Taphonomy of the Hominoid Fauna in the Yuanmou Basin, Yunnan
ZHANG Yunxiang,ZHENG Liang,JI Xueping,ZHANG Jiahua1) The Key Laboratory of Continental Dynamics,Ministry of Education of China,Department of Geology,Northwest University,Xi''''an,7100692) Yunnan Institute of Cultural Relics and Archaeology,Kunming,6501183
Abstract:The Neogene deposits with hominoid fossils in the Xiaohe - Leilao area, Yuanmou, Yunnan, are a se-quence of purple pebbly fine sandstone-siltstone with several yellow gravel beds. Taphonomic study and litho-logical characteristics, assemblages and sedimentary structures of the fossil-bearing bed show that this fossil-bearing bed consists dominantly of piedmont diluvial deposits with well-developed fan channel deposits. On the basis of an analysis of a few thousand pieces of mammalian fossils and taphonomic data from more than 30 exca-vation sites, two taphonomic types are identified. Fossils of type 1 are scarce and completely preserved in fine sediments of the fan. Fossils of type 2 are abundant but rather broken and are localized in yellow coarse sedi-ments of fan channels. The taphonomic types are closely related to the palaeoclimate and palaeoecology. The taphonomic characteristics of the fossils suggest that the environmental zonation in the area had been formed. The period when the Yuanmou hominoid fauna lived was an unrest, transitional one from the forest to bushveld environment.