The upper shell (carapace) is brown or tan, with growth rings evident on younger individuals, but these are worn away on adults. The under shell (plastron) is unhinged, dull yellowish in color, with the soft parts grayish brown. The upper shell averages 9 inches to 11 inches in length with the maximum measured at 15 inches. The feet are stumpy and without webs. Their heads are large and blunt. The exposed skin of the head, neck, and legs is grayish black.