Identification of Ordovician conodont in Yongshan County of northeastern Yunnan Province and its significance of stratigraphic age constraint

The conodonts obtained from the Ordovician strata for the first time in Yongshan County of northeastern Yunnan province fills in the blank of conodont data in this area.These data show that the Ordovician strata are lack of Tongzi Formation and Honghuayuan Formation.The Meitan Formation belongs to the Lower Ordovician, the Shizipu Formation belongs to the Middle-Lower Ordovician, and the Pagota Formation belongs to the Middle-Upper Ordovician.The conodonts are similar to the Ordovician strata in the Yangtze area, but they also have their own characteristics, which are mainly reflected in the missing zone fossils in the Pagota Formation.The lack of zone fossils in the Pagota Formation is due to insufficient sample collection or differences in sedimentary environment, which needs further study.