Bears are a small group of mostly large mammals, with 8 species in 5 genera (Ursus, Tremarctos, Melursus, Helarctos, and Ailuropoda). Although Ursidae is not diverse, species in this family are widespread and culturally significant to human populations throughout their range.
- Flynn, J., J. Finarelli, S. Zehr, J. Hsu, M. Nedbal. 2005. Molecular phylogeny of the Carnivora (Mammalia): Assessing the impact of increased sampling on resolving enigmatic relationships. Systematic Biology, 54: 317-337.
- Nowak, R. 1991. Walker's Mammals of the World, Fifth Edition. Baltimore: The Johns Hopkins University Press.
- Vaughan, T., J. Ryan, N. Czaplewski. 2000. Mammalogy, 4th edition. New York: Saunders College Publishing.