Abstract: After reexamining the horizon producing the Dashankou Fauna and the division of Permo-Triassic strata in northern Qianlian area, China, we found the misuse of the name “Xidagou Formation”. Xidagou is held as group name for lower-middle Triassic of northern Qilian area, and cannot apply to other strata. We suggest rename former Xidagou Formation with Dashankou Fauna as Qingtoushan Formation and design the Qingtoushan section as the holostratotype; and the former Xidagou Formation applied to upper Triassic should be renamed.

摘要： 重新研究了甘肃玉门含大山口动物群的地层，讨论了北祁连区二叠和三叠系划分，指出西大沟组存在误用，建议将上三叠统的西大沟组更名，将中二叠统产大山口动物群的西大沟组更名为青头山组，并将青头山剖面指定为青头山组命名剖面。