S. triporcatus is found in Belize, northeastern Guatemala, western Honduras, and Mexico.

In Mexico it is found in the Mexican states of Campeche, Chiapas, Oaxaca, Quintana Roo, Tabasco, Tamaulipas, and Veracruz.

[3] S. triporcatus is typically much larger than other species of Kinosternidae, attaining a straight carapace length of up to 36 cm (14 in), with males being significantly smaller than females.

It is typically brown, black, or green in color, with a yellow underside.

[4] Like other musk turtle species, S. triporcatus is carnivorous, eating various types of aquatic invertebrates, as well as fish and carrion.