泰国半岛侏罗纪叶肢介再研究

产于泰国半岛班关坤村附近的叶肢介化石原鉴定为 Pseudograpta cf.yuzhongensis Chen,P.jialingensisDuan,P.siamensis Duan,P.sp.,Paleoleptestheria chinensis Chen和 Palaeolmnadia?sp.等 5个属种或未定种 ,认为其时代为中侏罗世晚期。现经重新研究 ,发现这些叶肢介化石生长带上的网孔状装饰网壁相对较粗 ,网孔较深 ,孔径比 Euestheria ziliujingensis叶肢介群的分子要稍大一些 ,但远比 Pseudograpta或 N estoria叶肢介群的要小 ,基本上可以归入 Paleoleptestheria?chinensis叶肢介群 ,其生物地理区系属于古地中海水系 ,与中国西南湖群中侏罗世晚期的叶肢介动物群关系最为密切 ,其生存时代与北方地理区系的 Pseudograpta叶肢介动物群大致平行

Restudy on the Jurassic Conchostracans of Peninsular Thailand

The Jurassic conchostracans collected from Peninsular Thailand were reported as Pseudograpta cf. yuzhongensis Chen, P. jialingensis Duan, P. siamensis Duan, P. sp., Paleoleptestheria chinensis Chen and Palaeolmnadia? sp., and regard to be the late Middle Jurassic in age(Chonglarimani et al ., 1990). A restudying by the present authors shows that these fossils could be basically to the Paleoleptestheria? chinensis fauna based on the sculptures of growth bands which are ornamented with cavernous reticulations. They are much smaller than these reticulate sculpture of growth bands of Pseudograpta or Nestoria , but a little larger and deeper than the small reticulations of Euestheria or Triglypta . Palaeobiogeographically, the Paleoleptestheria? chinensis fauna distributed in the Tethys hydrographic net including Peninsular Thailand, Sichuan and Guizhou of China during the late Middle Jurassic and in the meanwhile Pseudograpta fauna lived in north and northeast China.