Like HowStuffWorks on Facebook!

How to Identify Reptiles

Reptiles make up a vast section of the animal kingdom. There are more than 6500 known species of reptiles that can be divided into four groups: turtles and tortoises, lizards and snakes, crocodiles and alligators, and tuatara, a species that dates back to the dinosaurs [source: San Diego Zoo]. Differentiating between the different groups of reptiles may be easy, but distinguishing between a species can be extremely difficult. Read the tips listed below and learn about how to identify reptiles.

  • Appearance The various types of reptiles have more differences between them than similarities. However, a reptile is characterized by its scaled skin. Turtles and tortoises can be identifying by their distinctive shell. Lizards are four-legged animals with tails and either sleek or crusted scales. Their shape, size and appearance differ greatly between the species and the seasons. Snakes and lizards can often be confused, especially if they're moving quickly. However, a defining feature of a snake is that it has no legs and no eyelids [source: NHM]. It may be difficult to distinguish between alligators and crocodiles. Both are large, scaled reptiles with four legs and tails. One way to tell the difference between alligators and crocodiles is by looking at their teeth. Crocodiles have a tooth that sticks out over the upper lip when their mouths are closed, while an alligator's teeth are only visible when its mouth is open [source: San Diego Zoo].
  • Surroundings Because reptiles can be found in every type of habitat -- except for polar ice and tundra -- where you find them is a huge clue to identifying the species [source: San Diego Zoo]. Most types of turtles and tortoises can be found in water -- both fresh and saltwater -- but there is even a species that lives in the desert. Lizards are most typically found in warmer climates. Snake species differ greatly in diverse regions. They can be found on land, in water, under rocks and up in trees. Crocodiles tend to live in saltwater while alligators prefer living in freshwater [source: San Diego Zoo].