贵州紫云四大寨地区晒瓦群的中二叠世牙形刺

Middle Permian Conodonts from the Shaiwa Group in Sidazhai Area,Ziyun County,Guizhou

本文研究了贵州紫云四大寨地区的晒瓦群中部的牙形刺计有8属、3种、1比较种和6未定种(形态属种)。根据牙形刺组合的面貌特征和Sweetognathus类群的系统演化关系分析,该牙形刺组合的时代为中二叠世晚期(茅口期),同时提出该牙形刺组合所在的晒瓦群中部应当归于中二叠统上部,表明该区的晒瓦群并不仅仅代表了晚二叠世的沉积。

This paper deals with the conodonts from the Shaiwa Group （the 3rd Member） in Sidazhai area, Ziyun County, Guizhou Province, South China, comprising 8 genera, 3 species, 1 conformis species and 6 indeterminate species. Based on the components of the conodont assemblage and the phylogenetic analysis of the. Sweetognathus group, the conodont assemblage is of an age of Middle Permian （Maokouan）, and the conodont-bearing strata are certainly assigned to upper Middle Permian. It implicates that the Shaiwa Group not only includes Late Permian sediments, but also late Middle Permian deposits.