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Vertebrata Palasiatica ›› 2008, Vol. 46 ›› Issue (3): 178-189.

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A NEW GENUS AND SPECIES OF CAUDIPTERID DINOSAUR FROM THE LOWER CRETACEOUS JIUFOTANG FORMATION OF WESTERN LIAONING, CHINA

HE Tao, WANG Xiao-Lin, ZHOU Zhong-He   

  • Online:2008-09-15 Published:2008-09-15

辽西下白垩统九佛堂组尾羽龙类一新属

何  涛 , 汪筱林 , 周忠和   

Abstract: A new oviraptorosaur, Similicaudipteryx yixianensis gen. et sp. nov. is described from the Jiufotang Formation (120 Ma) of the Jehol Group in western Liaoning, China, which is referred to the Caudipteridae based on a dagger-like pygostyle and the shape of the ilium that are most similar to those of Caudipteryx. It differs from other oviraptorosaurids in that the ratio of pubis to ilium length is 1.46 and the presence of two large and deep hypapophyses on dorsal vertebrae. The known caudipterids have previously been found only from the Jianshangou Member of the Yixian Formation (125 Ma) of the Sihetun area in Liaoning Province. S. yixianensis represents the first caudipterid dinosaur from the Jiufotang Formation. The new discovery provides more information for the discussion of the evolution of oviraptorids during the Early Cretaceous and adds to the dinosaur assemblage of the Jehol Biota.

摘要: 记述了一件采白辽西热河群九佛堂组一新的窃蛋龙类:义县似尾羽龙(Similicaudipteryx yixianensisi gen. et sp. nov.), 并依据其和尾羽龙属的相似特征,及其匕首状的尾综骨,肠骨、蹠骨和脚趾的形态等将其归入窃蛋龙类的尾羽龙科,但其所具有的一些特征也不同于该科已建立的尾羽龙属,如尾综骨的形态和较大的个体等。该化石具有许多典型的窃蛋龙类的特征,如短尾、较短的前肢等,有别于其他窃蛋龙类的特征还包括耻骨和肠骨的长度比为1.46,背椎上发育2个大而深的椎体下突、背椎侧部具孔等。义县似尾羽龙是又一类具有真正尾综骨的恐龙,表明尾综骨这一曾经被认为是鸟类特有的结构可能是在恐龙中独自演化的。它具有一些进步的特征如具尾综骨等,但同时也具有一些原始的特征如5个愈合的荐椎,耻骨联合长,表明在窃蛋龙类中存在着特征的镶嵌进化现象。似尾羽龙与驰龙类、其他窃蛋龙类等恐龙一样,脚趾并没有对握,已有的证据说明完全的对握目前还只是出现于鸟类中。根据其短尾、中部收缩的趾骨和灵巧的身体等都表明它是一类适于快速奔跑的动物。目前为止,已知的尾羽龙类化石均发现于北票四合屯地区的义县组下部尖山沟层(段),距今约125 Ma。新标本发现于义县西二虎桥地点,属于九佛堂组,距今约120 Ma,这也是迄今为止在九佛堂组发现的惟一一件尾羽龙类化石,对研究早白垩世窃蛋龙类的演化和热河生物群恐龙组合的特征具有重要的意义。