Like living animals, fossil remains of once-living animals are classified and grouped according to their relationships to each other and to their ancestors.
The bear family, Ursidae occupied North America for the last 37 million years; present bear diversity is much reduced compared to its fossil record.
The fossil record for bears is extensive. (Li et al 2007)
Plionarctosis the first tremarctine (the short-faced bears) (Tedford & Martin 2001, Li et al 2007)
The first Arctodus fossils are found in Pleistocene rocks between 1.8 million and 300,000 years ago. (Hunt 1997)
Arctodus, the extinct short-faced bear, and Tremarctos, the living spectacled bear, are the last of the tremarctine lineage.
Arctodus became extinct around 11,400 years ago (uncalibrated Carbon 14 years) or about 13,000 calendar years (calibrated)
Describer (Date): E.D. Cope 1879 for Arctodus simus
Family: Ursidae (bears)
Subfamily: Tremarctinae (the "running bears")
Species: Arctodus simus - short-faced bear (extinct)
Species: Arctodus pristinis - lesser short-faced bear (extinct)
Agnarsson et al (2010)
Figueirido et al (2010)
Kurtén & Anderson (1980)
McKenna and Bell (1997)
Tedford & Martin (2001)
Wayne et al (1989)
Li et al (2007)