Abstract

A new conchostracan species Pemphilimnadiopsis cheni sp. nov. is found in the upper section of the Pennsylvanian Benxi Formation in Kaiping, Tangshan City, Hebei Province, China and is closely related to the type species of the genus, P. ortoni. This finding is the fifth record of the Carboniferous conchostracans in China. Its finding gives evidence that the Benxi Formation in Kaiping, Tangshan City can be restricted into middle-late Moscovian to early Kasimovian and the present conchostracan layers more likely correspond to the early Kasimovian. Moreover, the first described Palaeozoic insects come from the same layers in the Kaiping Basin. This study indicates the age of these fossil insects would be close to the boundary of Moscovian and Kasimovian and more likely the early Kasimovian.