cover the shells of most turtles, the shell of the leatherback is 

 covered with a continuous layer of thin, black, often white- 

 spotted skin, overlying a layer of many thousands of irregularly 

 shaped mosaic bones that together form a continuous layer on the 

 carapace. The carapace is raised into a series of longitudinal, 

 slightly wavy or even tubercular ridges, seven in number, beneath 

 which the mosaic bones are significantly enlarged. In the 

 plastron, the mosaic bones are reduced to isolated elements 

 located along the plastral ridges. Below the mosaic bones is a 

 layer of yellowish, oily, tough but non-fibrous tissue that may 

 be 4 cm or more in thickness. 



The leatherback has many other distinctive morphological 

 features. Unlike all other turtles, there are no claws, and the 

 skin only bears scales in hatchling and very young specimens. 

 The forelimbs are exceedingly long, with a span that may exceed 2 

 m. The skeleton is very reduced, or rather is comparable to that 

 of the embryos of other turtles, the bones of the skull not 

 fusing even with maturity, and the ribs and the bones of the 

 plastron remaining splint-like and narrow throughout life. Many 

 of the bones present in the shells of other turtle species, 

 including the neurals, pleurals, peripherals, and entoplastron, 

 are absent in the leatherback; only the nuchal bone could be said 

 to be well-developed. 



Distribution ; (1) Foraging areas. The leatherback is 

 sometimes seen in coastal waters, occasionally even in small 

 groups, but it appears to be essentially a pelagic form, diving 

 in deep ocean waters to extraordinary depths, sometimes in excess 

 of 475 m. The integument of the leatherback is very delicate, 

 and the species apparently needs to avoid contact with abrasive 

 bottom substrates. The species is rather frequently encountered 

 outside the tropics, and even in latitudes approaching polar 

 waters. Leatherbacks are often reported from the waters of New 

 England and the Maritime Provinces of Canada, for example, and it 

 is possible they even reach as far north as Baffin Island. In 

 the southern hemisphere, records exist from Tasmania, the 

 southern tip of New Zealand, and so on. 



(2) Nesting areas. The leatherback nests almost entirely 

 within the tropics, extra-tropical nesting records being 

 essentially confined to low-density nesting in Florida and in 

 South Africa. Nesting is most frequently colonial, and the 

 largest colonies utilize mainland rather than insular beaches. 

 In the western Caribbean, nesting is abundant from northern Costa 

 Rica to western Caribbean Colombia, and in eastern French Guiana 

 and western Surinam. Some nesting also occurs in the central 

 part of the Brazilian coast, and important colonies are found in 

 northwestern Guyana and in Trinidad. In the Antilles, most 

 nesting occurs in the Dominican Republic and on islands close to 

 Puerto Rico, including Culebra and St. Croix (U.S. Virgin 



18 



