Largest snapping turtle

The largest snapping turtles (family Chelydridae) are the alligator snapping turtles, genus Macrochelys, named after their large head, plated shell and extremely powerful bite. Native to freshwater in the southeastern USA, they weigh up to 80 kg on average but can weigh over 100 kg, with some exceptionally large but unverified weights on record, including one specimen found in Kansas in 1937 that was famously claimed to have weighed 183 kg. In a 2009 study of alligator snapping turtles and their parasites, one turtle supposedly weighing 135 kg was noted. They generally measure up to 80 cm long, with males (wholly aquatic) being considerably larger than females (which come onto land when nesting).

In April 2014, a new study published in the scientific journal Zootaxa proposed that the alligator snapping turtle, hitherto deemed to be a single species, Macrochelys temminckii, should be split into three, based upon basic molecular differences, with the two additional species being dubbed M. apalachicolae (native to the central portion of the alligator snapping turtles' geographical range) and M. suwanniensis (native to the eastern portion), and with Macrochelys temminckii representing the western portion.