  Alligators are often confused with crocodiles. The confusion is understandable, since they look pretty similar. All alligators and crocodiles belong to a taxonomic order called Crocodylia. Crocodylia is then split up into three major families; Alligatoridae (alligators), Crocodylidea (crocodiles) and Gavialidae (gharial). We're going to look at the two most well known families, the alligators and the crocodiles. The two may look very similar, but there are some surprising differences that are easy to spot.
 There are internal differences as well. Compared with crocodiles, the forelimbs of alligators have a shorter humerus bone and their hind legs have shorter femurs.  Crocodiles have salt glands on their tongues, which allows them to get rid of excess salt from their bodies. This ability allows some to live in salty marine environments. One example is Australia's saltwater crocodile, which lives in mangrove swamps and deltas.  Alligators have the same salt gland, but it isn't very effective and limits the alligator's tolerance for salt water, so alligators mostly stick to freshwater habitats such as lakes and marshes. This trait may explain the global distribution of the creatures. Crocodiles can be found across the North and South America, Africa, Asia and Australia, while alligators are mostly found only in North and South America, and China.
 Although both alligators and crocodiles can be dangerous, alligators are usually much less aggressive than crocodiles. When cleaning alligator pools in zoos, the keepers can usually walk near to them without getting a response. Crocodiles, on the other hand, almost always react aggressively. Both reptiles have tiny black specks called integumentary sense organs on their heads. These sensory organs allow them to detect pressure changes in the water caused by potential prey. The organs can be found only on the head and around the mouth of alligators, while crocodiles have them all over their bodies. |
