New discovery of a late Middle Pleistocene mammalian fauna in Ganxian Cave, Southern China

This report describes fossils recovered from Ganxian Cave in 2008 and 2018 by the Natural History Museum and Anthropology Museum of Guangxi. The cave sedimentary fill yielded rich mammalian fossils consisting mainly of isolated teeth of medium- to large-sized mammals (Primates, Proboscidea, Perissodactyla, Carnivora, Rodentia, Artiodactyla) of typical ‘Ailuropoda-Stegodon’ fauna, (e.g. Stegodon orientalis, Ailuropoda baconi, Pongo weidenreichi, Tapirus sinensis, Megatapirus augustus, Crocuta ultima), and more numerous extant species belonging to 28 taxa in total. The biochronological age of the fauna agreed with the age estimates obtained using Uranium–series and coupled ESR/U-series dating. Collectively, these results indicate a Ganxian fossil age range of 168.9 ± 2.4 ka to 362 ± 78 ka and establish Ganxian Cave as one of the most precisely dated Middle Pleistocene fossil sites in southern China. Comparison of Ganxian fauna with Pleistocene fossil records of the well-documented faunas of southern China and southeast Asia indicates that the Asian elephant (Elephas maximus) probably first appeared in Ganxian Cave. Paleoenvironmental reconstruction-based analysis of the large mammalian fossil assemblage from Ganxian Cave indicates that during the late Middle Pleistocene, the habitat consisted mainly of forests with some open areas and the climate was warm and humid.