In the modern world, it is generally accepted that crocodiles are distant relatives of dinosaurs. Indeed, in their appearance one can imagine what the ancient monsters were giants. Today, crocodiles are well studied and classified as a separate class. However, people often confuse which one to which. Crocodile - reptile or amphibian? What is the difference between these two classes? Let's take a closer look at them.
Class Amphibians
Amphibians, or this class is also called amphibians, is very different from all other vertebrates. The very first difference is that they have two stages of development. The first is that at a young age, amphibians look like fish. They also have a tail, gills and they are all born in the water. The second stage in development is the exit of amphibians from the water and the restructuring of the whole organism for life both in water and on land: the lungs develop, the tail disappears. The most obvious example in this case is a frog.
With such differences, why does the question arise: is a crocodile a reptile or an amphibian? The fact is that the crocodile lives in the water, has lungs and can also be considered to some extentamphibian. But he does not have stages of rebirth, like amphibians. Crocodiles are born already fully formed and not in water, but on land. And only after a while they seem to return to the aquatic environment. Now consider why the crocodile is a reptile.
Class Reptiles
The class of Reptiles includes not only crocodiles, but also snakes, turtles and lizards. All have similarities with amphibians and there are many differences. So, all reptiles are cold-blooded animals. Therefore, their main habitat is the tropics and subtropics. In addition, the body of reptiles is covered with scales that protect delicate skin. The crocodile has such strong skin that it is impossible to damage it just like that. Interestingly, unlike other types of reptiles, crocodiles do not shed, and their skin grows with them.
Another difference from amphibians is the structure of the skeleton. All reptiles have neck vertebrae that allow them to turn their heads. In addition, reptiles do not have skin respiration, like amphibians, but breathe due to a developed respiratory system. In all reptiles, fertilization occurs inside the body, unlike amphibians, and the young are born fully formed.
Features of the structure of the crocodile
The crocodile in its structure differs not only from amphibians, but also from most reptiles. The appearance of the crocodile is awesome, and it really looks like the dinosaurs that lived in antiquity. The length of the reptile is from 2 to 6 meters, it inspires fear. The head is arranged in a special way: it is flat,with a long snout, on which the nostrils are located. The eyes are located at the top, and when in the water, the crocodile can only expose the eyes and nostrils. In this case, it is very difficult to notice it.
In addition, the heart of a crocodile differs from a similar organ in other reptiles in that it has four chambers, not three. This indicates a more advanced circulatory system and brings the crocodile closer to mammals. But in the circulatory system of the crocodile there is a controlled system for mixing arterial blood with venous blood. This aids in the digestion process and prevents infection from being in dirty water.
Reproduction
Another sign by which you can determine whether a crocodile is a reptile or an amphibian is the method of reproduction. The female crocodile lays her eggs, but not in water, like amphibians, but on land. She buries them in the sand near the water. The female herself protects the nest from uninvited guests, being close to the masonry. Interestingly, all eggs hatch at the same time, and the sex of the babies depends on the ambient temperature. If the temperature exceeds 34 degrees, females will hatch, and if it is between 30 and 34, then males.
Just before they are born, little crocodiles give their mother a signal, and she carefully digs out the masonry, helping them out of the nest. All other reptiles do not do this. At the same time, the crocodile also carries its babies in its mouth to the water. One can imagine how thesehuge jaws gently take crocodiles and move them into the pond. Also, sometimes a crocodile helps to get to the water and newborn turtles.
Types of crocodiles
There are 21 species of crocodiles in nature. All of them differ in size, habitat and head structure. Most often they confuse the crocodile and alligator. An interesting point: they differ in the structure of the muzzle. In a crocodile, it is sharp, and in an alligator, it is more blunt. Teeth with a closed mouth are visible only in crocodiles. The heart of a crocodile pumps blood faster, and due to this, s alt metabolism is faster than that of alligators. This feature allows crocodiles to live not only in fresh water, but also in the sea.
There are small crocodiles, such as caimans, that can be kept at home. This often happens because the caiman is able to adapt well to any conditions. The only thing is that he lives only in clean water, and this is easy to create in a house or a zoo.
Perhaps this article helped you figure out the question: is a crocodile a reptile or an amphibian?
