Conodont biostratigraphy of the Honghuayuan Formation (late Early Ordovician) in Guizhou, South China.
Three conodont biozones are defined herein within the Early Ordovician Honghuayuan Formation based on the studies of conodont fauna from the type Section and other two sections in Guizhou. All three zones can be well correlated within the Yangtze Platform. Internationally, the Prioniodus honghuayuanensis Zone can correlate with the elegans Zone, and the Serratognathus diversus and Trangulodus bifidus zones can correlate with the proteus Zone of the Balto-Scandian conodont succession. Although with high percentage of endemic forms particularly in the lower and middle part, the fauna suggests a minimum age of the latest elegans Zone for the top of the Honghuayuan Formation and a maximum age of the latest Tremadocian (early proteus Zone) for the base of the Formation at its type locality near Honghuayuan Village of Tongzi County.