广西扶绥岩亮洞早更新世独角犀年龄结构的分析

Age Profiles of Rhinoceros from the Yanliang Cave, Fusui County, Guangxi, South China

岩亮洞是广西扶绥地区最近新发现的早更新世巨猿化石点,经过初步发掘,采集到了丰富的巨猿材料及大量伴生的哺乳动物化石。引人注目的是其中犀类化石居多,包括146颗完整的牙齿及十多件头后骨骼化石,从形态特征判断,这些犀类化石应属于独角犀的一新种Rhinoceros fusuiensis。岩亮洞巨猿动物群中的独角犀以种群丰度最大而不同于其他已知东亚地区的巨猿动物群中的独角犀类材料。本文从犀类牙齿的主尖釉质层、齿质暴露程度、咀嚼面的磨蚀程度等方面对岩亮洞独角犀的年龄结构进行了研究。该死亡群中至少有4头幼年个体、5头青年个体、5头成年个体和1头老年个体。依据牙齿磨蚀程度和牙齿萌出顺序对年龄结构的分析及统计显示,其中青年个体和成年个体最多,幼年个体次之,老年个体最少,其死亡的原因不是通常意义上磨耗型死亡,突发性的灾害可能是造成这种死亡年龄分布的主要原因。

The Gigantopithecus fauna recently discovered in the Yanliang Cave, Fusui County, Chongzuo Municipality, Guangxi Autonomous Region, South China, consists of abundant Gigantopithecus remains including mandibles and a large variety of fossil mammals. The most conspicuous large mammalian remains include 146 complete isolated teeth and a dozen postcrania of Rhinocerotidae, belonging to Rhinoceros fusuiensis based on morphological analysis. The Yanliang Gigantopithecus fauna is characterized by the presence of several Neogene relic taxa such as Megantereon, Hesperotherium and ＂Dicoryphochoerus＂, and many primitive species from the Quaternary such as Pachycrocuta licenti, Ailuropoda microta, Tapirus sanyuanensis, Typhlomys intermedius, Niviventer preconfucianus and Leopoldamys edwardsioides. The geological age is estimated to be Early Pleistocene based on fauna and stratigraphic correlation. Age profiles of these Rhinoceros remains were determined on the basis of tooth attrition analysis and checking the exposure of enamel and dentine. Results show that there are at least five adults and five sub-adult individuals, which were the dominant elements in the fossil assemblage suggesting their death was due to disaster.