Skilled in leather "armor", or why the reptile requires mobility of the head

The first reptiles appeared on Earth several hundred million years ago. High organization allowed them to easily destroy invertebrate competitors, becoming sole rulers. From this time on, they began to flourish. The reign of reptiles on our planet has reached an unthinkable scale! They not only seized all the land, but also returned to the water, where they essentially pushed the ancient fish that reigned there. Moreover, reptiles have risen and into the air! Today reptiles are one of the most interesting, diverse and bright groups of animals on the planet Earth. It is interesting that to no class of animals people are not so contradictory as to reptiles: they are loved and at the same time hated, they cause non-childish interest and mystical horror. Externally, reptiles can vary significantly. Next, consider several types of their structure.

Lizard, snake and tortoiseshell types of the structure of reptiles

Perhaps the most common structure of reptiles is the so-called lizard type. Individuals related to him have a head, a cervical section, the trunk itself, a tail and four limbs. These are lizards, crocodiles, hatteria. The next type is snake. Probably, it is not necessary to explain that representatives of such appearance about extremities of speech simply can not be! These are flexible, with an elongated trunk, reptiles-snakes and many lizards that have lost their limbs. Representatives of the tortoise-type structure on all grounds fit the lizard structure, but only with one more feature - the body enclosed in a powerful shell. Of course, it's turtles. And now let's talk about the features that distinguish reptiles from inside their group, but, let's say, on the "world stage".

Skilful in armor

The main signs of reptiles, distinguishing them from other animals, are, of course, the features of movement on the ground and leather "armor." We already spoke about the first feature. Let's look at the second feature. The fact is that the skin of reptiles has a powerful stratum corneum, which forms shields and scales. Almost the entire body of the animal is covered with these "armor", even the eyelids and thin skin between the fingers! Such a leather "chain mail" - a very strong protection, and the shields, usually covering the top of the head - it's a kind of "helmet". Sometimes, under the horny scutes, bone plates grow. They like the armor protect the body of a reptile. That's how interesting are the crocodiles, lizards, snakes and other scaly land animals. But what about their flexibility? Does this "chain mail" not allow them even to turn their heads? Fortunately, this is not so! And why does reptile need mobility of the head? The ability to turn the head plays a big role in the hunting and safety of reptiles. Let's talk about this in more detail.

Why the reptile requires mobility of the head

As is known, reptiles are a continuation of amphibians that have emerged on land. One of the signs that distinguishes reptiles from amphibians is the presence of the cervical spine. For clarity, let's say that, for example, the frogs have no neck, and the head immediately passes into the trunk. The neck allows the reptile to turn its head to the side. You will ask, why does the motility of the head require reptiles? We answer with an example of a lizard's jump. Hearing a sound or a rustle of a moving object, the lizard immediately turns its head in its direction and sees everything that happens. If she is in danger - she runs away, if it is a potential prey, then the lizard grasps it, skillfully dealing with it. The ability to turn your head in different directions makes reptiles flexible, almost imperceptible, and also lightning-hunters. That's why reptiles need mobility of the head.

Interesting facts about snakes

Perhaps the most unique reptiles are snakes. They are adapted to crawl without the help of limbs and swallow large prey whole. Snakes radically differ from other reptiles by a very long and elastic trunk, which, in turn, leads to a very peculiar arrangement of internal organs. As we know, in ordinary vertebrates, many organs are paired and are symmetrically located. Snakes, from them, almost always remain only half, for example, many of them have only the right lung. And if there are paired organs, then they are at different ends of the long trunk. For example, the right kidney is shifted to the head, the left kidney to the tail! When we hear the word "snake", then involuntarily thoughts come to mind about the poisonous reptile. But today science knows more than 2700 kinds of snakes, and only 700 of them are poisonous.