Triangular, valves moderately thick, inflated; posterior ridge sharply angled, pointed posteriorly; periostracum green, yellow, reddish, or brown, usually rayed-fine broken V shaped or zigzag markings becoming distinctive rays with age. Beak sculpture inconspicuous fine double loops-usually obscure. Teeth well developed, nacre white, occasionally pink. Length to 2 1/2 inches. Similar to fawnsfoot, male snufbox and Wabash pigtoe.
Distribution and Habitat
Small to large rivers in soft and coarse substrate. Minnesota and St. Croix Drainages and Mississippi River below St. Anthony Falls. Has recently expanded its range above St. Anthony Falls. Often abundant in preferred habitat.