African keeled mud turtle
This little-known species from the Congo Basin has an elongated (to 23.2 cm), oval, black carapace which is broadest at the center and has a slightly serrated posterior rim. The vertebral keel is well-developed; low on the 1st and 5th vertebrals, but higher on the 2nd through 4th, especially as a raised protuberance at the rear of the 3rd and 4th vertebrals. The keel is better developed in juveniles, but remains prominent in adults. Vertebrals are broader than long in juveniles but may become longer than broad in adults; the 1st is flared anteriorly while the 5th is expanded posteriorly. An X-ray of a paratype (MCZ 57452) shows eight neurals with the 1st and 8th reduced; the narrow 1st neural touches the nuchal but the 8th neural is widely separated from the suprapygal. The plastral anterior lobe is less than twice as long as the interabdominal seam. Instead of being indented at the abdominal-femoral seam, as in P. subniger, the posterior lobe is convex and wider at this point but behind this tapers to the rear. It is posteriorly notched. The plastral formula is: abd > fem > intergul >< hum > an > pect >< gul. The intergular is about 1.5 times as long as broad. The bridge is moderate in length and lacks an axillary scute. The plastron is yellow with a black border usually confined to the anterior lobe. The head is moderate to large with a short protruding snout and an unnotched upper jaw. Two small chin barbels are present. A long seam lies between the frontal and temporal scales. The head is brown or black with yellow vermiculations in adults and marbled with yellow in juveniles. Other skin is grayish yellow. Each foreleg has several enlarged transverse scales on its anterior surface.
Males have long, thick tails and slightly concave plastra; the female's tail is flat, as is also her plastron.
Pelusios carinatus is restricted to Gabon, Congo-Brazzaville, and the Democratic Republic of Congo.
According to Broadley (1981a), Pelusios carinatus is apparently the Congo ecological equivalent of P. sinuatus, occupying rivers, lakes, lagoons, and backwaters in dense forest.
Bour (1986) considers it most closely related to P. rhodesianus.
IUCN Red List Status (1996)