MIDDLE CAMBRIAN CONODONTS FROM THE QILIAN MOUNTAINS

There occur abundant conodonts in the Middle Cambrian Maojiagou Group in Datong county, Qinghai province.They include 7 genera and 8 species.The fauna is characterized by predominance of the protoconodonts Jiangshanodus aff. triangulus, Gapparodus bisuleatus and Phakelodus tenuis, only a few individuals of the paraconodonts Westergaardodina sp. and Prooneotodus sp. being present. In comparison with North China and South China,the proportion of paraconodonts in this assemblage decreases notably and Laiwugnathus and Furnishina are lacking.