Differs from P. SOLARE in lacking four large horns with bases that touch at the back of the head. Differs from P. CORONATUM in having one (vs. 2-3) rows of enlarged scales on each side of the throat. Differs from P. PLATYRHINOS in having a double row rather than a single row of pointed fringe scales on each side of the body. Other horned lizards have either much smaller horns or a dark middorsal stripe rather than a pale one. See Stebbins (1985).