纤细滇美龙(Dianmeisaurus gracilis Shang & Li,2015)新材料（英文）  

New information on Dianmeisaurus gracilis Shang & Li, 2015

作　　者：尚庆华[1] 李淳[1] 吴肖春 

机构地区：[1]中国科学院脊椎动物演化与人类起源重点实验室,中国科学院古脊椎动物与古人类研究所,北京100044 [2]加拿大自然博物馆,渥太华K1P6P4

出　　处：《古脊椎动物学报》2017年第2期145-161,共17页Vertebrata Palasiatica

基　　金：financially supported by the National Natural Science Foundation of China (no.41372028);Founds for Paleontology Fieldwork and Fossil Preparation,CAS to SQH and Canadian Museum of Nature (#RC09) to XCW~~

摘　　要：根据一件产自云南罗平中三叠世关岭组II段的新标本并结合产自相同地点和地层中的模式标本对纤细滇美龙(Dianmeisaurus gracilis Shang&Li,2015)进行了详细研究。原模式标本暴露其腹面,而新标本暴露其背面,两者互相补充提供了更完整、精确的纤细滇美龙解剖学信息。新材料揭示该种具有非常短小的吻部,眶前区的长度不仅短于眶后区长度,甚至短于眼眶的长度;外鼻孔小且位置靠前,即鼻孔前区的长度短于鼻孔后缘与眼眶前缘之间的距离;由两额骨构成的眼眶间隔非常狭窄,宽度小于顶骨平台宽度的1/3;额骨前后两端均具渐尖的突起;顶骨后部不收缩,顶骨平台后缘呈深V型。补充了新信息和包含更多属种(如Dawazisaurus)后的系统发育学分析支持了之前滇美龙和滇东龙互为姊妹群的结论,同时它们和马家山龙、滇肿龙、贵州龙和大洼子龙一起构成了一个仅由中国的属种组成的单系类群。与欧洲肿肋龙类群(Dactylosaurus,Anarosaurus,Serpianosaurus和Neusticosaurus)相比,这一单系类群与幻龙类有更近的亲缘关系。Dianmeisaurus gracilis is restudied on the basis of a new specimen. It provides some new information, especially that on the skull roof, to the species. The most striking of those new characters include the snout （preorbital region） shorter than the orbit, the interorbital septum extremely narrow, the frontal with a sharp process at both ends, and the posterior margin of the skull roof deeply V-shaped. A phylogenetic analysis with new information confirms that Dianmeisaurus is the sister group of Diandongosaurus and that these two genera, together with those Chinese taxa （Majiashanosaurus, Dianopachysaurus, Keichousaurus, and Dawazisaurus）, form a monophyletic clade which is more closely related to the Nothosauroidea than to a clade formed by the European pachypleurosaurs.

关 键 词：云南罗平 中三叠世 安尼期 始鳍龙类 纤细滇美龙 

分 类 号：Q915.864[天文地球—古生物学与地层学]