Alligators are crocodiles too. They are found in North America and China. There are two species: the American alligator (Alligator mississippiensis) and the Chinese alligator (A.sinensis). The alligators can be distinguished from the true crocodiles by their arrangement of teeth. In the alligator, the fourth tooth of the lower jaw is contained within the mouth and does not show externally. However, the fourth tooth of the lower jaw of true crocodiles fits into a notch on the side of the upper jaw and is visible when the mouth is closed. True crocodiles as mentioned earlier are placed in the family Crocodylidae. The freshwater and the estuarine crocodiles are found in India. The gharial or -longsnouted crocodile in the family Gavialydae is also found in India.