Conodonts of the genus Lochriea near the Visean–Serpukhovian boundary (Mississippian) at the Naqing section, Guizhou Province, South China

Abstract The First Appearance Datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa – L. ziegleri has been considered the most suitable definition and global correlation-level for a revised base of the Serpukhovian Stage. Abundant specimens of Lochriea are recorded throughout the Late Visean–early Serpukhovian interval in the Naqing section, South China. Among them, the P1 elements, with wide morphological variability, enable confirmation and refinement of main lineages within the genus. Two lineages are proposed: 1) noded Lochriea species, such as L. mononodosa – L. nodosa – L. ziegleri , L. senckenbergica and L. multinodosa , and 2) ridged Lochriea species such as L. monocostata – L. costata – L. cruciformis . The possibility for their phylogenetic relationships is evaluated in this paper.