Ailurarctos

Ailurarctos
Temporal range: Late Miocene
Paleoart of two Ailurarctos
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Tribe: Ailuropodini
Genus: Ailurarctos
Qi et al., 1989
Type species
Ailurarctos lufengensis
Qi et al., 1989
Species

A. lufengensis Qi et al., 1989
A. yuanmouenensis Zong, 1997

Ailurarctos ("cat bear") is an extinct genus of panda from the Late Miocene of China, some 8 million years ago. Fossils attributed to Ailurarctos lufengensis, including isolated teeth discovered in the Lufeng Bsain of Yunnan Province, represent some of the earliest evidence of the giant panda lineage in China.

Different teeth structures in the Ailuropoda lineage indicate a mosaic evolution during the past 2 million years. Like modern giant panda Ailuropoda melanoleuca, Ailurarctos had a false thumb (pseudothumb) that allowed it to grip bamboo. The earlist known pseudothumb is from the fossil of Ailurarctos discovered in Yunnan, China, suggesting that the panda's specialized bamboo diet goes back to as early as 6 to 7 million years ago. Compared to living giant pandas, Ailurarctos lack the sharp inward distal hook in their radial sesamoids.