Late
Bashkirian and early Moscovian conodonts are a
bundant and diverse at the Naqing section, South China. All conodont genera known to have numerous species in the late Bashkirian–early Moscovian are recorded here, including
Declinognathodus,
Diplognathodus,
Gondolella,
Idiognathodus,
Idiognathoides,
Mesogondolella,
Neognathodus, and
Neolochriea. At Naqing, many species of these genera provide a succession of conodont chronomorphoclines throughout the Bashkirian–Moscovian
boundary interval. They demonstrate that deposition was remarka
bly continuous through the
boundary interval, a major criterion for selecting a Glo
bal Stratotype Section and Point (GSSP). This paper descri
bes the current state of knowledge for several of these chronomorphoclines, and also provides an updated range chart of conodonts recovered from the Naqing section and their correlation with other regions.
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.