A New Early Cretaceous Turtle from Otog Qi, Inner Mongolia, China
1) Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037
2) The Geological Museum of China, Beijing, 100034
Abstract:Abundant fossil turtles have been known from the Early Cretaceous deposits of the Ordos region,Inner Mongolia. A new species of Sinemys, S. chabuensis sp. nov, is erected based on a nearly complete turtle carapace that was excavated from the Jingchuan Formation of Otog Qi, Ordos. This species is characterized by its very wide third vertebral scute with its width doubling its length and its length of anterior lateral margin 17 times the length of posterior lateral margin, the contact between the paired eighth pleural plates at midline, very broad first suprapygal plate, and the very developed lateral spine from the seventh peripheral plate. At least two turtle species have been reported from the Early Cretaceous Jingchuan Formation and other two taxa from the underlying Luohandong Formation from Ordos region, respectively. There appear some successions and differences of the turtles between the two formations.