Description: Females 5 - 10¾ inches, males 3½ - 5¾ inches. Ouachita Map Turtles have a dark olive or brown upper shell (carapace). Young Ouachita Map Turtles have a row of saw-toothed knobs down the center of the back. As they age the knobs will wear down. Adult male Ouachita Map Turtles usually keep pronounced knobs, but they may be very hard to detect in large females. The bottom shell (plastron) is light colored, and usually has no markings. The head is dark colored, with light lines extending up the neck to the back of the eye. There is a large spot behind each eye, under each eye, and on both sides of the lower jaw. The spot behind the eye may wrap around the eye and join with the spot under the eye to form a wide crescent.
Similar Species: Common Map Turtles and False Map Turtles do not have a large spot under the eye, or on the lower jaw.
Comments: Restricted to large rivers, river backwaters, and river-fed lakes.