Notes on the discovery of Listracanthus and Petrodus (Chondrichthyes) from Upper Carboniferous of Ningxia, China

Two Chondrichthyan organ genera, Listracanthus and Petrodus, discovered in the Upper Carboniferous of Ningxia, northwestern China, are briefly described here. The two fossils, found in black shale, can correlate their Euro-American correspondents. The stratigraphical analyses have shown that Listracanthus appeared together with Petrodus in the same strata could be an index fossil for Upper Carboniferous.