江苏泗洪下草湾中中新世脊椎动物群——8. Dorcatherium(Tragulidae,Artiodactyla)

本文记述了江苏泗洪下草湾动物群中最常见的一种化石,羚鼷鹿(Dorcatherium).材料包括六段破碎颌骨、若干肢骨和四百余颗单个牙齿.根据齿冠低、上颊齿齿带弱、下臼齿∑形结构清楚等特点,将它订为—新种:东方羚鼷鹿(Dorcatherium orientale sp. nov.).其地质时代大约相当于欧洲的 MN4.文中还讨论了鼷鹿科的分类问题,指出在牙齿构造上有三个类群:Dorcatherium, Dorcabune 和现生鼷鹿.

THE ARAGONIAN VERTEBRATE FAUNA OF XIACAOWAN, JIANGSU--8. DORCATHERIUM (TRAGULIDAE, ARTIODACTYLA)

In their preliminary report on the Xiacaowan vertebrate fauna in 1983, Li Chuankui et al. listed two unnamed Dorcatherium species, based on 4 jaw fragments and a few isolated teeth. Since then, the junior author of the present paper has intermittently visited this site with the aim to collect as many fossils as possible. As a result, she not only succeeded in finding rich material from the most fossiliferous site, Songlinzhuang, but also collected some specimens from Zhengji, a new locality, about 2 km northeast to the first site. Now the specimens identified as belonging to Dorcatherium amount to 6 jaw fragments, 370 isolated teeth, about one hundred fragmentary teeth and some foot bones. They are the most frequently uncountered fossils in the Xiacaowan fauna, and Dorcatherium, therefore, seems to be the most representative animal of that fauna. Detailed study of the sample does not seem to favour the viewpoint of Li et al. that there existed two Dorcatherium species. We failed to find a way to further divide the sample into groups. In the following we deal with the whole sample as of one species and describe the teeth in an order from the teeth whose loci determination is more reliable to the teeth whose loci are less certain, since the majority of the teeth are isolated ones.