Order: Crocodillia; family: Alligatoridae

Species: Alligator mississippiensis

Thunder lizard. El Garto. American Alligator. These remarkable reptiless have changed very little during the last 150 million years. The world record in length is 19 feet, 2 inches. Some gators have been known to live to the ripe old age of 100, but the average age in the wild is 40 years.

Alligator skull. The distance between an alligator's eyes and nostrils in inches will equal its length in feet (12 inches = 12 feet).

Alligator jaws are rounded like a shovel blade (left), while crocodile jaws are more narrow with a cirucular snout. With the mouth closed, croc teeth show well in the upper and lower jaws, while with a gator the large 4th tooth on either side of the lower jaw show well.

Alligator tooth. Notice the seam running the length of the tooth.

Tooth comparison between alligators and crocodiles. Left to right: Alligator mississippiensis, Crocodylus acutus, Gavialosuchus americanus (ancient crocodile).

Alligator osteoderms (bony armour). These protective plates are like miniature solar panels, helping to convert the sun's rays to energy.

The modern crocodile and alligator have raised scutes resembling the one on the left, while the ancient croc scute is flat.

Alligator vertebrae.

Alligator coprolite. Sliced sections have revealed fossilized gar fish scales, undigested remnants of an ancient meal. If you are snorkeling or diving and spot some of this stuff on a river bottom, it's best that you determine immediately if it's recent or fossilized. If it's the former, it might be a good idea to find a new place to dive.

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