Shell is variable, usually thick, square to triangular, somewhat compressed (creeks and small rivers) to inflated (large rivers); a broad sulcus (smooth depression) extends from umbo to ventral margin. Umbo moderately to highly elevated above hinge line. Epidermis yellowish-brown with faint green rays in juveniles, becomes dark brown with age. Inside shell beak cavity deep; pseudocardinal teeth rough and well-developed; lateral teeth serrate and straight to slightly curved; nacre (lining) white, often tinged with salmon.
Similar species: Wabash pigtoes are easily confused with round pigtoes, which generally lack a sulcus and have a rounded appearance.