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Dating back over 240 million years, the Crocodylia lineage has outlived the dinosaurs by over 65 million years. For many, crocodiles and alligators are easily interchangeable and often considered one and the same. In a way, it is easy to confuse these massive creatures. Both are viewed as large reptiles with toothy grins and rough, bumpy skin that have the ability to live on land or in water.
Similarities Between Alligators and Crocodiles
Among many physical similarities, both have eyes situated on the top of their heads. This enables them to look out for prey while remaining primarily underwater. Their eyes possess the same vertical pupils which helps them to open their eyes extra wide. This not only allows more light to pass through their eyes but also allows them to have night vision. Both alligators and crocodiles possess large, powerful tails. This assists them in swiftly propelling themselves through the water.
These features help both alligators and crocodiles to catch a variety of prey. This is why they are considered expert hunters. From fish to buffalo, these reptiles are able to eat whatever they can get their jaws on. Since their teeth are specialized particularly for spearing, it is very difficult for prey to escape once captured. If small enough, alligators and crocodiles often swallow their prey whole. Unfortunately for their prey, both alligators and crocodiles possess an unlimited supply of teeth. This means they are able to regrow teeth anytime they are lost.
Differences Between Alligators and Crocodiles
With a long list of similarities, you are probably wondering what the differences are between alligators and crocodiles. While these two reptile groups are closely related in many categories, there are major differences between them.
Snout and Jawline Shape
At first glance, people may believe that alligators and crocodiles have the same snouts, but this is not true. Alligators have a wider, U-shaped snout. This is different from the more pointed, V-shaped snout that crocodiles have. Both have razor-sharp teeth lining their snouts, which they use to capture and hold onto prey. The difference lies in how these teeth can be viewed.
When looking at an alligator, only the top teeth are visible. This is due to their upper jaw being wider than their lower jaw. As a result, the bottom teeth disappear when their mouths are no longer open. Both sets of teeth can be seen when Crocodiles close their mouths. This is due to both of their jaws being similar in width, allowing the top and bottom teeth to interlock.
Size and Weight
It is no doubt that both alligators and crocodiles are massive reptiles. With that being said, they do vary in size. While sizing depends on the particular species, crocodiles have a tendency to grow larger than the average alligator. Adult crocodiles can grow to approximately 19 feet long, while adult alligators can grow to 14 feet long.
A noticeable difference between alligators and crocodiles lies in the color and texture of their skin. Crocodiles are often lighter in color compared to alligators, often associated with being a light tan or olive color.
In contrast, alligators are often a mix between black and grey. The shade of their skin directly depends on the environment in which the alligator swims in. For example, they often appear darker when swimming in environments with overhanging trees due to tannic acid. In contrast, they appear greener in areas where algae is abundant.
Both crocodiles and alligators have sensory organs on their skin. These are seen in the form of small pits called integumentary sensor organs, otherwise known as ISO. This plays a role in helping both crocodiles and alligators locate their prey. ISO allows them to sense small pressure changes made throughout the water by other animals.
ISO appears as small dots that can be seen on both reptiles, but the main difference lies in the placement. On crocodiles, ISO covers the majority of the body. In comparison, it is only seen around the mouths of alligators.
A major difference between alligators and crocodiles can be found in the behavioral patterns. It is true that both reptiles are extremely dangerous, but their behavior differs from one another. Alligators are relatively timid compared to crocodiles. If approached, alligators have a tendency to try to escape rather than attack. However, they will attack if necessary, specifically if they are provoked, unexpectedly approached, or defending their young. Alligators are often more afraid of humans than the other way around. Regular contact, however, can cause them to lose that fear. Feeding them can result in them viewing humans as a source of food. This often results in them mistaking small children and family pets as prey.
In contrast, crocodiles are often bad-tempered and more likely to attack humans, often unprovoked. Following the Nile crocodile, Australian saltwater crocodiles are viewed as the most dangerous in the world. Thankfully, American crocodiles are less aggressive and more timid, rarely attacking humans. While you are more likely to be attacked by an alligator than a crocodile in America, individuals getting attacked by either are extremely unlikely to happen. In fact, it is believed that Americans are more likely to be killed by a shark than an alligator or crocodile.
In the United States, individuals are more likely to see an alligator than a crocodile. This is due to the notably larger alligator population in comparison to the crocodile population. There are approximately 3 million alligators to an estimated 2,000 crocodiles in the US.
One key difference between alligators and crocodiles is their preferred habitat. Crocodiles are often found in areas dominated by low-flowing rivers and grasslands. This includes Africa, Australia, Southeast Asia, North American, South America, and Central America. Unlike alligators, the crocodile’s lingual salt glands are extremely well-developed. As a result, they are able to expel excess salt from their bodies. This allows them to live in saline water for weeks at a time.
In comparison, alligators are more common in China and the Southeastern portion of the United States, including Florida and the Gulf Coast states. This is a result of their less developed lingual glands, which forces alligators to stick to freshwater habitats. Alligators can often be found in freshwater marshes and slow-moving streams, but some do reside in brackish water (a mixture of saltwater and freshwater). The only area in the world where both alligators and crocodiles can be found living together is the Florida Everglades.