过去二十年在中国有关长羽毛兽脚类恐龙的发现，使我们对鸟类演化及飞行起源的认识发生了巨大改变，其中包括这样一个观点的提出：著名的始祖鸟化石与现代鸟类的祖先也可能还有一些距离。现在，随着另一只像鸟类的恐龙在中国辽宁省“髫髻山组”（中-晚“侏罗纪”）的发现，始祖鸟又回到了其应有的位置。新的系统发生分析恢复了始祖鸟作为一种早期分化的“鸟翼类”的地位，也重新将“伤齿龙”确定为“鸟翼类”的姐妹类群。
这些结果与中-晚“侏罗纪”鸟类在亚洲的早期分化以及鸟类靠拍打前肢来飞行的行为的单一起源观点是一致的。（生物谷Bioon.com）
生物谷推荐英文摘要:
Nature doi:10.1038/nature12168
A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds
Pascal Godefroit,Andrea Cau,Hu Dong-Yu, Francois Escuillié,Wu Wenhao & Gareth Dyke
The recent discovery of small paravian theropod dinosaurs with well-preserved feathers in the Middle–Late Jurassic Tiaojishan Formation of Liaoning Province (northeastern China) has challenged the pivotal position of Archaeopteryx, regarded from its discovery to be the most basal bird. Removing Archaeopteryx from the base of Avialae to nest within Deinonychosauria implies that typical bird flight, powered by the forelimbs only, either evolved at least twice, or was subsequently lost or modified in some deinonychosaurians. Here we describe the complete skeleton of a new paravian from the Tiaojishan Formation of Liaoning Province, China. Including this new taxon in a comprehensive phylogenetic analysis for basal Paraves does the following: (1) it recovers it as the basal-most avialan; (2) it confirms the avialan status of Archaeopteryx; (3) it places Troodontidae as the sister-group to Avialae; (4) it supports a single origin of powered flight within Paraves; and (5) it implies that the early diversification of Paraves and Avialae took place in the Middle–Late Jurassic period.
