Crocodilians are the closest surviving relatives of the great dinosaurs. They have changed very little during the 150 million years that they have lived on Earth.

Alligator or crocodile? What is the difference?

Crocodile © William Warby CC BY 2.0The answer is that there is very little difference between any of the crocodilians. The easiest to identify is the gharial because it has an extremely long, thin snout. True crocodiles have lower teeth which fit into notches either side of the outer upper jaw - protruding when the jaws are closed. Alligators and caimans have broader snouts than crocodiles and the lower teeth cannot be seen when the jaw is closed - all their upper jaw teeth hang over those in the lower jaw.

Geographically speaking, true crocodiles live in Africa, Asia and the Americas; alligators are found in China and the southern United States; caimans live in South America and the gharial in southern Asia.

Read More: Adaptations for a life in water

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