Kinosternon oaxacae

Berry and Iverson, 1980a
Oaxaca mud turtle

Kinosternon oaxacae is a large (to 17.5 cm) mud turtle with a depressed, strongly tricarinate carapace. The carapace is brownish to black, but may be darkly mottled or have dark seams. Its scutes overlap slightly. Vertebrals are variable in width and length; the 1st or 3rd through 5th are broadest, and either the 1st or 4th and 5th are shortest. The 1st touches the 2nd marginals. The cervical is small, and marginal 10 is elevated higher than the other marginals. The small plastron is notched posteriorly and double hinged, with both the anterior and posterior lobes freely movable. When closed, it does not completely cover the hindlimbs (width of hindlobe is only 57-63% of carapace width). The anterior hinge is straight, but the posterior curved, and the plastral hindlobe is slightly constricted at the hinge. The plastral formula is either abd > an > gul > hum > fem > pect (33%) or abd > an > gul > fem > hum > pect (67%). Plastron and bridge are yellow to brown with dark seams; some brown stains may be present. Axillary and inguinal scutes touch. The head is small, darkly mottled dorsally, reticulated laterally, and yellowish with a few spots ventrally. A V- or bell-shaped rostral shield is present, and the upper jaw is hooked. The jaws may be darkly streaked. Three or four pairs of barbels are on the chin. Limbs are brown to gray dorsally, cream colored ventrally. Vinculae are absent. The tail is totally brown or gray and terminates in a horny spine.
Males have concave plastra and long, thick tails. The female plastron is flat and the tail short.

Kinosternon oaxacae occurs only in the Rio Colotepec and Rio Tonameca basins on the Pacific coast of Oaxaca, Mexico.

The Oaxaca mud turtle lives in semipermanent water bodies on the coastal plain and permanent flowing waters in the uplands. It is often washed onto the coastal plain by seasonal upland flooding.

IUCN Red List Status (1996)
Lower risk: near threatened.