Xiuchun Jing, Hongrui Zhou, Xunlian Wang
Paleontological Research 21 (2), 183-194, (1 April 2017) https://doi.org/10.2517/2016PR021
KEYWORDS: biostratigraphy, Conodonts, Gongwusu Formation, North China, Upper Ordovician
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 these together with the occurrence of Protopanderodus species, Drepanoistodus sp. and Ansella sp. characterize the Periodon Biofacies, typical of a deeper water (upper slope) setting. Because of its slope habitat, the Gongwusu fauna differs from the contemporaneous faunas reported from the interior North China Platform, but shows a similarity to the coeval faunas in Baltoscandia, South China and Argentina.