一、绪言 1984年3月,笔者在南京汤山侯家塘附近下志留统高家边组底部(或上奥陶统五峰组顶部)一层厚约20公分左右灰色硅质泥岩中首次发现 Dalmanitina yichangensis Lin,Leonaspis sinensis Chang,Platycoryphe sp.等三叶虫化石群及腕足Paromalomena polonica(Temple),Aegiromena ultima Marek et Havlicek等赫南特贝(Hirnantia)动物群。在该泥岩之下的黑色砂质页岩中,初次找到晚奥陶世末期的笔 I. INTRODUCTION In March 1984, the author first discovered Dalmanitina yichangensis Lin in the gray siliceous mudstone about 20 cm thick at the bottom of the Lower Silurian Gaojianbian Formation (or at the top of the Upper Ordovician Wufeng Formation) near the Houjiatang in Tangshan, Nanjing. , Leonaspis sinensis Chang, Platycoryphe sp. And other trilobite fossils and Parnassia fusiformis (Parr), Aegiromena ultima Marek et Havlicek and other Hernnaced (Hirnantia) fauna. In the black sandy shale beneath the mudstone, the pen of the late Ordovician was found for the first time