Crocodilians—which include alligators, crocodiles, caimans, and gharials—are some of the oldest animals on the planet, having first appeared about 230 million years ago! The only reptiles older that crocodilians are turtles, tortoises, and tuatara. And would you believe crocodilians are more closely related to birds and dinosaurs than most living reptiles?
These cold-bloodedAn animal whose body temperature changes with the temperature of the air or water around it, as a turtle or fish., thick-skinned, egg-laying animals strike fear in the hearts of many and respect in others. They are certainly misunderstood, and most face serious threats to their habitatWhere an animal or plant normally lives and grows. as well as being hunted for their skin. It's not easy being a croc!
And how can you tell a crocodile from an alligator? At first glance, they seem pretty similar. Here are a few clues: first, look at the jaw. Alligators tend to have wide, U-shaped, rounded snouts, while crocodiles usually have longer, more pointed, V-shaped snouts.
Teeth tell the truth! The fourth tooth on the lower jaw sticks up over the upper lip on crocodiles, so you can see it when their mouth is closed. In alligators, this fourth tooth is covered up.
Home, sweet home: although there are some exceptions, crocodiles most often live saltwater habitats, and alligators like to live in freshwater habitats.
Crocodilians may be fierce carnivores, but they play an important role in the ecosystemAll living things depending on one another to survive in a certain area.. So remember—crocs rock!