An alligator's snout is longer, wider, and more U-shaped than a crocodile's. crocodile's upper jaw line and teeth are almost the same width so the teeth are shown all in the jaw line. They also have much bigger nostrils. An alligator has a wider upper jaw, so when its mouth is closed the teeth in the lower jaw fit into sockets of the upper jaw. Alligators, have a darker coat than the crocodile. Another way of telling the difference between an alligator and a crocodile is to look at their teeth. An alligator's teeth are more "dull" than an crocodile's, where as an alligator's teeth are much more blunt than a crocodile's, which are normally much sharper.