Ailuropoda baconi
Ailuropoda baconi is an extinct species or subspecies of bear known from cave deposits in South China, Laos, Vietnam, Myanmar, and Thailand spanning the Middle and Late Pleistocene and into the Middle Holocene. It is the direct ancestor of the living giant panda. It was preceded by A. wulingshanensis. Its distinctiveness from the living giant panda is disputed, and it has been argued that it should be treated as a paleosubspecies of the giant panda as ''A. melanoleuca baconi.''
Description
Members of A. ''baconi were the largest members of the giant panda lineage, considerably larger than the preceding species A. wulingshanensis, and somewhat larger than the living giant panda. The average body mass of A. baconi'' some localities was estimated in a 2024 study at approximately, with some individuals estimated to exceed, compared to the around and average weight estimated for captive mature male and female giant pandas, respectively. The zygomatic arches of the skull are very well developed, though the sagittal crest at the top of the skull is only moderately developed.
Palaeoecology
Unlike the living giant panda, which is confined to mountainous areas higher than above sea level, A. ''baconi ranged widely across southern China and into southeast Asia, from altitudes below to above. δ13C values derived from A. baconi specimens indicate that it had a preference for open forest habitat. Its diet was probably broader than that of the primarily bamboo consuming giant panda, though it was still predominantly plant based. Ailuropoda baconi was a titular member of the "Ailuropoda-Stegodon fauna" in southern China in the Middle-Late Pleistocene, alongside species such as the giant tapir Tapirus augustus,the Asian elephant the extinct elephant-relative Stegodon orientalis, the Sumatran rhinoceros , the extinct rhinoceros Rhinoceros sinensis '', wild boar '','' muntjac, water buffalo, sika deer, the extinct orangutan species Pongo weidenreichi, gibbons, tigers, and the extinct cave hyena.
Extinction
Ailuropoda baconi saw a dramatic range collapse from the end of the Pleistocene to the middle Holocene, becoming restricted to upland areas above, where it evolved into the modern giant panda. The morphological transition between A. baconi and the living giant panda may be due to ecological changes as a result of the restriction to mountainous environments.