Caseopsis agilis was named by Olson (1962). Its type specimen is CNHM (FMNH) UR 253, a partial skeleton (patial skull and several postcrania), and it is a 3D body fossil. Its type locality is Locality KV (San Angelo Fm.), which is in a Kungurian/Roadian floodplain shale/conglomerate in the San Angelo Formation of Texas.