云南元谋古猿动物群化石埋藏学

云南元谋小河-雷老一带含古猿新近系（上第三系）是一套紫红色含砾细砂-粉砂岩,夹有多层黄色砂砾石层。化石埋藏学研究及含化石层岩性特征、组合及沉积构造表明,该层以山前洪积堆积为主,并有发育的扇上河道沉积。通过30余个发掘地点化石野外埋藏资料及数千件化石标本的分析鉴定,化石埋藏类型有两种,埋藏Ⅰ型的化石数量稀少、保存完整,赋存在扇体细粒沉积物中;理藏Ⅱ型化石保存丰富但相当残破,赋存在粗粒沉积的扇上河道各个部位。化石埋藏类型与古气候、古生态有着密切的关系,化石埋藏特征表明该区自然环境分带已形成。元谋古猿动物群的生存时代是一个从森林向草原-灌丛环境过渡的动荡时期。

Taphonomy of the Hominoid Fauna in the Yuanmou Basin, Yunnan

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.