短吻贫齿龙(双孔亚纲:海龙目)的新材料及补充研究(英文)

A NEW SKELETON OF MIODENTOSAURUS BREVIS (DIAPSIDA:THALATTOSAURIA) WITH A FURTHER STUDY OF THE TAXON

记述了产自贵州关岭法郎组瓦窑段(上三叠统)短吻贫齿龙一新材料。新标本头后骨骼十分完整,使我们对该海龙的全身骨骼形态有了一个完整的认识,尤其是澄清了其肩带及前、后肢的解剖学特征。短吻贫齿龙牙齿稀少且局限于上、下颌的前端,以及末端指/趾骨(爪)扁平等性状表明,该种不是纯粹的肉食动物。依据新材料,短吻贫齿龙在局部形态上存在个体变异,并确认后肢趾趾式(2-3-4-5-5)可作为该海龙的特征之一。

A new thalattosaurian skeleton from the Upper Triassic Wayao Member of the Falang Formation, Guanling area, Guizhou Province, China can be referred to Miodentosaurus brevis. The postcranial skeleton of the specimen is well-preserved and so complete that it is worthy to be described. This new specimen provides a full knowledge of the osteology of the thalattosaurian, especially the anatomy of the pectoral girdle and both the fore- and hind-limbs. The presence of a few teeth restricted to the anterior ends of both the upper and lower jaws and dorsoventrally flattened ungual phalanges indicate that M. brevis is not a pure carnivore. With new information, some individual variations are recognized and the digital formula （ 2-3-4-5-5 ） of the pes can be identified as one of the diagnostic features for the thalattosaurian.