贵州兴义中三叠世 Nothosaurus一新种

记述了贵州兴义法郎组竹竿坡段幻龙一新种———Nothosaurusyoungisp .nov .。新种以眶后弓窄 ,上颌骨和眶后骨在轭骨之后相连 ,外翼骨形成明显的腹向凸缘 ,下颌具清晰的冠状突 ,和夹板骨前端进入下颌缝合部等特征区别于幻龙的其他种。支序分析的结果表明N .youngi的原始性仅次于N .juvenilis。新种N .youngi具有Nothosaurus中的一些原始特征 ,短的下颌缝合部 ,短的上颌齿列和窄的眶后弓 ,新种在法郎组竹杆坡段的发现支持含化石地层为中三叠世拉丁期的结论。

A NEW NOTHOSAUR FROM MIDDLE TRIASSIC OF GUIZHOU,CHINA

According to Rieppel (2000), the genus Nothosaurus contains 8 valid species ( N. mirabilis, N. cymatosauroides, N. edingerae, N. haasi, N. giganteus, N. juvenilis, N.marchicus, N. tchernovi ), which were all found in deposits ranging from the lower Anisian to the lower Carnian of the Western Tethyian faunal province (Europe, northern Africa and western Asia). More recently, a new species, N. jagisteus , was described by Rieppel (2001) based on a partial skeleton from upper Muschelkalk of southern Germany. The first representative of the genus Nothosaurus in the Eastern Tethyian faunal province is Nothosaurus sp. (Rieppel, 1998), represented by a seriously damaged skull and 5 cervical vertebrae (National Geological Museum of China Vm 1308), and previously recognized as a simosaur Shingyisaurus unexpectus by Young C C in 1965. Since the 1990s, many nothosaur specimens have been discovered from the Zhuganpo Member of the Falang Formation in Xingyi, Guizhou and in adjacent areas. The material described in the present paper was collected during the field season of 2001.