辽宁西部翼龙类化石的首次发现

DISCOVERY OF A NEW PTEROSAUR FROM WESTERN LIAONING,CHINA

辽宁北票义县组中的翼龙个体中等大小,尾短,具腹肋,前肢粗壮,桡、尺骨长于翼掌骨,后肢跖骨极细长,第Ⅴ趾退化但未消失等特征,表明它应为翼手龙亚目早期类型中一个新的属种——杨氏东方翼龙(Eosipterus yangi gen.et sp.nov.)。这是辽西翼龙类化石的首次发现,为进一步确定热河动物群的性质、地质时代,以及研究古地理古环境等提供了新资料。

A new incomplete pterosaurian skeleton. Eosipterus yangi gen. et sp. nov. , collected from western Liaoning is briefly described. It is the first occurrence of the pterosaurs from the famous Jehol Fauna in Northeast China; thus it is of great value to biostratigraphy and biogeography. According to the nature of the new pterosaur and other fossils in the same beds, this flying animal is supposed to have lived along the coast of a large freshwater lake which developed during the Late Jurassic and Early Cretaceous. The new genus and species should be assigned to the suborder Pterodactyloidea. Its main characters are given as follows: Medium-sized pterodactyloid pterosaur with a total width about 1.2m across two ends of distal wing-fingers. Tail short. Gas-tralia narrow and weak. Forelimb strong; radius and ulna 1. 3 times as long as wing-metacarpal. Wing-finger joints extensible transversely. Femur slightly straight, occupying the 2/3 length of tibia. Radius, the first wing finger as long as tibia. Metatarsal Ⅰ-Ⅳ long and narrow; phalange V of hindlimb degenerated and small.