The common belief that softshell turtles are simply a subspecies or variant of snapping turtles is inaccurate, as they represent two distinct evolutionary lineages of freshwater reptiles. While both groups are large, powerful, and share North American habitats, they belong to separate biological families. Understanding their formal classification provides the clearest distinction between these powerful aquatic species.
Taxonomical Identity and Key Differences
Softshell turtles are members of the family Trionychidae, a group characterized by their unique, flattened morphology. This classification includes species like the Spiny Softshell and the Smooth Softshell, which are widespread across North America.
Snapping turtles, conversely, belong to the separate family Chelydridae, which includes the Common Snapping Turtle (Chelydra serpentina). The separation at the family level signifies that their evolutionary paths diverged millions of years ago, resulting in fundamental differences in anatomy and behavior.
Defining Physical Features
The most immediate differences between the two families are their shell structure and overall body shape. Softshell turtles are named for their carapace, which is flat, circular, and covered in leathery skin rather than the hard, bony plates, or scutes, found on most turtles. The edges of this shell are flexible, and the flattened shape is efficient for rapid movement through the water.
Conversely, snapping turtles possess a more traditional, high-domed carapace covered in pronounced scutes, often featuring distinct ridges and a serrated rear edge. Their head and snout also present a stark contrast. The softshell turtle features an elongated, proboscis-like snout with nostrils positioned at the tip, allowing it to breathe like a snorkel while submerged in the sand or mud.
The snapping turtle has a large, robust head and a powerful, hooked jaw that forms a strong beak, adapted for ambush predation. Softshell turtles have strongly webbed feet, making them fast and agile swimmers. Snapping turtles have less webbing and possess heavy claws, indicating they are primarily bottom-walkers rather than open-water swimmers.
Differences in Temperament and Habitat
Ecological roles and defense mechanisms vary significantly between the two groups, reflecting their physical adaptations. Softshell turtles are highly aquatic and generally shy, spending most of their time submerged, often buried beneath the sandy or muddy substrate. They are known for their speed and typically try to flee from perceived threats in the water. If cornered or handled, they can be aggressive and will strike, using their long neck and sharp jaws for defense.
They prefer environments with a relatively swift current and open areas with sandbars or mudflats, where they can easily conceal themselves or bask on the shore. Their flattened shape and soft shell make them vulnerable on land, reinforcing their reluctance to leave the water.
Snapping turtles, however, are often secretive and sedentary, preferring the slow-moving, muddy bottoms of bogs, creeks, and ponds. Their defensive temperament is most pronounced when they are out of the water, such as when migrating or nesting. On land, they cannot retreat fully into their shells, making them highly defensive and leading to aggressive strikes using their powerful jaws. The common snapping turtle is a true ambush predator, patiently waiting for prey to pass by before striking.