The leatherback is the largest living turtle and is so distinctive that it is placed in its own separate family, Dermochelys. All other sea turtles have bony hard plates on their shells (carapace). The leatherback's carapace is slightly flexible and has a rubbery texture. No sharp angle is formed between the carapace and the under-belly (plastron) so a leatherback is somewhat barrel-shaped. Many can grow to be bigger than one too. The front flippers of a leatherback are longer than in the other marine turtles, even when you take the leatherback's size into account. They can reach 8 feet cm in adult leatherbacks. The largest leatherback on record was a male stranded on the West Coast of Wales in 1988. He weighed two thousand pounds. In 1982, it was estimated that 115,000 adult female leatherbacks existed worldwide and that roughly half of them probably were nesting in western Mexico. In recent years, however, the number of nesting leatherbacks has been in an alarming decline. This coin comes with a mint issued Certificate of Authenticity.