Platyognathus hsui was named by Young (1944) [Wu & Sues (1996) created a neotype, IVPP V8266, for this species. ]. Its type specimen is CRL V.71 (neotype: IVPP V8266), a mandible, and it is a 3D body fossil. Its type locality is Huangchiatien, Lufeng, which is in a Sinemurian terrestrial horizon in the Lufeng Formation of China.