The Furongian to Tremadocian conodont biostratigraphic succession of southern Kopet-Dagh Mountains, North Khorasan Province, Iran, is characterized in detail. In total conodonts of 20 genera, 38 species, and 2 subspecies have been identified. This comprehensive identification allows the establishment of 11 distinct biozones, ranging from the Westergaardodina-Prooneotodus Assemblage Zone to the Paroistodus proteus Zone, confirms the chronostratigraphic continuity of the studied sequence and permits the high resolution correlation with the global biostratigraphic standard. To analyze biodiversity and community structure, we applied several indices and multivariate cluster analysis. Overall, this study underscores the critical role of conodonts as key indicators of paleoenvironmental conditions and invaluable biostratigraphic tools. The results not only advance the reconstruction of the geological history of the region but also establish a robust foundation for future paleontological and stratigraphic research.

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