Reptiles are a class of vertebrates made up mostly of snakes, turtles, lizards, and crocodilians. These animals are most easily recognized by their dry, scaly skin. Almost all reptiles are cold-blooded, and most lay eggs—though some, like the boa constrictor, give birth to live young. Instead of possessing gills like fish or amphibians, reptiles have lungs for breathing.
The United States is home to a diverse range of reptiles. Today these animals face threats including habitat destruction, pollution, and overexploitation. Species such as the Kemp’s ridley sea turtle and the Puerto Rican boa are currently categorized as endangered under the U.S. endangered species list.
Snakes
Limbless reptiles with long, tapered bodies
| Black Rat Snake | Louisiana Pine Snake |
| Northern Water Snake | Puerto Rican Boa |
| Rattlesnakes |
Lizards and Crocodilians
Long-bodied reptiles with limbs and tapered tails
| American Alligator | Eastern Fence Lizard |
Turtles
Terrestrial and aquatic reptiles with carapaces (top shells) and plastrons (bottom shells)
