Description: The alligator snapping turtle is characterized by a large, heavy head, and a long, thick shell with three dorsal ridges of large scales (osteoderms), giving it a primitive appearance reminiscent of some of the plated dinosaurs, most notably Ankylosaurus. It can be immediately distinguished from the common snapping turtle by the three distinct rows of spikes and raised plates on the carapace, whereas the common snapping turtle has a smoother carapace. M. temminckii is a solid gray, brown, black, or olive-green in color, and often covered with algae. It has radiating yellow patterns around the eyes, serving to break up the outline of the eyes to keep the turtle camouflaged. The eyes are also surrounded by a star shaped arrangement of fleshy, filamentous "eyelashes".

The species generally does not grow quite that large. Breeding maturity is attained around 18 lbs., when the straight carapace length is around 13 inches, but then the species continues to grow throughout life. Excluding exceptionally large specimens, adult alligator snapping turtles generally range in carapace length from 13.8 to 31.8 inches and weigh from 19 to 176 lbs. Males are typically larger than females. 88 adult alligator snapping turtles averaged 46.4 lbs., 92 averaged 43.5 lbs., and 249 averaged 30 lbs. Usually very old males comprise the specimens that weigh in excess of 99 lbs. per most population studies. Among extant freshwater turtles, only the little-known giant softshell turtles of the genera Chitra, Rafetus, and Pelochelys, native to Asia, reach comparable sizes.

The inside of the turtle's mouth is camouflaged, and it possesses a vermiform (worm-shaped) appendage on the tip of its tongue used to lure fish, a form of aggressive mimicry.

This turtle must be handled with extreme care and considered potentially dangerous. This species can bite through the handle of a broom and rare cases have been reported in which human fingers have been cleanly bitten off by the species. No human deaths have been reported to have been caused by the alligator snapping turtle.[

Habitat: They are generally only found in bodies of water that flow into the Gulf of Mexico and usually do not occur in isolated wetlands or ponds. A study done found that the turtles prefer places with canopy cover, overhanging trees, shrubs, dead submerged trees, and beaver dens. Females will have large home ranges.

Range: The alligator snapping turtle is found primarily in freshwaters of the southeastern United States. It is found from the Florida Panhandle west to East Texas, north to southeastern Kansas, Missouri, southeastern Iowa, western Illinois, southern Indiana, western Kentucky, Louisiana, and western Tennessee. Typically, only nesting females venture onto open land.

Found in these States: AL | AR | FL | GA | IN | KS | KY | LA | MO | MS | TN | TX

Diet: The alligator snapping turtle is an opportunistic feeder that is almost entirely carnivorous. It relies on both live food caught by itself and dead organisms which it scavenges. In general, it will eat almost anything it can catch. Fishermen have glorified the species' ability to catch fish and to deplete fish populations, whereas in fact it largely targets any abundant and easily caught prey, and rarely has any extensive deleterious effect on fish populations. Its natural diet consists primarily of fish and fish carcasses, molluscs, carrion, and amphibians, but it is also known to eat snakes, snails and other invertebrates, crawfish, insects, water birds, aquatic plants, other turtles and sometimes even small alligators. In one study conducted in Louisiana, 79.8% of the stomach contents of adult alligator snapping turtles was found to be composed of other turtles, although the resistance of shell and reptile-bone fragments to digestion may have led these fragments to remain longer in the digestive tract than other items. This species may also, on occasion, prey on aquatic rodents, including nutrias and muskrats or even snatch small to midsized other mammals, including squirrels, mice, opossums, raccoons, and armadillos when they attempt to swim or come near the water's edge.

The alligator snapping turtle seemingly most often hunts at night. It may also hunt diurnally, however. By day, it may try to attract fish and other prey by sitting quietly at the bottom of murky water and letting its jaws hang open to reveal its tongue appendage, which looks like a small, pink, worm in the back of its gray mouth, and lure the prey into striking distance. The vermiform tongue imitates the movements of a worm, luring prey to the turtle's mouth. The mouth is then closed with tremendous speed and force, completing the ambush. Although the turtle does not actively hunt its prey, it can detect chemosensory cues from prey, like the mud turtle in order to choose the location in which it is most likely to catch food. Small fish, such as minnows, are often caught in this way by younger alligator snapping turtles, whereas adults must eat a greater quantity per day and must forage more actively. Though not a regular food source for them, adult alligator snappers have even been known to kill and eat small American alligators.

Reproduction: Maturity is reached around 12 years of age. Mating takes place yearly, in early spring in the southern part of its geographic range, and in later spring in the northern part. About two months later, the female builds a nest and lays a clutch of 10 to 50 eggs. The sex of the young depends on the temperature at which the eggs are incubated. This is called temperature dependent sex determination, and it is used by all turtle species to determine sex. For the alligator snapping turtle, higher temperatures produce more males in a clutch. Nests are typically excavated at least 50 yards from the water's edge to prevent them from being flooded and drowned. Incubation takes from 100 to 140 days, and hatchlings emerge in the early fall.

Though its potential lifespan in the wild is unknown, the alligator snapping turtle is believed to be capable of living to 200 years of age, but 80 to 120 is more likely.

Status: Because of collection for the exotic pet trade, overharvesting for its meat, and habitat destruction, some states have imposed bans on collecting the alligator snapping turtle from the wild. The IUCN lists it as a threatened species, and as of June 14, 2006, it was afforded some international protection by being listed as a CITES III species (which will put limits on exportation from the United States and all international trade in this species).

The alligator snapping turtle is now endangered in several states, including Indiana, Illinois, Kentucky, and Missouri, where it is protected by state law. It is designated as "in need of conservation" in Kansas.

Subspecies: None

Taxonomy: