|| What is the Difference
Between Alligators and Crocodiles?
28 April 1998
|Alligators and crocodiles
do look similar but there are several physical characteristics
that differentiate the two giant reptiles.
Scientists separate alligators, crocodiles, and
their cousins, caimans and gharials, according to
differences in their skulls, scales, and teeth.
The most easily observed difference between alligators
and crocodiles is the shape of the head. The crocodile's
skull and jaws are longer and narrower than the
Alligator mississippiensis, resides primarily
in the rivers and wetlands in the southeastern region
of North Carolina, but can also be found as far
north as the Albemarle Sound. Coastal North Carolina
is the northern most range for the American alligator.
In both alligators and crocodiles, the fourth tooth on
either side of the lower jaw is exceptionally long. When
an alligator closes its mouth, those long teeth slip into
sockets in the upper jaw and disappear. When a crocodile
closes its mouth, the long teeth remain visible, protruding
outside the upper jaw. In general, if you can still see
a lot of teeth even when the animal's mouth is closed, you
are looking at a crocodile. Alligators have plenty of teeth,
but fewer show until the mouth is open.
Like sharks, crocodilians never run out of teeth, for sharp
new ones grow in as old dull ones are shed throughout the
animals' lives. Numerous as they are, crocodilian teeth
serve only for grasping, not chewing. These animals gulp
their food in large chunks and rely on powerful stomach
acids to break it down.
Alligators and crocodiles both have thick, bumpy skin but
alligators tend to be darker in color. Adult alligators
are grayish black while adult crocodiles are light tan to
brown in color. Young alligators can be more colorful with
yellow or white highlights on a black body.
Another difference between crocodiles and alligators is
their choice of homes. Alligators are freshwater reptiles,
favoring the rivers, lakes, swamps, and marshes of the coast.
On the other hand, crocodiles prefer coastal, brackish,
or salt water habitats.
Crocodilians belong to the subclass Archosauria ("ruling
reptiles"), which dates back over 180 million years
and includes the vanished dinosaurs. As far as we know,
crocodilians are the only true archosaurs remaining alive
Two crocodilians are native to the U.S., the American alligator
and the American crocodile. The range of the American alligator,
found only in the Southeastern part of the country, is restrained
by cold temperatures and distribution of wetlands. The American
crocodile is even more sensitive to cold; its range is limited
to tropical areas. The American crocodile is very rare and
in the U.S. can be found only in the southern tip of Florida.
Both alligators and crocodiles are protected by state and
federal laws. The alligator is listed as a threatened species
and the crocodile as endangered under the federal Endangered