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.
2.
The top of the stage ( also the top base of the Silesian and the base of the Permian system ) is at the first appearance of " Streptognathodus isolatus " within the " Streptognathus " wabaunsensis " " chronocline.
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