Leatherback sea turtle and large size, leatherbacks are able to maintain high temperature differentials compared to the surrounding water. Adult leatherbacks have been found with core body temperatures that were above the water in which they were swimming. Leatherback turtles are one of the deepest-diving marine animals. Individuals have been recorded diving to depths as great as . Typical dive durations are between 3 and 8 minutes, with dives of 30–70 minutes occurring infrequently. They are also the fastest-moving reptiles. The 1992 edition of the "Guinness Book of World Records" lists the leatherback turtle moving at in the water. More typically, they swim
History of manifolds and varieties spaces with a differentiable or topological structure, while "variety" refers to spaces with an algebraic structure, as in algebraic varieties. In Romance languages, manifold is translated as "variety" – such spaces with a differentiable structure are literally translated as "analytic varieties", while spaces with an algebraic structure are called "algebraic varieties". Thus for example, the french word "" means topological manifold. In the same vein, the Japanese word "" (tayōtai) also encompasses both manifold and variety. ("" (tayō) means various.) Ancestral to the modern concept of a manifold were several important results of 18th and 19th century mathematics. The oldest