ABSTRACT
In contrast to amphibians, many reptiles can tolerate salt water and dry conditions. Sea turtles, for example, spend their entire lives in marine habitats, while alligators and some freshwater turtles can live in estuarine or even marine waters, at least temporarily. At the other extreme, many reptiles are completely terrestrial, spending their entire lives out of the water, and even inhabiting deserts. Their ability to get along without a regular supply of drinking water far exceeds that of amphibians. A major factor in this independence from water is the reptilian egg, its hard shell and internal organization allow for incubation away from water. The live birth capability of a few (such as rattlesnakes) is similarly advantageous.
