The Differences Between Alligators and Crocodiles

Did you know that alligators and crocodiles have been around for over 230 million years? Although they may look similar to the ordinary person, there are distinct differences between the two.

There are three families of crocodilians: alligatoridae, crocodylidae, and gavialidae. Across these three families, there are 23 different species that have existed for over 240 million years, making them 65 million years older than the dinosaurs.

These predatory killing machines are perfectly designed for water-life, with some crocodilians able to swim up to 20 miles per hour and run up to 11 miles per hour on land. They have well-located eyes for vision, even at night, and have sharp hearing that allows them to hear their offspring calling them from inside their eggs.

One major difference between alligators and crocodiles is the shape of their snout. Crocodiles have longer, V-shaped snouts, while alligators have shorter, U-shaped snouts. The alligator’s broad snout is designed for strength, while the crocodile’s pointed snout is more generalized for a wider variety of prey. However, there are exceptions to this rule, such as the Indian Mugger Crocodile.

Other differences include the placement of teeth, with crocodiles having teeth in both upper and lower jaws, while alligators only have teeth in their upper jaw. Alligators also have a bony plate on their lower jaw, which is absent in crocodiles.

Overall, these ancient creatures are fascinating and have evolved over millions of years to become some of the most efficient predators in the animal kingdom.

Variation #2 – Smiling Teeth

A noticeable difference between alligators and crocodiles is the visibility of their bottom jaw teeth.

When an alligator’s mouth is closed, the teeth on its lower jaw are mostly hidden because its upper jaw has small sockets where the teeth slot in.

On the other hand, a crocodile’s upper and lower jaws have roughly the same width, causing the upper teeth to interlock with the lower teeth when its mouth is closed.

As a result, the large fourth tooth on the lower jaw of a crocodile remains visible when its mouth closes because it slots into a well-defined space in the upper jaw behind the nostrils.

Moreover, if you observe closely, alligator teeth appear more rounded, while crocodile teeth are more pointed.

However, it’s better not to get too close to notice the difference!

Variation #3 – Dermal Pressure Receptors (DPRs)

The faces of crocodiles and alligators have tiny black speckles called Dermal Pressure Receptors (DPRs), which help them sense small pressure changes in water to catch their prey.

While both alligators and crocodiles have these receptors on their faces, crocodiles have them covering their entire body, while alligators do not.

Scientists suggest that these receptors on crocodile skin may expand the sensory surface over their entire body, but their exact function is still unknown.

Regardless, DPRs are an easy way to differentiate crocodile skin from alligator skin.

Variation #4 – Habitats

Alligators cannot tolerate salt like crocodiles, so they typically inhabit freshwater habitats.

In contrast, crocodiles prefer more saline habitats.

Although it is rare, large alligators sometimes venture into estuaries and coastlines.

Alligators are found in limited regions of the world, including the US, Mexico, and China, while crocodiles inhabit more parts of the world naturally.

Variation #5 – Skin Color

The skin of adult alligators is usually a darker grayish-black color, while adult crocodiles have a lighter tan/brown skin.

The difference in skin color is due to the type of habitat they live in.

Alligators tend to live in dark water, such as swamps and slow-moving rivers, while crocodiles prefer lighter-colored waters, making a lighter skin tone more suitable for camouflage.

Young alligators may have white or yellow highlights on their black bodies, but this is not a significant difference between alligators and crocodiles.

Variation #6 – Lingual Salt-Glands

In my opinion, one of the most fascinating animals is the crocodile, which has salt glands on its tongue that allow it to excrete large amounts of salt from its surroundings. Although not easily noticeable, these glands become visible when crocodiles bask in the sun with their mouths open. This unique ability means that crocodiles can tolerate more salty water than alligators, making them suited for habitats such as tidal estuaries, coast-lines, and even oceans. Alligators, on the other hand, have lost this ability and prefer freshwater habitats like swamps and lakes. The fact that crocodiles can tolerate saltwater suggests that they may have an ancestral marine history and could have migrated around the world through the seas, which explains their widespread variety across the globe.

Another interesting difference between crocodiles and alligators is their mating behavior. A recent study found that up to 70 percent of female alligators mate with the same male year after year, displaying similar behavior to some birds that mate for life. However, this behavior is not observed in crocodiles, as studies have shown that some batches of crocodile offspring can contain genes from several different males.

In summary, these unique characteristics differentiate crocodiles from alligators. If you ever come face to face with one of these creatures, this article may help you identify whether it’s a crocodile or an alligator.


1. What’s the difference between alligators and crocodiles?

While alligators and crocodiles may look similar, there are a few key differences between the two species. One major difference is their snouts – alligators have wider, U-shaped snouts while crocodiles have longer, V-shaped snouts. Additionally, alligators tend to live in freshwater habitats, while crocodiles can be found in both freshwater and saltwater environments. There are also differences in their teeth – alligators have a wider upper jaw and teeth that are more visible when their mouths are closed, while crocodiles have a more narrow upper jaw and teeth that are visible even when their mouths are closed.

2. Which species is more aggressive – alligators or crocodiles?

Both alligators and crocodiles can be aggressive if provoked or if they feel threatened. However, crocodiles are generally considered to be more aggressive and territorial than alligators. This is likely due to their larger size and more dominant behavior in the wild.

3. Can alligators and crocodiles interbreed?

No, alligators and crocodiles cannot interbreed because they are from different families of reptiles. Alligators belong to the Alligatoridae family, while crocodiles belong to the Crocodylidae family.

4. Which species is more widespread – alligators or crocodiles?

Crocodiles are more widespread than alligators, as they can be found in Africa, Asia, Australia, and the Americas. Alligators are only found in the Americas, primarily in the southeastern United States.

5. Are alligators and crocodiles endangered?

Both alligators and crocodiles have been endangered in the past due to habitat loss and hunting for their valuable hides. However, conservation efforts have helped to increase their populations in recent years. Some species of crocodiles, such as the saltwater crocodile, are still considered vulnerable or endangered due to ongoing threats from habitat loss and poaching.

6. Can alligators and crocodiles swim in the ocean?

Yes, both alligators and crocodiles are capable of swimming in the ocean. However, alligators typically prefer freshwater habitats and may not venture into saltwater environments unless forced to by circumstances such as hurricanes or flooding. Crocodiles, on the other hand, are known to live in both freshwater and saltwater habitats and can often be found near the coastlines of oceans and seas.

7. Which species is larger – alligators or crocodiles?

There is no clear winner in terms of size, as both alligators and crocodiles can grow to be very large. The largest species of crocodile is the saltwater crocodile, which can grow up to 23 feet long and weigh over 2,000 pounds. The largest species of alligator is the American alligator, which can grow up to 14 feet long and weigh over 1,000 pounds.

8. Are alligators and crocodiles dangerous to humans?

Both alligators and crocodiles have been known to attack humans if they feel threatened or if they mistake a person for prey. However, these attacks are relatively rare and can often be prevented by taking precautions such as avoiding swimming in areas known to be inhabited by alligators or crocodiles, and not approaching these animals in the wild.

9. What is the lifespan of alligators and crocodiles?

Alligators and crocodiles can both live for several decades in the wild, with some individuals living up to 70 years or more. The exact lifespan depends on factors such as species, habitat, and diet.

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