Mycterosaurus longiceps was named by Williston (1915). Its type specimen is FMNH UC 692, a partial skeleton (skull and few postcrania), and it is a 3D body fossil. Its type locality is Mitchell Creek, 29 (Waggoner Ranch Formation), which is in an Artinskian/Kungurian terrestrial limestone/shale in the Waggoner Ranch Formation of Texas. It is the type species of Mycterosaurus.