This question, “What is the difference between a crocodile and an alligator?” is among the most frequently asked. First, it’s important to realise that the term “crocodilians” include not just “genuine” crocodiles, but also alligators, caimans, and members of the Family Gavialidae (gharial, Tomistoma).
However, when we talk about crocodiles, we’re talking about genuine crocodiles.
Characteristics of the jaws and skull are particularly useful in separating the three families of crocodilians. All crocodiles have the same basic skeleton in their skulls and jaws, and they all serve the same purpose.
It’s true that different bones contribute to different structures in varying degrees, though.
Lucky for us, there are external features of the skull that can be used to tell apart people from the three Families.
Comparing Alligator vs. Crocodile vs. Caiman vs. Gharial
Crocodiles, in contrast to alligators, caimans, and gharials, have the potential to attain far greater sizes. Further, they exhibit morphological differences, such as in the profile of their muzzles.
Alligators
The wide, “shovel-shaped” muzzles of most allligatorids are a distinguishing feature of this group.
Because of the upper jaw’s extreme width, many lower teeth find comfortable homes in the corresponding sockets around the outer border of the upper jaw when the jaws are closed.
The lower jaw’s fourth premolar is disproportionately huge in all crocodilians. When the jaws of an alligator or caiman are closed, the tip of this tooth is tucked into a socket in the upper jaw.
As of now, seven different alligatorid species exist across four different families (Alligator, Caiman, Melanosuchus, Paleosuchus). “alligators” refers to the American Alligator (Alligator mississippiensis).
“True” Crocodiles
As opposed to alligators and caimans, “genuine” crocodiles have narrower upper jaws. Also, the snout is narrowed or notched very severely.
Unlike alligators and caimans, “genuine” crocodiles have an enlarged fourth tooth on the lower jaw that sits in that notch, the tip of which is always visible when the jaws are closed.
An important distinction between “real” crocodiles and other reptiles like alligators and caimans is their lack of this trait.
True crocodiles (Crocodylus, Osteolaemus, and Mecistops) number in at 14 different species.
Gharials
Extremely long snouts are characteristic of the Gharial (Gavialis gangeticus) and Tomistoma (Tomistoma schlegelii).
This lengthening has been accomplished less by whole head elongation and more by cranial (back) skull compression.
As a result, a 3 m long Gharial has a somewhat similar head length to a 3 m long Saltwater Crocodile; the difference being that the Gharial’s head is much more heavily weighted toward the snout.
Alligators vs. Crocodiles vs. Gharial: Size
On average, saltwater crocodiles are three feet longer than alligators, making them the largest and most powerful members of the Crocodylia family.
The largest reptiles are crocodiles, which may reach lengths of 20 feet and weights of 2,370 pounds.
Alligators can reach a maximum length of 13 feet and a weight of 790 pounds, with the heaviest specimens ever documented weighing 1,380 pounds.
Some species of caiman can be fairly little, topping out at 6.6 feet and 88 pounds. The Amazon is home to the Black Caiman, which may reach a length of 14 feet and weigh up to 1,300 pounds.
In the end, the Gharial can grow to be 20 feet long and weigh a pound or more.
Conclusion
The 23 species that make up the order Crocodylia—the crocodilians—are both terrifying and fascinating.
There are 14 crocodilian and false gharial species, 8 alligator and caiman species, and 1 gharial (GUR-ee-ul) species in the family Gavialidae.