Conodont Biostratigraphy of the Gongwusu Formation (Upper Ordovician) in the Wuhai Area of Inner Mongolia, North China

Abstract. A well preserved Late Ordovician conodont fauna of 18 species has been recovered from seven limestone samples of the Gongwusu section in the Wuhai area of Inner Mongolia, North China. This conodont fauna is composed of Ansella sp., Belodina monitorensis, Coelocerodontus trigonius, Complexodus sp., Dapsilodus viruensis, Drepanoistodus sp., Gen. et sp. indet, Oslodus semisymmetricus, Panderodus gracilis, Periodon cf. aculeatus, Protopanderodus cf. cooperi, P. varicostatus, Protopanderodus sp., Pseudooneotodus mitratus, Scabbardella altipes, Venoistodus cf. balticus, Yaoxianognathus sp. A, and Yaoxianognathus sp., and shows a mixture of North Atlantic, North China and North American Midcontinent affinities. The presence of Belodina monitorensis, Periodon cf. aculeatus, Protopanderodus varicostatus, Scabbardella altipes and Yaoxianognathus sp. A in the fauna indicates an early Sandbian (late Sa1) age. The fauna is dominated by Periodon cf. aculeatus, Scabbardella altipes and Panderodus gracilis and ...