古脊椎动物学报2004，Vol.42Issue(2)：111-119,9.
辽宁西部早白垩世义县组一新驰龙类
A NEW DROMAEOSAUR (DINOSAURIA:THEROPODA)FROM THE EARLY CRETACEOUS YIXIAN FORMATION OF WESTRN LIAONING
摘要
Abstract
A specimen collected from the Early Cretaceous lowest part of Yixian Formation of Liaoning, northeastern China, represents a new genus and species of dromaeosaurid theropod. It comprises a fragmen tary maxilla with some teeth, a few caudals, almost complete fore limbs, and partial hind limbs and is here named Graciliraptor lujiatunensis gen. Et sp. Nov. Distinctive characteristics of the new species include a laminal structure connecting the postzygapophyses of middle caudals, middle caudals extremely long and slender, small manual ungual I, proximal end of metacarpal Ⅲ strongly expanded, proximal tibiotarsus shaft rectangular in cross section, astragalar medial condyle significantly expanded posteriorly, metatarsal Ⅱ dis tally much wider than the other metatarsals and long and slender pedal phalanx Ⅲ-1. Being the earliest def initive dromaeosaurid species known to date, G. Lujiatunensis provides new information important for under standing the early evolution of the group. On one hand, G. Lujiatunensis displays a few features similar to those of basal birds, such as caudals significantly elongated, semilunate carpal small and primarily contact ing metacarpal Ⅱ, and manual digit Ⅰ short, providing further evidence for a close relationship between the Dromaeosauridae and the Aves; on the other hand, it is similar to troodontids in some features on the cau dals. The discovery of G. Lujiatunensis also indicates a high diversity of the Dromaeosauridae in the Early Cretaceous Jehol Biota. Combined with other lines of evidence, it is inferred that the Dromaeosauridae rap idly diversified taxonomically but remained relatively stable morphologically in the early evolution of the group.关键词
辽宁西部/早白垩世/义县组/驰龙类Key words
Western Liaoning/Early Cretaceous/Yixian Formation/Dromaeosauridae分类
生物科学引用本文复制引用
徐星,汪筱林..辽宁西部早白垩世义县组一新驰龙类[J].古脊椎动物学报,2004,42(2):111-119,9.基金项目
国家自然科学基金委员会创新群体基金、国家重点基础研究发展规划项目(编号:G2000077700)和国家自然科学基金委员会杰出青年基金(编号:40125006)资助. （编号:G2000077700）
