New Study of Anshunsaurus huangnihensis Cheng, 2007 (Reptilia: Thalattosauria): Revealing its Transitional Position in Askeptosauridae |
| |
| Authors: | CHENG Long CHEN Xiaohong ZHANG Baomin CAI Yongjian |
| |
| Institution: | 1. Key laboratory of Biogeology and Environmental Geology of the Ministry of Education, China University of Geoscineces, Wuhan 430074, China;2. Wuhan Institute of Geology and Mineral Resources, Wuhan 430223, China;3. Wuhan Institute of Earthquake Engineering, Wuhan 430071, China |
| |
| Abstract: | The skull of Anshunsaurus huangnihensis Cheng, 2007, especially the skull roof, is described in detail in this paper. Compared to other genera and species of Askeptosauroidea, Anshunsaurus huangnihensis has some important transitional characters from Askeptosaurus italicus to Anshunsaurus huangguoshuensis: the rostral length related to the skull length between Askeptosaurus italicus and Anshunsaurus huangguoshuensis; the postfrontal existing but distinctly reduced; the posterolateral process relatedly short and overlapping the parietal. The phylogenetic analysis weakly supports the evolutional progress from Anshunsaurus huangnihensis to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the node among the Askeptosauridae ingroup. The evolutional direction of Askeptosauridae should be from Askeptosaurus italicus to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the evolutional progress is Askeptosaurus italicus – Anshunsaurus huangnihensis – Anshunsaurus huangguoshuensis. In biogeography provinces, the Askeptosauroidea taxa from south China have a close relationship with those from western Tethys; however, Xinpusaurus from the Late Triassic is more related to those from the eastern Pacific. |
| |
| Keywords: | Thalattosaur Anshunsaurus Triassic phylogeny |
|
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
|
