作者：王世骐, 李春晓, 张晓晓,江左其杲, 叶 捷, 李 录, 李福昌
摘要：中国新近纪哺乳动物年代序列的研究已经有了很大的进展，然而，山旺期早期(20~18 Ma)的哺乳动物化石记录却非常缺乏。报道了新疆维吾尔自治区准噶尔盆地北缘吃巴尔我义东地点索索泉组上部山旺期早期(18.6 Ma)的化石，包括早期欧亚大陆象类和早期鹿科动物。其中，嵌齿象的M2第二脊具有发育良好的副齿柱三叶，因此可以鉴定为原互棱齿象未定种(Protanancus sp.), 属于铲齿象科(Amebelodontidae), 形态上比山旺期晚期的短吻原互棱齿象(P. brevirostris)和托氏原互棱齿象(P. tobieni)原始。而鹿科的鹿角化石具有比较小但高的掌状部分，因此被鉴定为皇冠鹿未定种(Stephanocemas sp.), 属于柄杯鹿亚科(Lagomerycinae)。通过形态学对比认为，该鹿角在系统演化上非常接近皇冠鹿和柄杯鹿(Lagomeryx)的分化位置，并与原始的卢瓦鹿(Ligeromeryx)相去不远。以往的研究证明，长鼻类和鹿科动物在中国出现在谢家期和山旺期之交，因此，巴尔我义东地点原互棱齿象和皇冠鹿的发现首次提供了在这一地区寻找长鼻类和鹿类的重要线索，并且有可能建立山旺阶的下界层型。新材料的层位过去在中国地区很少发现化石，因此有助于深入理解中国山旺期早期的哺乳动物面貌。
A record of the early Protanancus and Stephanocemas from the North of the Junggar Basin, and its implication for the Chinese Shanwangian
WANG Shi-Qi, LI Chun-Xiao, ZHANG Xiao-Xiao, JIANGZUO Qi-Gao, YE Jie, LI Lu, LI Fu-Chang
Abstract The Chinese Neogene mammalian fauna sequence has been well established, except for a gap in the early Shanwangian (~20–18 Ma) for which there are few known records of fossil mammals in China. Hereby we report on a newly discovered fossiliferous horizon from the upper part of the Suosuoquan Formation (18.6 Ma), Chibaerwoyi East locality, northern Junggar Basin, Xinjiang Uyghur Autonomous Region. In this locality, the occurrences of an early Eurasian proboscidean and an early cervid clearly indicate an early Shanwangian Age of the Early Miocene. The proboscidean check teeth are characterized by the well-developed posttrite trefoils on the second lophs. It was identified as Protanancus sp. (Amebelodontidae), which is morphologically more primitive than the late Shanwangian P. brevirostris and P. tobieni. The cervid antler is characterized by the relatively small yet high palm of the antler and relatively short tines. It was identified as Stephanocemas sp. (Lagomerycinae), which is phylogenetically very close to the dichotomy of Stephanocemas and Lagomeryx, and is morphologically close to the more ancestral Ligeromeryx. Previous studies have shown that both proboscideans and cervids occurred at the Xiejian/Shanwangian transition period. Therefore, the new materials of Protanancus sp. and Stephanocemas sp. give important clues to the first appearance data of proboscideans and cervids in this area, which facilitates establishing the lower stratotype of the Chinese Shanwangian. In conclusion, the new findings represent a rarely known stage of mammalian biostratigraphy in China and are helpful for understanding the faunal succession during the early Chinese Shanwangian.
Key words Junggar Basin, Early Miocene, Suosuoquan Formation, Shanwangian, Protanancus, Stephanocemas
