YELLOW MUD TURTLE (Kinosternon flavescens), (AGASSIZ, 1857)
Tamaulipas, Mexico. Reynosa near the Texas border
This small turtle reaches a maxium shell length of 4-5 inches (10-12.5 cm). The brown to tan oval shaped carapace has a dorsal surface that is flattened or in some instances slightly depressed. In some specimens a dark spot is present on the tips of the carapace scutes. The ninth marginal scute is higher than the eigth.The plastron is yellow to brown and has two hinges. Four rathke's glands are present on the plastron, these are the source of the foul smelling "musk". Two are located in the axillary region and the other two in the inguinal. The skin is gray to grayish with yellow to cream colored patches on the throat and jaws. In some specimens yellowish mottling is present on the face and neck. Two fleshy tubercles extend from under the chin and two more are present on the throat. The males are larger than the females and also have a tail with a cloacal opening that extends beyond the posterior margin of the carapace. Among males, the end of the tail has a horn-like tip made of keratin.