Kinosternidae

The Kinosternidae are a family of mostly small turtles that includes the mud turtles and musk turtles. The family contains 25 species within four genera, but taxonomic reclassification is an ongoing process, so many sources vary on the exact numbers of species and subspecies. They inhabit slow-moving bodies of water, often with soft, muddy bottoms and abundant vegetation. Most kinosternids are small turtles, 10–15 cm (3.9–5.9 in) in carapace length. The highly domed carapace has a distinct keel down its center. The genus Staurotypus gets much larger, to 30 cm (12 in). Females are generally larger than males, but males have much longer tails. Kinosternids can be black, brown, green, or yellowish in color. Most species do not have shell markings, but some species have radiating black markings on each carapace scute. Some species have distinctive yellow striping along the sides of the head and neck.