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CENTER for BIOLOGICAL DIVERSITY Because life is good

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Reptiles are air-breathing, cold-blooded vertebrates that have scaly bodies rather than hair or feathers; most reptile species are egg-laying, though certain “squamates” — lizards, snakes and worm-lizards — give birth to live young. The earliest reptile is usually said to have been Hylonomus (a so-called "forest mouse"), which lived about 315 million years ago and resembled contemporary lizards. "Reptile" is an ambiguous category: It usually refers to lizards, snakes, turtles, alligators and crocodiles, but to be genetically consistent should also include birds, since crocodilians are more closely related to birds than to lizards, snakes or turtles. Turtles are so genetically distinct — they’re the sole surviving member of the Anapsid branch of the evolutionary tree — that many scientists recommend treating them as their own class (Chelonia) on an equal footing with birds, mammals, amphibians, fish and reptiles. Some scientists would also elevate crocodilians to the class level.

Globally, 927 species of reptiles, or 21 percent of the total 4,414 evaluated species, are endangered or
vulnerable to extinction, according to the International Union for Conservation of Nature’s Red List. Thirty-seven of those are in the United States.

Alameda whipsnake
Barbour's map turtle
Coachella Valley fringe-toed lizard
Desert tortoise
Dunes sagebrush lizard
Eastern diamondback rattlesnake
Eastern massasauga
Flat-tailed horned lizard
Florida Keys mole skink
Giant garter snake
Leatherback sea turtle
Loggerhead sea turtle
Mexican garter snake
Mojave fringe-toed lizard
Narrow-headed garter snake
San Francisco garter snake
Sonoyta mud turtle
South Florida rainbow snake
Southern and midwestern freshwater turtles
Tucson shovel-nosed snake
Virgin Islands tree boa

Photo © Paul S. Hamilton