How to Tell The Difference Between A Crocodile And An Alligator

Crocodiles are usually found in saltwater habitats.

Both crocodiles and alligators are fearsome predators of the wetlands. Unless you are at a zoo with signs and educational exhibits, it can be difficult to tell the two reptiles apart. All alligator and crocodile species are a part of the Crocodilia order, but they are split into two families -- Alligatoridae and Crocodylidae. Several differences in their appearance and body structure can be used to identify the animals.

Instructions

1. 

   Alligators are native to the southern United States and eastern China.

   Identify the alligator or crocodile by location. If you see one of the reptiles in the wild, you can narrow down whether it is a crocodile or alligator based on where you are. Alligators live in the southern United States and eastern China. They tend to make their homes in slow-moving rivers and grassy swamps. The crocodile's native habitat is Africa, southeast Asia, Australia, and North, South and Central America. The animal prefers saltwater areas. The only place where the two species' habitats overlap is in south Florida.

2. Examine the shape of the jaw. Alligators have rounded, wide snouts. It appears to be U-shaped. Crocodiles have V-shaped jaws. It is longer and more pointed. Alligators have stronger jaws than crocodiles.

3. Check out the reptile's teeth. The alligator's upper jaw completely overlaps its bottom jaw so you will only see the teeth on the top when the mouth is closed. Crocodiles, however, have upper and lower jaws of the same size. You will see the teeth of both the top and bottom when a crocodile has its mouth closed. The key is to look for the fourth tooth in the lower jaw. If you can see it when the reptile has its mouth close, it is a crocodile.

4. Look at the animal's skin. The scales from a crocodile will have a dimple or small dark spot, while alligator skin does not. This is especially apparent on skin apparel such as boots and wallets. Crocodiles have integumentary sense organs all over their bodies. These small, sensory pits detect prey and pressure changes in the water. Scientists also believe they help with chemical and salinity detection. Alligators do have these sensory organs but only around the jaws.

Tips & Warnings

• Another difference that is difficult to see while observing these animals in the wild or even at a zoo is that crocodile tongues have functioning salt glands. Alligators have these glands as well, but they do not use them. These modified salivary glands make life in saltwater habitats possible for crocodiles.

• The differences in jaw, teeth and skin are a basic way to tell crocodiles and alligators apart but are not always a definitive method. Twenty-three species of crocodile exist in the world and significant variation exists in their appearance. The Indian mugger has a jaw similar to that of an alligator, but it is a crocodile.

References

• Florida Museum of Natural History Crocodilian Biology Database: What's the Difference Between a Crocodile and an Alligator?
• San Diego Zoo: Alligator & Crocodile
• Animal Planet: Ask a Croc Expert

Resources

• Florida Fish and Wildlife Conservation Commission: Differences Between Crocodiles and Alligators