A New Troodontid Dinosaur from the Lower Cretaceous Yixian Formation of Liaoning Province,China  

作　　者：SHEN Caizhi L Junchang LIU Sizhao Martin KUNDRT Stephen L.BRUSATTE GAO Hailong 

机构地区：[1]Institute of Geology,Chinese Academy of Geological Sciences [2]Dalian Natural History Museum [3]Department of Ecology,Faculty of Natural Sciences,Comenius University [4]Center for Interdisciplinary Biosciences,Faculty of Science,University of Pavol Jozef afárik [5]University of Edinburgh,School of GeoSciences [6]Institute of Geomechanics,Chinese Academy of Geological Sciences

出　　处：《Acta Geologica Sinica(English Edition)》2017年第3期763-780,共18页地质学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(41272022);the Central Public-interest Scientific Institution Basal Research Fund for the Chinese Academy of Geological Sciences(No.JB1504);China Geological Survey(grant No.DD20160201)

摘　　要：A new troodontid dinosaur, Daliansaurus liaoningensis gen. et sp. nov., is erected based on a nearly complete specimen from the Lower Cretaceous Yixian Formation of Beipiao City, Liaoning Province, China. This well preserved skeleton provides important new details of the anatomy for Liaoning troodontids, and gives new insight into their phylogenetic relationships and evolution. Daliansaurus is distinguished from other troodontids by an enlarged ungual on pedal digit IV, which is approximately the same size as the sickle-shaped second ungual, and is differentiated from other Liaoning troodontids by a number of characters of the skull, manus, pelvis, and hindlimb. A phylogenetic analysis recovers Daliansaurus within a subclade of Liaoning troodontids that also includes Sinovenator, Sinusonasus, and MeL We erect a name for this group--Sinovenatorinae--and argue that it reflects a localized radiation of small-bodied troodontids in the Early Cretaceous of eastern Asia, similar to previously recognized radiations of Liaoning dromaeosaurids and avialans. As more Liaoning theropods are discovered, it is becoming apparent that small, feathered paravians were particularly diverse during the Early Cretaceous, and future work is needed to clarify how this diversity arose, which species coexisted, and how these numerous species partitioned niches.A new troodontid dinosaur, Daliansaurus liaoningensis gen. et sp. nov., is erected based on a nearly complete specimen from the Lower Cretaceous Yixian Formation of Beipiao City, Liaoning Province, China. This well preserved skeleton provides important new details of the anatomy for Liaoning troodontids, and gives new insight into their phylogenetic relationships and evolution. Daliansaurus is distinguished from other troodontids by an enlarged ungual on pedal digit IV, which is approximately the same size as the sickle-shaped second ungual, and is differentiated from other Liaoning troodontids by a number of characters of the skull, manus, pelvis, and hindlimb. A phylogenetic analysis recovers Daliansaurus within a subclade of Liaoning troodontids that also includes Sinovenator, Sinusonasus, and MeL We erect a name for this group--Sinovenatorinae--and argue that it reflects a localized radiation of small-bodied troodontids in the Early Cretaceous of eastern Asia, similar to previously recognized radiations of Liaoning dromaeosaurids and avialans. As more Liaoning theropods are discovered, it is becoming apparent that small, feathered paravians were particularly diverse during the Early Cretaceous, and future work is needed to clarify how this diversity arose, which species coexisted, and how these numerous species partitioned niches.

关 键 词：Troodontids Daliansaurus liaoningensis Early Cretaceous Yixian Formation LIAONING 

分 类 号：Q915[天文地球—古生物学与地层学]