Crocodile and Alligator in Philadelphia Zoo

What is the difference between a crocodile and an alligator? We have this question for a long time but we never have a chance to get the answer. When we visited the Philadelphia Zoo on 22nd March 2008, the volunteer, Adrienne, gave us the answer. She explained to us in great detail by holding fake skulls of crocodile and alligator to show us their difference.

In this picture, the left one (on her right hand) is crocodile and the right one (on her left hand) is alligator. Crocodiles tend to have more pointed "V"-shaped noses while alligators have a wide "U"-shaped rounded snout like a shovel. In Crocodiles, the upper jaw and lower jaw are approximately the same width. So, teeth in the lower jaw fit along the margin of the upper jaw when the mouth shuts. Only a few front teeth are shown for crocodiles. In alligators, the upper jaw is wider than the lower jaw and completely overlaps it. Therefore, when the mouth closes, the teeth in the lower jaw are almost completely hidden. Teeth are shown all around the mouth for alligator.

If you really see a wild crocodile or an alligator, make sure that you are safe before you are trying to figure out whether it is crocodile or alligator. They can be very still. But, when either one attacks, it will be extremely fast and you will not have time to get away.