Discovery of Chondrichthyes and its Geological Significance from the Silurian of the Nanhao Area,Hainan Island

This paper described Chondrichthyes(discovery for the first time) from upper part of the third member of the Zusailing Formation of the Silurian in Nanhao area,Hainan Island.It can be correlation between second asemblage: Sinacanthus-Neosinacanthus asemblage zone and first assemblage:Hunanacanthus-Eosinacanthus in the Yangtze area,which is a part of middle Telychian age of the Llandovery epoch.They are regard as a close affinities with the corresponding period biota in the Yangtze area and Talimu basin region,based on fossils information of the Zusailing Formation including: Chondrichthyes,brochiopods,corals,trilobite and conodonts.They belong in a same Palaeobiographic region at the middle age of the Llandovery epoch.