North America has such a wide range of climatic regions and habitats that it has a rich and varied amphibian and reptile fauna. All together there are about 300 species of reptiles and 200 species of amphibians, ranging from the huge alligators of the southern swamps to tiny frogs no bigger than a fingernail and burrowing snakes as thin as shoelaces. It is especially rich in salamanders, and there are more species and families of salamanders here than anywhere else in the world. Where the reptiles are concerned, the warmer southern states are home to more species than the cooler northern ones, whereas the climate in the northern parts is more suitable for amphibians. The southern states, in addition to having more species, also tend to have the largest ones. The American alligator, for example, is found only in the Southeast and all the largest snakes and lizards are southern, many of them found in the deserts of the Southwest, a haven for reptiles. The Encyclopedia of North American Reptiles and Amphibians describes eighty-two species and groups of related reptiles and amphibians, all of which live in Central and North America, most in the United States. Two introductory articles also describe the basic body structure, biology, and natural history of amphibians and reptiles.

Descriptions of individual species vary from the Barton Springs salamander that occurs in just four springs in Texas to the common garter snake that lives coast to coast; from the green, leatherback, and hawksbill turtles that frequent all shores to the western diamondback rattlesnake of the driest landscapes; and from the poisonous Gila monster of southwestern deserts to the monstrous alligator snapping turtle of the Mississippi swamps. These and other examples demonstrate the vast diversity of these most intriguing groups of animals. Book jacket.