山西寿阳二叠系上部的锯齿龙类和二齿兽类化石

Pareiasaur and dicynodont fossils from upper Permian of Shouyang, Shanxi, China

中国二叠纪四足类的研究由来已久,在新疆和内蒙古大青山发现了大量二齿兽类(Dicynodontia)化石,而在华北地层区则以锯齿龙类(Pareiasauria)化石为主,还没有发现二齿兽类。近年来,在山西寿阳二叠系中发现了产自上石盒子组中的锯齿龙类和产自孙家沟组中的二齿兽类化石。根据髂骨的形态特征,相较于二叠石千峰龙(Shihtienfenia permica),新的锯齿龙类化石与多齿河南龙(Honania complicidentata)更相似。这表明济源动物群(河南龙组合带)可能在山西的上石盒子组中也有分布。根据头骨的特征,新二齿兽类化石属于隐齿兽目(Cryptodontia),可能是其中的某个支系在中国的第一个代表。

Chinese Permian tetrapods have been studied for decades.Many dicynodont fossils were reported from Xinjiang and Nei Mongol,only several pareiasaur species were reported in Shanxi(North China),where no dicynodonts have been reported.In this paper,a pareiasaur specimen and a dicynodont specimen are reported from the Shangshihezi Formation and the Sunjiagou Formation of Shouyang,Shanxi respectively.The pareiasaur specimen is more similar to Honania than Shihtienfenia based on iliac morphology.This suggests that the element of the Jiyuan Fauna(Honania Assemblage Zone)also occurs in the Shangshihezi Formation of Shanxi.The dicynodont fossil,an incomplete skull,is referred to Cryptodontia,and is probably the first representative of a new subclade within Cryptodontia in China.