记内蒙古阿拉善右旗晚白垩世的绘龙属(甲龙科)化石

On the Ankylosaurid Pinacosaurus from the Late Cretaceous of Alxa Right Banner,Inner Mongolia

本文记述了内蒙古西部阿拉善右旗阿拉腾敖包镇巴音塔拉一带上白垩统乌兰苏海组一件甲龙类不完整头后骨架,其愈合荐骨至少由4枚背荐椎、4枚荐椎组成,最后1对背荐肋中部和远端强烈加宽且显著向后弯曲,游离尾椎10枚,后部尾椎神经棘、前关节突与脉棘明显拉长且包裹后部尾椎椎体,应被归入甲龙亚科Ankylosaurinae的绘龙属Pinacosaurus,但种名暂未确定。阿拉善右旗巴音塔拉也成为绘龙属在内蒙古自治区继乌拉特后旗巴音满都呼、阿拉善左旗“栅栏呼都克”之后的第3个分布地点,扩展了该属化石的地理分布范围,并为阿拉善右旗巴音塔拉与乌拉特后旗巴音满都呼晚白垩世恐龙动物群的对比提供了新的古生物学依据。

An incomplete postcranial skeleton of ankylosaurs from the Late Cretaceous Wulansuhai Formation at Bayan Tal of Alaten Obo, Alxa Right Banner, western Inner Mongolia is described. Its synsacrum is composed of 4 dorsosacrals and 4 sacrals, and its last paired dorsosacral rib possesses the remarkably widened and posteriorly bent distal portion. Its caudal series include two parts: 10 free caudals, and the following handle caudals that bearing the elongated neural spines, prezygapophyses and haemal spines. This ankylosaur specimen should be assigned to indeterminate species of the genus Pinacosaurus under Subfamily Ankylosaurinae. The new material indicates that Bayan Tal of Alxa Right Banner represents the third locality yielding Pinacosaurus in Inner Mongolia Autonomous Region, after Bayan Mandahu in Urad Rear Banner and “Shanlanhuduke” in Alxa Left Banner. This finding further extends the geographical distribution of Pinacosaurus, and provides more paleontological evidences for our understanding the similarity of the Late Cretaceous dinosaur faunas between Bayan Tal of Alxa Right Banner and Bayan Mandahu of Urad Rear Banner in western Inner Mongolia.