【摘要】 通过对贵州沿河土地坳下奥陶统地层进行研究，发现较丰富的牙形石，可划分出５个牙形石生物带，自下而上为：Ｃｏｒｄｙｌｏｄｕｓａｎｇｕｌａｔｕｓ带、Ｓｃｏｌｏｐｄｕｓｑｕａｄｒａｐｌｉｃａｔｕｓ带、Ｔｒｉｐｏｄｕｓｐｒｏｅｎｓ带、Ｓｅｒｒａｔｏｇｎａｔｈｕｓｄｉｖｅｒｓｕｓ带、Ｏｅｐｉｋｏｄｕｓｅｖａｅ带。其组合面貌与黔北其它地区基本一致，系属北大西洋牙形石动物地理区。更多还原

【Abstract】 The author studied lower Ordovician conodont biostraigraph at Tudiao.Yanhe county,Guizhou province in 1989,and discovered that lower Ordovician conodont of this region was plentiful.The conodont assemblage inthis region was sinilar to those in other regions of Northern Grizhou and belongto the North Atlantic zoogeographical area.Five conodont zones were listed;that is, Cordylodus angulodus zone,Scolopodus quadraplicatus zone,Tripodusproteus zone.Serratognathus diversus zone and Oepikodus evae zone in ascending order.These zones can be correlated to the conodont assemblage zones inother parts of the world.更多还原