Leatherback sea turtle

The leatherback sea turtle is the sole suriving species (Dermochelys coriacea) from the taxonomic Family Dermochelyidae, and the largest living reptile in the world. Mature males and females can be as long as six and a half feet (2 m) and weigh almost 2000 lbs. (900 kg).. The largest recorded individual weighed a massive 916kg. It is an extremely long-lived organism--the average life expectancy of leatherback sea turtle is more than 150 years. This turtle earned its common name because its shell is covered with a thin layer of leathery skin. One of the most visible appearance is 7 narrow ridges. The turtle's coloration is dark with white and pink spots. Most are distributed throughout the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean, which are subtropical or tropical zones. 

Anatomy
All other marine turtles have a hard carapace, but the leatherback sea turtle has a slightly flexible carapace. There is no sharp angle between the carapace and the under-belly, and it makes a leatherback seem a barrel shaped organism. Its head is round and not able to hide into its theca. The front flippers of a leatherback are longer than any other marine turtle. The front and hind flippers look like fins, and have no claws. This absence of claws is also a key characteristic different from other marine turtles. 

Reproduction
Their mating period in the USA region is runs from about March to July. Normally, female leatherback turtles nest 5 to 7 times during nesting season. During the spawning season, females come to a sandy beach and make about a 1m deep hole. They spawn an average 50 to 160 eggs at once. Eggs are white and approximately 2in big. Usually, after 55 to 75 days from spawning, hatchlings occur during night time. Most leatherback turtles move to sea again and remigrate to their hometown beaches in 2 years intervals. Scientists believe that leatherback turtles reach reproductive maturity in 6 to 10 years. 

Ecology
Leatherback sea turtles are the most pelagic marine turtle; they live almost 4800km away from their hometowns. They can dive 1km depth to find prey. They are carnivorous, and, while their favorite food is jellyfish, they can eat anything, sometimes even attempting to get a bite off of humans. 

Extermination crisis of leatherback sea turtles
Even though leatherback sea turtles can live about 150 years, they are now registered as an endangered species. Though their meat is not used for food, their eggs have been considered a good food resource.

Related References

 * Leatherback Turtle (Dermochelys coriacea) by the National Oceanic and Atmospheric Administration
 * Leatherback Sea Turtle Fact Sheet
 * Dermochelys coriacea
 * Leatherback Sea Turtle
 * Marine Bio