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首次系统研究位于四川盆地东南缘的贵州省习水县良村剖面和重庆市武隆县黄草剖面寒武-奥陶系界线附近地层的牙形石。同时,分析整理研究区已有的6个剖面的牙形石资料。据此8个剖面寒武系-奥陶系界线附近牙形石属种的分布,在研究区识别出3个牙形石带,由下至上为:Cordylodus proavus带,Monocostodus sevierensis带及Cordylodus angulatus带。寒武-奥陶系界线的国际标准化石Iapetognathus fluctivagus、我国现用的替代标准化石I.jilingensis以及我国曾用标准化石Cordylodus lindstromi在研究区的8个剖面中均未出现。通过与寒武系-奥陶系界线国际“金钉子”剖面以及前GSSP候选剖
The first systematic study of the conodont located in the Liangcun section of Xishui County, Guizhou Province, southeast margin of the Sichuan Basin and the Cambrian-Ordovician boundary of the Huangcao Section, Wulong County, Chongqing City, was the first systematic study. At the same time, we analyzed the existing 6 profiles of conodont in the study area. According to the distribution of the conodonts near Cambrian-Ordovician boundary in eight sections, three conodonts were identified in the study area, from bottom to top: Cordylodus proavus, Monocostodus sevierensis and Cordylodus angulatus . Iapetognathus fluctivagus, the standard Cambrian-Ordovician boundary line, I.jilingensis which is currently used in China, and Cordylodus lindstromi, a standard fossil in China, did not appear in all the eight sections of the study area. By contrast with the Cambrian-Ordovician boundary international “gold nail” profile and the former GSSP candidate profile