采自塔里木西部和东北部4个主要剖面的牙形刺共有58属108种。在塔里木西部,奥陶系的牙形刺由下而上可分为Monocostodussevierensis,Chosonodinaherfurthi,Glyptoconusquadraplicatus,Paroistodusproteus(或Seratognathusdiversus),Scolopodus?tarimensis,Eoplacog nathuscrasus,E.suecicus,Pygodussera,P.anserinus,Prioniodusvariabilis,P.alobatus和Belodi naconfluens带;在塔里木东北部,奥陶系的牙形刺由下而上则可分为Cordyloduslindstromi,C.angulatus,Paroistodusproteus,P.originalis,Amorphognathusvariabilis,Eoplacognathussuecicus,Pygodussera,P.anserinus,Prioniodusalobatus,Yaoxianognathusyaoxianensis Belodin