Snapping turtles are large freshwater reptiles whose appearance is often described as ancient or prehistoric. They are among the largest native North American turtles, distinguished by their rugged look and predominantly aquatic lifestyle. This physical form allows them to be effective bottom-dwelling predators in the ponds, lakes, and rivers they inhabit.
The Distinctive Shell and Plastron
The shell, or carapace, is rough-textured and lacks the smooth dome found on many aquatic turtles. It often has a dark coloration, ranging from dark brown to black or olive green, and is frequently covered in algae, which aids in camouflage within murky waters. The carapace size for a common snapping turtle generally falls between 8 and 18.5 inches in length.
The lower shell, known as the plastron, is reduced in size and cross-shaped. This small plastron leaves a significant portion of the turtle’s body, including the legs and neck, exposed. Unlike many other turtles, the snapping turtle cannot fully withdraw its head and limbs into the shell for protection. They rely on their defensive snapping behavior when encountered on land.
Head, Jaws, and Long Neck
The snapping turtle possesses a disproportionately large, heavy head. The head is attached to a thick, muscular neck that is highly mobile and flexible, allowing for the rapid, snake-like strike for which the species is named. Their mouth forms a strong, hooked, beak-like structure made of bone, designed for a powerful bite.
The eyes are relatively small and positioned high on the head, enabling the turtle to remain mostly submerged while scanning its surroundings. The skin on the neck and legs is thick and often covered in characteristic bumps, or tubercles. The tail is exceptionally long and thick, often nearly the same length as the carapace, and is adorned with saw-toothed ridges along its upper edge.
Key Differences: Common vs. Alligator Snapper
The Common Snapping Turtle (Chelydra serpentina) and the Alligator Snapping Turtle (Macrochelys temminckii) have several visual distinctions. The Common Snapper has a smaller head relative to its body and a carapace that becomes smooth as the turtle ages. Its eyes are positioned more on the sides of the head.
The Alligator Snapper looks more armored and prehistoric. It has a larger head and its carapace features three pronounced longitudinal ridges, or keels. The Alligator Snapper’s eyes are oriented forward, and the species is known for a unique, fleshy, worm-like appendage on its tongue that it uses as a lure to attract fish.