【摘要】 采自四川马角坝泥盆系观雾山组顶部的几个牙形石样品有Ancyrodella alata,Icruidus subterminus,Polyguathus alatus,P.asymmetricus,P.dubins,P.ovalis,P.of.Peiatus,以及P.rylus xylus等属种,大致代表了asymrnetricus下亚带,时代为弗拉斯早期。因此,观雾山组顶部已经属上泥盆统。文中简要描述了牙形石3属8种。更多还原

【Abstract】 Several conodont samples from the top of the Guanwushan Formation in Majiaoba, north-ern Sichuan yield following conodonts: Ancyrodella aluta, Icriodus sublerminus, Polygnathus alatus, P. dubis,P. asymmetricus, P. ovalis, P. of. pennatus and P. xylus xylus. This fauna represents the lower asymmet-ricus zone and implies the early Frasnian in age. Therefore, the top of the Guanwushan Formation al-ready enters the Upper Devonian. 8 species belonging to 3 genera are briefly described.更多还原