Special Facts About Snapping Turtles

History

• Snapping turtles belong to the turtle family Chelydridae, one of the oldest groups of living turtles. Ninety-million-year-old fossils from this group have been found in North America. The snapping turtles are most closely related to the sea turtles (Carettochelyidae and Dermatemydidae), mud and musk turtles (Kinosternidae) and the softshells (Trionychidae).

Types

• Snapping turtles of the family Chelydridae consist of four species, all confined to the Western Hemisphere. Two species are found in the United States. The common snapping turtle (Chelydra serpentine) is the more commonly encountered of the two, while the alligator snapping turtle (Macrochelys temmenckii) seldom leaves the seclusion of its riverine home and is rarely seen.

Geography

• Of the four species of snapping turtle, two are found in the neo-tropics and two are found in the United States. The common snapping turtle can be found in almost all mud-bottomed, slow-water habitats east of the Rocky Mountains. The alligator snapping turtle is confined to rivers and larger streams that drain into the Gulf of Mexico--from eastern Texas north to Kansas and western Illinois southeast to Georgia and western Florida.

Identification

• Snapping turtles are all large-headed, powerfully jawed species with large bodies and well-developed shells. The tip of the upper jaw is hooked downward. The rough upper shell (carapace) is keeled, and its posterior margin is serrated. The extensive carapace is connected to a cross-shaped, reduced and unhinged lower shell (plastron) by a narrow bridge on each side. The carapace of both species may be worn smooth in older individuals and is often covered in mud or algae, which obfuscates the characters of the shell.

Size

• A snapping turtle's size is large determined by environmental factors. Turtles will grow largest where the weather is warmest and food is most readily available. Common snapping turtles typically grow between 8 to 14 inches in straight-line carapace length and weigh between 10 and 35 pounds. The largest common snapping turtle ever reported measured 19.4 inches. They are known to live up to 50 years but probably exceed this. Alligator snapping turtles typically reach 16 to 27 inches and weigh 30 to 170 pounds. The largest reported specimen measured 31.5 inches in carapace length. Alligator snapping turtles are known to have lived for 70 years and five months in captivity. Male snapping turtles grow larger than females.

Considerations

• A turtle's DNA is the prime determinate for its body structure. However, the environmental characteristics of the nest in which the young turtle develops plays the defining role in determining the turtle's gender and size at hatching. During a young turtle's development within the egg, a critical point is reached at which the sex is determined by the nest temperature. Additionally, the eggs situated near the periphery of the nest yield the largest hatchlings, due to the increased availability of moisture compared to those eggs in the center of the nest.

Warning

• Upon removing a common snapping turtle from its watery home, you will soon be reminded how it got its name. Snapping turtles will strike and lunge repeatedly in an effort to bite. Snapping turtle bites are painful, and large turtles are capable of inflicting significant damage. Care should be taken to keep a safe distance between the turtle's mouth and your body.