Alligators and crocodiles belong to a class of reptiles known as crocodilia, but they are different families of creatures. Though many people may think alligators and crocodiles are quite similar, they actually have a number of differences that clearly mark them as distinct species.
American Alligators have a U-shaped jaw with a broad snout. American crocodiles have a narrower snout with a V-shaped jaw. Alligators are generally blackish in color. Crocodiles are a grayish-green color. Differences can also be seen on the teeth of the two species. The teeth on the upper jaw of the alligator is exposed when its mouth is closed. Crocodiles have the fourth tooth on the bottom jaw exposed when their mouth is closed. Immature alligators are dark with yellow stripes. Immature crocodiles are light in color with dark stripes.
Both alligators and crocodiles are cold-blooded and will bask in the sun to store up heat. Both types will eat almost anything they can find. Both species also exhibit the “death roll’ behavior to kill their prey, dragging them underwater to kill them. Crocodiles are said to be more aggressive than crocodiles, but this can vary between different species within the family. In some parts of the world, crocodiles are very aggressive and often kill people that wander into their environments.
Alligators and crocodiles differ in their reproductive behaviors. For instance, female alligators build a mound of vegetation to lay their eggs. Crocodiles dig a hole in the sand to lay their eggs. The alligator mother will watch her nest closely while the eggs incubate. The crocodile will leave the nest, only returning when the eggs hatch. The males of both species are aggressive during mating season. The alligator is more vocal in attracting its mate.
“San Diego Zoo’s Animal Bytes: Alligator & Crocodile.” Welcome to the San Diego Zoo. N.p., n.d. Web. 8 Nov. 2012. http://www.sandiegozoo.org/animalbytes/t-crocodile.html
“Crocodilian Biology Database – FAQ – What’s the difference between a crocodile and an alligator.” Crocodilians: Natural History and Conservation – Crocodiles, Caimans, Alligators, Gharials. N.p., n.d. Web. 8 Nov. 2012. http://crocodilian.com/cnhc/cbd-faq-q1.htm
“Crocodilians in the US: The American Alligator and The American Crocodile- Final Draft.” Hays Cummins’ Home Page: Ecology, Marine Biology, Coral Reefs & Rainforests, Weather, Other Courses, Vita. N.p., n.d. Web. 8 Nov. 2012. http://jrscience.wcp.muohio.edu/fieldcourses09/PapersMarineEcologyArticles/CrocodiliansintheUS.TheAm.html