Pre-Archaeopteryx coelurosaurian dinosaurs and their implications for understanding avian origins

The last two decades have witnessed great advances in reconstructing the transition from non-avian theropods to avians,but views in opposition to the theropod hypothesis still exist.Here we highlight one issue that is often considered to raise problems for the theropod hypothesis of avian origins,i.e.the "temporal paradox" in the stratigraphic distribution of theropod fossils - the idea that the earliest known avian is from the Late Jurassic but most other coelurosaurian groups are poorly known in the Jurassic,implying that avians arose before their supposed ancestors.However,a number of Jurassic nonavian coelurosaurian theropods have recently been discovered,thus documenting the presence of most of the major coelurosaurian groups in the Jurassic alongside,or prior to,avians.These discoveries have greatly improved the congruence between stratigraphy and phylogeny for derived theropods and,effectively,they reject the "temporal paradox" concept.Most importantly,these discoveries provide significant new information that supports the relatively basal positions of the Tyrannosauroidea and Alvarezsauroidea among the Coeluro-sauria.Indeed,they imply a new phylogenetic hypothesis for the interrelationships of Paraves,in which Archaeopteryx,the Dromaeosauridae,and the Troodontidae form a monophyletic group while the Scansoriopterygidae,other basal birds,and probably also the Oviraptorosauria,form another clade.Mapping some of the salient features onto a temporally-calibrated theropod phy-logeny indicates that characteristics related to flight and arboreality evolved at the base of the Paraves,earlier than the Late Jurassic.

赣东北信江盆地的虚骨龙类化石

赣东北信江盆地中首次发现了虚骨龙类化石，对其产出层位、区域分布、古地理及古气候特征进行分析研究，为我国东南部白垩纪地层的区域对比提供了重要的依据。

四川资中中侏罗统虚骨龙足迹化石研究

记述了四川省资中县金李井镇碾盘山村中侏罗统沙溪庙组下段(J2s1)中的12个恐龙足迹,将其鉴定为船城足迹属(Chuanchengpus ichnogen Young et Young,1987),命名为圣灵山船城足迹(Chuanchengpus shenglingshanensis ichnosp.nov.)一新种。新种的特征为:个体小,无前足足迹,但具尾迹。足迹长7.2cm,宽8.7cm。两足行走,三趾型,趾行式。Ⅱ趾和Ⅳ趾较短,呈椭圆形。Ⅲ趾粗长,呈长椭圆形。趾间角为Ⅱ29°Ⅲ27°Ⅳ。足长与足迹复步长之比为1∶6.6。行迹呈直线,步角度为155°。对船城足迹属的分类位置进行了修订,认为应将其归属于虚骨龙次亚目(Infraorder Coelurosauria)的安琪龙足迹科(Ichonofamily Anchisauripodi-dae)。

中国辽西早白垩世义县组一新的美颌龙类（英文）

报道了美颌龙类一新属新种:季氏北票颌龙(Beipiaognathus jii gen.et sp.nov.)。它不仅具有美颌龙科的鉴定特征,如扇形的背椎神经脊和强壮的第一指第一指节,而且具有不同于其他美颌龙类的独具特征:不具有小锯齿的锥形牙齿,较长的尺骨,长而强壮的第二指第一指节,以及较短的尾部。这一发现进一步揭示了美颌龙类具有相当高的分异度,为了解美颌龙类的解剖学特征提供了重要信息。