辽西热河生物群一新的巨龙型类恐龙

初步研究了辽西地区热河生物群的一具近完整的蜥脚类恐龙骨架,其代表了一新的巨龙型类恐龙——中国辽宁巨龙(Liaoningotitan sinensis gen.et sp.nov)。其主要特征为:上颌骨腹缘下凸,上颌齿列短且位于前部;颧骨前端近平齐于眶前窗的前缘;翼骨的方骨支基部收缩;上颌齿呈叠瓦状排列;上颌齿冠窄勺形,切面呈D字形,缺失唇侧沟和小锯齿;下颌齿9枚,明显小于上颌齿,排列稀松;下颌齿冠不对称,切面呈椭圆形,舌侧的沟和嵴发育,齿冠基部向舌侧膨大;肱骨近端扩展,约为长度的54.9%;肠骨前髋臼突前端较尖。初步的支序分析显示,辽宁巨龙属于巨龙型类恐龙,是比盘足龙和梁龙更为进步的类群。

A new titanosauriformes dinosaur from Jehol Biota of western Liaoning,China

A nearly complete sauropod skeleton, collected from the Jehol Biota of western Liaoning, is described briefly as a new titanosauriformes, Liaoningotitan sinesis gen. et sp. nov. Its diagnostic characters include:ventral margin of maxilla is convex, upper tooth row is short and anteriorly positioned; anterior extension of jugal nearly reaches the level of the anterior margin of the antorbital fenestra; quadrate wing of the pterygoid constricted basally; upper teeth are imbricated, narrow spatulate crown is D-shaped in cross section, with labial grooves and denticles absent; well reduced and un-imbricated nine lower teeth; lower tooth crown is asymmetric, elliptical-like in cross section, lingual grooves and ridge present, basal crown bulbous lingually; proximal expansion of the humerus is about 54.9% the length of the humerus, ilium with a pointed preacetabular process. Preliminary result of the phylogenetic analysis shows that Liaoningotitan falls into the clade of titanosauriformes, and is more derived than Euhelopus and Brachiosaurus.