Reptiles are a class of animals that mostly live on land. Among them are lizards, crocodiles, snakes, and turtles. Only sea turtles and sea snakes live in the sea.
Historically, reptiles were considered one of five major groups of vertebrates because they have a spine in their back. However, this view is partly outdated. Today, scientists only call animals that have roughly the following similarities:
Reptiles have dry skin without mucus. This distinguishes them from amphibians. They also have no feathers or hair, which distinguishes them from birds and mammals. They also breathe with one lung, so they are not fish.
Most reptiles have a tail and four legs. Unlike mammals, however, the legs are not under the body, but rather on the outside on both sides. This type of locomotion is called the spread gait.
Their skin is protected with hard horny scales, which sometimes even form a real shell. However, because these scales do not grow with them, many reptiles have to shed their skin from time to time. That means they shed their old skin. This is particularly well known from the snakes. The turtles, on the other hand, keep their shell. He grows with you.
How do reptiles live?
Smaller reptiles feed on insects, snails, and worms. Larger reptiles also eat small mammals, fish, birds, or amphibians. Many reptiles also eat plants. Pure vegetarians are very rare. One of them is the iguana.
Reptiles do not have a specific body temperature. They adapt to the environment. It’s called “warmth”. A snake, for example, has a higher body temperature after extensive sunbathing than after a cold night. Then she can move much worse.
Most reptiles reproduce by laying eggs. Only a few species give birth to live young. Only the eggs of crocodiles and many tortoises have a fairly hard shell of lime like the eggs of birds. The rest of the reptiles lay soft-shelled eggs. These are often reminiscent of strong skin or parchment.
What internal organs do reptiles have?
Digestion in reptiles is almost the same as in mammals. There are also the same organs for this. There are also two kidneys that separate urine from the blood. The joint body outlet for feces and urine is called the “cloaca”. The female also lays her eggs through this exit.
Reptiles breathe with their lungs throughout their lives. This is another difference from amphibians. Most reptiles also live on land. Others, like the crocodiles, need to come up regularly for air. Turtles are an exception: They have a bladder in their cloaca, which they can also use to breathe.
Reptiles have a heart and a bloodstream. The heart is slightly simpler than that of mammals and birds, but more complicated than that of amphibians. The fresh blood with oxygen partly mixes with the used blood.