The giant short-faced bear (Arctodus) is an extinct bear that inhabited North America during the Pleistocene epoch from about 2.5 Mya until 12,800 years ago. There are two recognized species: Arctodus pristinus and Arctodus simus, with the latter considered one of the largest known terrestrial mammalian carnivores.
Naming and etymology[]
The name short-faced bear derives from the shape of their skulls, which appear to have a proportionally short snout compared to other bears; this characteristic is also shared by its extant relative the spectacled bear. However, this apparent shortness is an optical illusion caused by their deep snouts and short nasal regions. The scientific name of the genus, Arctodus, derives from the Greek language and means "bear tooth".
Taxonomy, classification and evolution[]
Arctodus belongs to a group of bears known as the Tremarctinae (short-faced bears), which appeared in the Americas during the earliest parts of the late Miocene epoch in the form of Plionarctos, a genus considered ancestral to Arctodus, Arctotherium and the modern spectacled bear (Tremarctos ornatus).
Arctodus pristinus evolved first, and was largely restricted to the Early Pleistocene of the more heavily forested eastern United States, with a temporal range between 2.5mya and 300kya. Arctodus simus emerged between 1.4mya and 780kya, with finds being concentrated in the western United States. During the Rancholabrean faunal stage, A. simus took over the now extinct A. pristinus' eastern range, and could also be found in Canada and Mexico. Arctodus simus went extinct around 12,800 years ago.