中国境内大角鹿属的下颌骨厚度问题

ON THE MANDIBLE THICKNESS OF MEGACEROS IN CHINA

中国境内的大角鹿属是第四纪期间与人类化石相伴生的重要动物化石,过去常根据下颌骨厚度指数来鉴定大角鹿属各个种,现在看来,其角的形态变化,才是最重要依据.在中国大角鹿主要分布于北方地区,早期类型生存于温暖地带,晚期生存于稍寒冷一些地带.

The Megaceros fossils in China include the following species: Megaceros pachyosteus Young, 1932; M. ordosianus (Young), 1932; M. flabellatus Teilhard de Chardin, 1941; M. konwanlinensis Chow, Hu et Lee, 1978; M. sangganhoensis Wei, 1983; M. luochuanensis Xue, 1982; Sinomegaceros sp. Pei, 1958. The index of thickness of mandible was often used to compare different species of Megaceros in the past, the formula is as follows: The index of thickness of Meraceros in different Localities: Loc. 1 of Zhoukoudian, 69.1-91.1; Loc. 3 of Zhoukoudian, 69; Loc. 13 of Zhoukoudian, 70-80; Hexian, Anhui, 73-80; Xiangfen, Shanxi, 69; Huanxian, Gansu, 71. It seems to the author that the Megaceros from Loc. 1 of Zhoukoudian has a voluminous variation in the thickness of mandibles and the materials from other localities are just in the variation limit of the former. Thereforer, the author considers the index of thickness is meaningless. The change of the Megaceros principally shows on antler. It appeared with a small-sized antler in Early Pleistocene, which became well developed in Middle Pleistocene and small-sized in Late Pleistocene. The Megaceros distributed in North China. The Megaceros pachysteus distributed mainly in Beijing, Hebei, Shanxi, Shaanxi, Gansu, Shandong, Henan, Anhui but sometimes reached the lower Yangtze River. The Megaceros ordosianus distributed mainly in Hebei, Shanxi, Nei mongol, Gansu, Henan, Liaoning, Jilin and Heilongjiong.