四川资中中侏罗统虚骨龙足迹化石研究

Study of dinosaur footprints(Coelurosauria) in Zizhong,Sichuan,China

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)。

This paper describes a new kind of dinosaur footprint,Chuanchengpus shenglingshanensis ichnosp.nov.,from the lower member of Middle Jurassic Shaximiao Formation in Nianpanshan Village,Jinlijing Town,Zizhong County,Sichuan Province,China.The dinosaur trackway includes 12 footprints,belonging to Chuanchengpus ichnogen Young et Young,1987.The characteristics of Chuanchengpus shenglingshanensis ichnosp.nov.are described as follows.It is a small individual Coelurosauria.The footprints of the forelimb are lost,but the tail-traces exist.The footprint is 7.5 cm long and 8.7 cm wide.It is a bipedal and tridactyl dinosaur.It walks in digitigrade way.Digit Ⅱ and Digit Ⅳ are short and oval,while Digit Ⅲ is relatively long and thick,in shape of long oval.The divaricate angle of digits is Ⅱ29°Ⅲ27°Ⅳ.The ratio of footprint length to footprint stride is 1∶6.6.The trackway is nearly straight and pace angulation is thus nearly 149°.The taxonomic position of Chuanchengpus ichnogen is revised in this paper,and Chuanchengpus ichnogen is considered to be assigned to Infraorder Coelurosauria,Ichonofamily Anchisauripodidae.