A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin  

作　　者：XU Xing ZHAO Qi NORELL Mark SULLIVAN Corwin HONE David ERICKSON Gregory WANG XiaoLin HAN FengLu GUO Yu 

机构地区：[1]Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China [2]American Museum of Natural History, Central Park West at 79th Street, NY 10024, USA [3]Department of Biological Science, Florida State University, Tallahassee, Florida 32306-1100, USA [4]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Science Bulletin》2009年第3期430-435,共6页

基　　金：Supported by Hundred Talents Project of the Chinese Academy of Sciences, National Natural Science Foundation of China (Grant Nos. 40125006, 40472018);Na-tional Basic Research Program of China (Grant No. 2006CB806400)

摘　　要：Recent fossil discoveries have substantially reduced the morphological gap between non-avian and avian dinosaurs, yet avians including Archaeopteryx differ from non-avian theropods in their limb proportions. In particular, avians have proportionally longer and more robust forelimbs that are capable of supporting a large aerodynamic surface. Here we report on a new maniraptoran dinosaur, Anchiornis huxleyi gen. et sp. nov., based on a specimen collected from lacustrine deposits of uncertain age in western Liaoning, China. With an estimated mass of 110 grams, Anchiornis is the smallest known non-avian theropod dinosaur. It exhibits some wrist features indicative of high mobility, presaging the wing-folding mechanisms seen in more derived birds and suggesting rapid evolution of the carpus. Otherwise, Anchiornis is intermediate in general morphology between non-avian and avian dinosaurs, particularly with regard to relative forelimb length and thickness, and represents a transitional step toward the avian condition. In contrast with some recent comprehensive phylogenetic analyses, our phylogenetic analysis incorporates subtle morphological variations and recovers a conventional result supporting the monophyly of Avialae.Recent fossil discoveries have substantially reduced the morphological gap between non-avian and avian dinosaurs, yet avians including Archaeopteryx differ from non-avian theropods in their limb proportions. In particular, avians have proportionally longer and more robust forelimbs that are capable of supporting a large aerodynamic surface. Here we report on a new maniraptoran dinosaur, Anchiornis huxleyi gen. et sp. nov., based on a specimen collected from lacustrine deposits of uncertain age in western Liaoning, China. With an estimated mass of 110 grams, Anchiornis is the smallest known non-avian theropod dinosaur. It exhibits some wrist features indicative of high mobility, presaging the wing-folding mechanisms seen in more derived birds and suggesting rapid evolution of the carpus. Otherwise, Anchiornis is intermediate in general morphology between non-avian and avian dinosaurs, particularly with regard to relative forelimb length and thickness, and represents a transitional step toward the avian condition. In contrast with some recent comprehensive phylogenetic analyses, our phylogenetic analysis incorporates subtle morphological variations and recovers a conventional result supporting the monophyly of Avialae.

关 键 词：白垩纪 恐龙 古生物 关节进化 

分 类 号：Q91[天文地球—古生物学与地层学]