NEW LEATHER BACK TURTLE

LEATHER BACK TURTLE:                                                                                       The leatherback turtle (Dermochelys coriacea) is the largest of all living sea turtles and the fourth largest modern reptile behind three crocodilians.[2][3] It is the only living species in the genus Dermochelys. It can easily be differentiated from other modern sea turtles by its lack of a bony shell. Instead, its carapace is covered by skin and oily flesh. Dermochelys coriacea is the only extant member of the family Dermochelyidae. Instead of teeth the Leatherback turtle has points on the tomium of its upper lip. It also has backwards spines in its throat to help it swallow food. Leatherback turtles can dive to depths as great as 4,200 feet (1,280 metres).
 
Leatherback turtles follow the general sea turtle body plan of having a large, dorsoventrally flattened, round body with two pairs of very large flippers and a short tail. Like other sea turtles, the leatherback's flattened forelimbs are specially adapted for swimming in the open ocean. Claws are noticeably absent from both pair of flippers. The Leatherback's flippers are the largest in proportion to its body among the extant sea turtles. Leatherback's front flippers can grow up to 2.7 meters in large specimens, the largest flippers (even in comparison to its body) of any sea turtle. As the last surviving member of its family, the leatherback turtle has several distinguishing characteristics that differentiate it from other sea turtles. Its most notable feature is that it lacks the bony carapace of the other extant sea turtles. Instead of scutes, the leatherback's carapace is covered by its thick, leathery skin with embedded minuscule bony plates. Seven distinct ridges arise from the carapace, running from the anterior-to-posterior margin of the turtle's back. The entire turtle's dorsal surface is colored dark grey to black with a sporadic scattering of white blotches and spots. In a show of countershading, the turtle's underside is lightly colored.[5][6]

Dermochelys coriacea adults average at around one to two meters long and weigh from around 250 to 700 kilograms.[5] The largest ever found however was over three meters from head to tail and weighed 916 kilograms. That particular specimen was found on a beach on the west coast of Wales in the North Atlantic.

Physiology

The metabolic rate of the leatherback is about four times higher than one would expect for a reptile of its size; this, coupled with counter-current heat exchangers, the insulation provided by its oily flesh and large body size, allow it to maintain a body temperature as much as 18°C (32°F) above that of the surrounding water. Its large size also gives the leatherback more capacity to maintain its body temperature than smaller, more ectothermic reptiles.[2]

Leatherbacks are also the reptile world's deepest-divers. Individuals have been discovered to be able to descend deeper than 1,200 meters (3,937 feet).[2]

They are also the fastest reptiles on record. The 1992 edition of the Guinness Book of World Records has the leatherback turtle listed as having achieved the speed of 9.8 meters per second (35.28 kilometers / 21.92 miles per hour) in the water.[7][8]