四川三列齿类似卞氏兽(兽形类爬行动物)的头骨

似卞氏兽是兽形类三列齿类里的晚期代表.与其他同类比较,它具有吻部缩短,上颌骨被大面积覆盖和基蝶副蝶骨区宽阔平坦等特征.本文还研究了在犬齿兽类进化到三列旨类过程中在耳区的骨骼形态和静脉循环等方面的变化,也探讨了这类动物牙齿生长替换和咬合等特征。     

新疆的二迭纪三迭纪爬行动物化石

地球史上的二迭纪和三迭纪,正是低等爬行动物大量辐射和繁盛的时期,对这一时期动物群分布的研究有助于对当时古地理的探讨。二迭纪晚期至三迭纪早期,在南非有着一个很丰富的动物群,即卡鲁系的波福特层     

SKULL MORPHOLOGY OF THE TRITYLODONT GENUS BIENOTHEROIDES OF SICHUAN

Bienotheroides wanhsienensis, known as the latest, representative of the tritylodont groupis characterized by the very short snout, largely covered maxilla and wide and flat basi-parasphenoid region, as compared with the others. In this paper the evolutionary changesof the osteology and venous system of the ear region from cynodonts to tritylodonts aredescribed and the growth and replacement of the postcanine teeth and the occlusion of thisanimal are discussed.