Shell is thick, rounded to squared, moderately inflated and covered with few to many pustules (bumps) in no discernable pattern; smooth anterior third. Umbo elevated above hinge line and turned forward. Epidermis is yellowish-green to light brown in juveniles, becomes chestnut to brown with age; may have a broad green ray on the umbo. Inside shell beak cavity deep; pseudocardinal teeth well-developed and serrate; lateral teeth moderately short, heavy, serrate and straight to slightly curved; nacre (lining) white, iridescent posteriorly.
Similar species: Wartyback has knobs arranged in two weakly defined rows and the green umbo ray is not present. Purple wartyback is more compressed with a purple nacre.