The average adult carapace is 10 to 13 inches long with a record length of 17-3/4 inches. The carapace is black (occasionally dark brown) with yellow to reddish orange vertebral areas. A light spot of the same color occurs at the base of each marginal. Distinct curving of the sides give a waist-line look. The plastron is yellowish brown with some dark pigment along the mid transverse seams. Some males will be very dark within the concave portion. The anterior surface of the limb is covered with large red non- or slightly overlapping scales. The color may vary from deep scarlet to orange and even yellow in some specimen.