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记述了一件采自辽西热河群九佛堂组一新的窃蛋龙类:义县似尾羽龙(Similicaudipteryx yixianensis 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、踱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125Ma。新标本发现于义县西二虎桥地点,属于九佛堂组,距今约120Ma,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。
Describes a new species of spider and egg from the Jiufotang Formation in Rehehemiao, Western Liaoning Province: Similicaudipteryx yixianensis gen.et sp.nov. Based on its similarity to the genus Tail, And its dagger-like cauda equina, intestine, pacing and toes morphological classification of the tarantula Eupolyphaga, but some of its characteristics are also different from the Section has established the tail dragon genus , Such as the shape of cauda equina and larger individuals. The fossil has many typical characteristics of the stolen egg dragon, such as short tail, short forelimbs, etc., other than the other characteristics of stolen egg dragon also includes pubis and intestinal length ratio of 1.46, dorsal vertebral development 2 A large and deep vertebral body subdural, dorsal lateral with holes. Yixian-like tail dragon is another type of dinosaurs with true caudal bone, indicating that the tailbone, a structure previously thought to be bird-like, may have evolved independently in dinosaurs. It has some advanced features such as cauda equina, but also has some of the original features such as the healing of 5 vertebra, symphysis pubic symphysis, indicating the presence of the characteristics of mosaic in the evolutionary mosaic phenomenon. Like the tail dragon and Chi Lung, other theft Egg and other dinosaurs, toes and did not hold, there is evidence that the full grip now only appear in the birds. According to its short tail, the middle of the contraction of the phalanges and dexterous body, etc. It shows that it is a kind of suitable for fast running animals. So far, all the known cephalopods have been found in the Jianshaigou layer (section) below the Yixian Formation in the Beipiao Sihetun area, about 125Ma ago. The new specimen was found in Yuyixian West Second Tiger Bridge site, belonging to the Jiufotang Formation, dating back about 120Ma, which is by far the only one found in the Jiufotang Formation Tailosaur fossils, the study of Early Cretaceous Egg The evolution of dragons and the characteristics of the dinosaur assemblage of Jehol biota are of great significance.