Four neogondolellid conodont interval zones were recognized across the Changhsingian stage at Ganxi section, western Hubei Province, south China. They are in ascending order: the Clarkina wangi Zone, the Clarkina changxingensis changxingensis Zone, the Clarkina changxingensis yini Zone, and the Clarkina meishanensis meishanensis Zone. The present study suggests that the base of the Changhsingian can be defined by the first appearance datum (FAD) of Clarkina wangi within an evolutionary lineage from Clarkina longicuspidata to Clarkina wangi. The Wuchiapingian–Changhsingian boundary can be placed at the base of bed 104 at Ganxi section, south China because of the first occurrence of Clarkina wangi.

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