Family: Kinosternidae, Musk and Mud Turtles view all from this family

Description 3 1/2-6 3/8" (9-16.2 cm). Carapace yellow to brown, smooth, keelless, and usually flattened; scutes dark-bordered. Elevated 9th and 10th marginal scutes (lacking in young). Plastron yellow to brown, with dark pigment along seams; double-hinged, with 11 scutes. Jaw and throat white or yellow, often spotted. Male has concave plastron; long, thick spine-tipped tail; and rough scale patches on insides of hind legs. Juveniles have a dark spot at rear edge of each carapace scute.

Subspecies Some authorities recognize the following two subspecies of K. flavescens (others don't recognize any):
Yellow Mud Turtle (K. f. flavescens), yellow lower jaw, throat, and carapace; n. Nebraska to Texas, New Mexico, and se. Arizona.
Illinois Mud Turtle (K. f. spooneri), carapace brown, skin gray to black, only front of lower jaw and barbels yellow; nw. Illinois and adjacent Iowa and Missouri.

Breeding Nests in June in New Mexico. 1 clutch of 1-6 (usually 4) hard-shelled elliptical eggs. Sexual maturity is reached in 6-7 years.

Similar Species The Arizona (or Southwestern) Mud Turtle (K. arizonense), formerly considered a subspecies of Yellow Mud Turtle, has an olive carapace and the lower chin and throat yellow; it occurs from sc. Arizona into Mexico.

Habitat Prefers quiet or slow-moving bodies of freshwater with mud or sandy bottoms.

Range N. Nebraska south to Texas, e. and s. New Mexico, and se. Arizona into Mexico. Separate populations in nw. Illinois and on Illinois-Iowa border.

Discussion At dawn or twilight the Yellow Mud Turtle may be encountered foraging on land. It feeds on worms and arthropods, as well as snails and tadpoles. These turtles spend the cooler months under brush piles or leaf litter, in stump holes or muskrat dens, or under water buried in mud. Normally shy, they usually do not attempt to bite.