通过对研究区志留纪纱帽组牙形石、三叶虫、头足类、腹足类等生物地层的综合研究,指出该区纱帽组自下而上可分为Orthodochimioceras-Michilinoceras和Pterospathodus celloni-Apsi-dognathus tuberculatus两个生物组合,与川北陕南、黔东北石阡、四川南江、岳池等地相当层位生物群相比,前者的地质时代为特列奇期中期,后者为特列奇期中晚期。生物化石组合表明,鄂西宜都梯子口、建始三道岩志留纪纱帽组发育较完全。 Through the comprehensive study on the biostratigraphy such as conodont, trilobite, cephalopod and gastropod in the Silurianam hat group in the study area, it is pointed out that the gauze hatch group can be divided into Orthodochimioceras-Michilinoceras and Pterospathodus celloni- Apsi-dognathus tuberculatus two biological combinations, and northern Shaanxi in southern Shaanxi, Qianbei Northeast Qianjiang, Yuechi and other places comparable stratigraphic biota, the former geology time for the middle of the treachery period, the latter for the special Mid-late odd period. The biological fossil assemblage shows that the development of the Yilidu ladder mouth and the Jianshi-Shaoluodi yarn hatch group in the West Hubei Province is relatively complete.