Late Bashkirian and early Moscovian conodonts from the Naqing section, Luodian, Guizhou, South China

The taxon that best matches the current concept for the base of the Moscovian Stage in its type region is the phylogenetic first occurrence of Diplognathodus ellesmerensis. An ancestral form with most of the characteristics of D. ellesmerensis occurs at Naqing. More specimens are needed to completely document the chronomorphocline, but because D. ellesmerensis is found worldwide - including that close to the base of the type Moscovian - its evolutionary first occurrence would provide an almost ideal GSSP to define the base of the international Moscovian Stage.