Moore. 1971. Immunodiffusion systematics of the primates I. The Catarrhini. Systematic Zoology 20 (1): 19–62.
[H07] Hooker, J. J. 2007. Bipedal browsing adaptations of the unusual Late Eocene-earliest Oligocene tylopod Anoplotherium (Artiodactyla, Mammalia). Zoological Journal of the Linnean Society 151 (3): 609–659.
[JC07] Jin, C., R. L. Ciochon, W. Dong, R. M. Hunt, Jr, J. Liu, M. Jaeger & Q. Zhu. 2007. The first skull of the earliest giant panda. Proceedings of the National Academy of Sciences of the USA 104 (26): 10932–10937.
[MJ11] Meredith, R. W., J. E. Janečka, J. Gatesy, O. A. Ryder, C. A. Fisher, E. C. Teeling, A. Goodbla, E. Eizirik, T. L. L. Simão, T. Stadler, D. L. Rabosky, R. L. Honeycutt, J. J. Flynn, C. M. Ingram, C. Steiner, T. L. Williams, T. J. Robinson, A. Burk-Herrick, M. Westerman, N. A. Ayoub, M. S. Springer & W. J. Murphy. 2011. Impacts of the Cretaceous terrestrial revolution and KPg extinction on mammal diversification. Science 334: 521–524.
[O87] Okamura, C. 1987. New facts: Homo and all Vertebrata were born simultaneously in the former Paleozoic in Japan. Original Report of the Okamura Fossil Laboratory 15: 347–573.
[RDT09] Rybczynski, N., M. R. Dawson & R. H. Tedford. 2009. A semi-aquatic Arctic mammalian carnivore from the Miocene epoch and origin of Pinnipedia. Nature 458: 1021–1024.
[SA06] Salesa, M. J., M. Antón, S. Peigné & J. Morales. 2006. Evidence of a false thumb in a fossil carnivore clarifies the evolution of pandas. Proceedings of the National Academy of Sciences of the USA 103: 379–382.
[S78] Savage, R. J. G. 1978. Carnivora. In: Maglio, V. J., & H. B. S. Cooke (eds) Evolution of African Mammals pp. 249–267. Harvard University Press: Cambridge (Massachusetts).
[SM93] Stucky, R. K., & M. C. McKenna. 1993. Mammalia. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 739–771. Chapman & Hall: London.
[T76] Tedford, R. H. 1976. Relationship of pinnipeds to other carnivores (Mammalia). Systematic Zoology 25 (4): 363–374.
[V91] Valkenburgh, B. van. 1991. Iterative evolution of hypercarnivory in canids (Mammalia: Carnivora): evolutionary interactions among sympatric predators. Paleobiology 17 (4): 340–362.