云南罗平中三叠统一海龙类新材料  

A New Material of Thalattosauria (Reptilia:Diapsida) from the Middle Triassic of Luoping,Yunnan Province

作　　者：程龙[1,2] 陈孝红 张保民 汪啸风 

机构地区：[1]武汉地质矿产研究所,湖北武汉430223 [2]中国地质大学生物地质与环境地质教育部重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2010年第4期507-511,共5页Earth Science-Journal of China University of Geosciences

基　　金：中国地质调查局"关岭生物群特征及其环境演化研究"项目(No.1212010611603)

摘　　要：海龙类前肢化石标本(YIGM SPC V 0832-2)采自于云南省罗平县新寨一带中三叠统安尼阶(Pelsonian亚阶)关岭组二段顶部.其不仅为海龙类在罗平生物群中的首次发现,而且为长颈型海龙的最早记录.该海龙类新材料虽然保存不全,但是仍具有一些独特的特征:桡骨远端两侧边缘平行;尺骨远端扩展;11个硬骨化腕骨;第三掌骨近端内侧缘发育横突;指式为2-3-4-4-4(?).虽然上述特征尚不足以建立一海龙类新属种,但是仍然反映了部分海龙类单元在向海洋适应辐射的过程保留有原始爬行类的特征.这些原始特征暗示着部分海龙类可能以营陆生生活为主.A thalattosaur forelimb specimen described here, was collected from the second member of Guanling Formation （the Middle Triassic Anisian Pelsonian） of Xinzai village, Luoping County, Yunnan Province. It is not only the first appearance of Thalattosauria from Luoping Biota, but also the oldest record of long-necked taxon （Askeptosauridea）. The incomplete skeleton of zeugopodium and autopodium is featured with the following special characters such as paralleled distolateral margins, expanded distal end of ulna, 11 ossified carpal elements, a transverse process in the proximal end of the third metacarpal and the phalangeal formula 2-3-4-4-4 （？）. These characters are not enough to define a new taxon in Thalattosauria, but they show that some thalattosaur taxa preserved some primitive characters when they were divergent to water. Furthermore, these primitive characters indicate that some thalattosaur taxa could have lived on seashore.

关 键 词：海龙目 三叠纪 地层学 云南 

分 类 号：Q911.2[天文地球—古生物学与地层学]