The Leatherback Sea Turtle (Dermochelys coriacea), like all aquatic turtles, must come to land to nest. Like other sea turtles, they spend the rest of their lives in the water. The females come ashore at night in l ate spring and summer and deposit some 80 to 100 eggs, above the high-tide line, in a cavity dug with the hind flippers. Then they return at once to the sea. A turtle may nest six or more times in one season at intervals of about 10 days, but then does not nest again for two or three years.....When the eggs hatch after about 7 to 10 weeks of incubation, the baby turtles immediately move down the beach to the water. Many eggs never hatch because predators remove them from the nests and many of the newly hatched young are eaten by gulls, crabs and fish. ADults have few natural enemies other than sharks, killer whales and people.....The world's largest turtle, the Leatherback attains a shell length of 6 feet and weight of more than 1400 pounds. Leatherback turtles nest on tropical beaches throughout the world, but may travel thousands of miles north and south--as far as British Columbia on the North American west coast and to Newfoundland, Iceland, and Norway in the Atlantic Ocean.....Differing from the typical turtle shell, a bony layer covered with horny plates, the Leatherback's shell consists of tough, rubber skin over a layer of cartilaginous material. Imbedded in it is a layer of tiny, thin bones.....The dioramas of the American Museum of Natural History's Hall of Reptiles and Amphibians, with their precise depictions of geographical locations and the careful, anatomically correct mounting of the specimens, are windows onto a world of animals, their behavior, and their habitats. Moreover, since many of the environments represented have been exploited or degraded, some dioramas preserve places and animals as they no longer exist.
