The question of which reptile is larger, the crocodile or the alligator, often leads to confusion due to their similar appearances. These powerful reptiles, both members of the order Crocodilia, share many characteristics but also possess distinct differences in size, physical features, and habitat.
Comparing Their Stature
When considering overall size, crocodiles generally surpass alligators. The saltwater crocodile (Crocodylus porosus) holds the record as the largest living reptile, with males sometimes reaching lengths of up to 7 meters (23 feet) and weighing over 1,000 kilograms (2,200 pounds). Average adult males range from 3.5 to 5 meters (11 feet 6 inches to 16 feet 5 inches) in length, weighing between 200 to 1,100 kilograms (440 to 2,430 pounds). The largest confirmed saltwater crocodile, named Lolong, measured 6.17 meters (20 feet 3 inches) and weighed approximately 1,075 kilograms (2,370 pounds).
The American alligator (Alligator mississippiensis) is the largest species within the Alligatoridae family. Adult male American alligators measure between 3.4 to 4.5 meters (11.2 to 14.8 feet) in length and can weigh up to 500 kilograms (1,100 pounds). The largest American alligator on record was reported to be 5.84 meters (19 feet 2 inches) long, with another weighing 473 kilograms (1,043 pounds).
Distinguishing Features
Beyond their size, several physical characteristics help differentiate crocodiles from alligators. A primary distinction lies in the shape of their snouts. Alligators have a broad, rounded, U-shaped snout. Crocodiles, on the other hand, possess a more pointed, V-shaped snout.
Another key difference is visible when their mouths are closed. With an alligator, the wider upper jaw completely overlaps the lower jaw, so the teeth of the lower jaw fit into sockets in the upper jaw and are not visible. In contrast, crocodiles have upper and lower jaws that are nearly the same width, causing some of their lower teeth, particularly the fourth tooth on each side, to protrude and be visible even when their mouth is shut, giving them a “toothy grin.” While both have bony plates called scutes, alligators have scutes primarily on their heads, whereas crocodiles have them on their body scales as well.
Where They Thrive
Crocodiles and alligators also exhibit distinct geographical distributions and habitat preferences. Crocodiles are found in tropical and subtropical regions across the globe, including Africa, Asia, Australia, and the Americas. Many crocodile species, such as the saltwater crocodile and American crocodile, can inhabit brackish water and even venture into saltwater environments due to specialized glands on their tongues that excrete excess salt. They are often found in coastal areas, estuaries, and river deltas.
Alligators have a more restricted range, primarily found in freshwater habitats within the southeastern United States and a single species in eastern China. American alligators prefer swamps, marshes, lakes, and slow-moving rivers. While they can tolerate brackish water for short periods, they are less tolerant of high salinity than crocodiles because their salt glands do not function in the same way. Florida is the only place where both alligators and American crocodiles can be found coexisting, though they typically inhabit different water types within the state.