what’s the difference between alligator and crocodile
As a group, crocodilians are pretty impressive animals: Their lineage goes back 240 million years, meaning they’ve outlived the dinosaurs by a good 65 million years. Ideally suited for life in water and on land, members of the order can swim up to 20 mph (32 kph) and run up to 11 mph (17.6 kph). They’re most at home in the water and can hold their breath for up to an hour. Eyes situated atop their heads enable them to keep a lookout for prey, while their powerful tails swiftly propel them through the water.
Both alligators and crocodiles are members of the reptilian order Crocodylia. But the families they belong to, Alligatoridae and Crocodylidae respectively, differ. Often, when people use the word “crocodile” what they really mean is “crocodilian.” This term encompasses not just the common alligators and crocodiles you might already know, but also the lesser known Gavialidae family that contains the lone gavial, or gharial. All told, there are 23 species of crocodilians.
Upon closer inspection, not recommended out in the wild, you’d spot glaring differences:
They belong to the subgroup Eusuchia, which includes about 22 species divided into three families: the fish-eating gavials or gharials, which belong to the Gavialidae; today’s crocodiles or the Crocodylidae; and the Alligatoridae, or alligators. Eusuchians appeared on the scene during the late Cretaceous some 100 million or so years ago.
These scaly reptiles have been confusing and confounding humans for, well, pretty much forever. Alligators and crocodiles share plenty of similarities, but there are actually key differences between them.
Alligators and crocodiles are reptiles from the same order, Crocodilia. They’ve been around for about 200 million years—even outliving the dinosaurs! These animals are semiaquatic (able to live on both land and water) and are known to be excellent stealth hunters with keen vision and powerful jaws.
The snout shape and jawline are probably the easiest ways to distinguish alligators vs. crocodiles.
Updated February 2020
How do you tell an alligator from a crocodile? And no, dad joke enthusiasts, the answer isn’t that you see one later and the other after a while.
Many of the differences between the two center on their heads and mouths. Now, researchers from Japan have identified what they believe to be another feature that sets the reptiles apart: Alligators tend to have shorter humerus bones in their forelimbs and shorter femurs in their hind limbs than crocodiles, the team reported last week.