 The top of the stage (the base of the Permian system) is at the first appearance of the conodont "Streptognathodus isolatus" within the "Streptognathus "wabaunsensis"" chronocline.Six meters higher in the reference profile, the Fusulinida species "Sphaeroschwagerina vulgaris aktjubensis" appears.At the moment (2008), a golden spike for the Gzhelian stage is yet lacking.