The topic of this article is reptiles. Species, origins, habitats, as well as some other facts about them will be presented in it.
The word "reptile" comes from a Latin term meaning "to crawl", "to crawl". This implies the nature of the movement of representatives of this class. It should be noted, however, that not all reptiles are animals that can only crawl. There are some who are good at jumping, running, swimming and even practically flying, gliding like flying squirrels.
Ancient reptiles
These animals lived long before humans appeared on our planet. The reptiles living on Earth today are only relics (insignificant remnants) of a class that was very diverse and rich in the past. We are talking about reptiles that reached their peak in the Mesozoic era (approximately 230-67 million years BC). Ancient reptiles were represented in a huge number of forms. Some of their species lived on land. One can note among them large predatory tarbosaurs and giantherbivorous brontosaurs. Others, such as ichthyosaurs, lived in the water. Still others could fly like birds. The amazing world of ancient reptiles has not yet been fully explored. Perhaps in the near future, scientists will encounter new discoveries.
In 1988, the remains of reptiles were discovered in Scotland. According to experts, these reptiles lived 340 million years ago. It was, as it turned out, the most ancient species of fossil reptiles known today. Their body was only 20.3 cm long.
The origin of ancient reptiles
Ancient reptiles originated from ancient amphibians. This event was the next step in the adaptation of vertebrates to life on land. Today, amphibians and reptiles coexist. Amphibians are otherwise called amphibians, and reptiles are called reptiles.
Groups of modern reptiles
Reptiles (modern) include the following groups.
1. Crocodiles. These are large animals with a lizard-like body. There are only 23 species of them, which include real crocodiles, as well as alligators, caimans and gharials.
2. Beakheads. They are represented by just one species of tuatara called Sphenodon punctatus. These reptiles (a photo of one of them is presented below) in appearance resemble large lizards (up to 75 cm) with a massive body, five-fingered limbs and large heads.
3. Scaly. This group of reptiles is the most numerous. It includes 7600 species. These include, for example, lizards - the most numerous group of reptilesfrom modern ones. This includes: monitor lizards, iguanas, scale-footed, skinks, agamas, chameleons. Lizards are a specialized group of animals that lead a primarily arboreal lifestyle. The scaly ones also include snakes - legless reptiles, as well as amphisbaenas - creatures with a worm-like body and a short tail that looks like a head end. Amphisbaena are adapted for a burrowing lifestyle. They very rarely appear on the surface. These reptiles spend most of their lives underground or in the nests of termites and ants that amphisbaena feed on. They usually lack limbs. Representatives belonging to the genus Bipes have only front legs. They can move along earthen passages and tail first. Because of this, they are also called doubles. "Amphisbaena" is translated from Greek as "moving in both directions".
4. Another group is turtles. Their bodies are surrounded by shells from below, from the sides and from above. The shell includes the abdominal (plastron) and dorsal (carapace) shields, which are connected by a bone jumper or tendon ligament. There are about 300 species of turtles.
Together with mammals and birds, reptiles are combined into one group of higher vertebrates.
Where do reptiles live?
Mostly reptiles lead a terrestrial way of life. These are creatures that prefer open landscapes warmed by the sun, including almost devoid of vegetation, waterless deserts. However, many turtles and all crocodiles live in rivers, lakes or swamps. Some snakes and partturtles also live permanently in the seas.
Reptile skin, unfortunately, is now used for the production of leather goods. It is highly valued, and because of this, many representatives of reptiles suffer. Their future is in our hands.
Crocodile habitats
Crocodiles are common in all countries of the tropics. Basically, these reptiles are animals living in high-water swamps, lakes and rivers. They usually spend most of the day in the water. Crocodiles come to the coastal shallows in the morning, and also in the late afternoon, in order to bask in the sun. S alty sea water is tolerated by relatively few species. The combed crocodile swims especially far into the open sea - up to 600 km from the coast.
Hatteria and lizard habitats
The tuatara today are preserved only on rocky islets located near New Zealand. A special reserve was created here for their sake.
Lizards are distributed almost all over the planet, except for cold zones. Some types of mountains rise to the border of eternal snow, for example, in the Himalayas - up to a height of 5.5 km above sea level. Most lizards lead a terrestrial lifestyle.
However, some of them climb trees or bushes, such as roundheads. Others may live permanently in trees and are capable of gliding flight. Agamas and geckos living in rocks can move along vertical surfaces. Also, some lizards live in the soil. They usually lack eyes, andtheir bodies are elongated. The sea lizard lives near the surf line. She has excellent swimming skills. She spends a lot of time in the water, eating seaweed.
Where do snakes and turtles live?
Snakes are everywhere on Earth, except for New Zealand, the polar regions and some oceanic islands. All of them swim well, there are even species that spend almost all or all of their time in the water. These are sea snakes. Their tails are compressed from the sides in a paddle-like manner. Due to the transition of snakes to a burrowing lifestyle, some of them have reduced their eyes and disappeared under the shields, and their tails have also shortened. These are narrow-mouthed snakes and blind snakes.
Freshwater and land turtles are found on many islands, as well as on all continents except Antarctica. Their habitats are very diverse. These are tropical forests, hot deserts, rivers, lakes and swamps, expanses of the ocean and coasts of the seas. Sea turtles spend their entire lives in the water. They come ashore only to lay eggs.
The largest snakes
The largest modern snakes are anacondas (pictured above) and reticulated pythons. In length they reach 10 meters. In Eastern Colombia, a specimen of an anaconda was found, unique in size - 11 m 43 cm. The Brahmin blind is the smallest snake. Its body length is no more than 12 cm.
Size of crocodiles
The largest of the crocodiles are combed and Nile. In length, they reach 7 m. 1.2 m for females and 1.5 m for males is the maximum body length of a smooth-fronted caiman,the smallest among other types of crocodiles.
The biggest and smallest turtles
The largest of modern turtles is considered to be a sea leatherback. Its length can exceed 2 meters. In the UK, on the coast in 1988, the dead body of a male of this species of turtle was found, which had a width of 2.77 m and a length of 2.91. The Muscovy turtle is the smallest of all species. On average, the length of her carapace is 7.6 cm.
Lizard sizes
Among the lizards, the Virginian round-toed geckos are considered the smallest. Only 16 mm is the length of their bodies (excluding the tail). Without a doubt, the largest lizard is the Komodo dragon (its photo is presented below).
The length of his body reaches three or even more meters. The El Salvador slender-bodied monitor lizard, which lives in Papua New Guinea, reaches 4.75 m in length, but about 70% of its length falls on the tail.
Reptile body temperature
Like amphibians, reptiles do not have any kind of constant body temperature. Their life activity therefore depends to a large extent on the ambient temperature. For example, in dry and warm weather, they are especially active and at this time they often catch the eye. On the contrary, in bad weather and cold they become inactive and rarely leave their shelters. At temperatures close to zero, reptiles fall into a stupor. That is why they are few in the taiga zone. There are only about 5 types of them here.
Reptiles can control their body temperature by simply hiding from hypothermiaor overheating. Hibernation, for example, allows reptiles to avoid the cold, and the heat of the day - night activity.
Features of breathing
Reptiles (a photo of some of them is presented in this article), unlike amphibians, breathe only with the lungs. Their lungs retain a bag-like structure, but reptiles have a much more complex internal structure than amphibians. The folded cellular structure has the inner walls of their lung sacs. They resemble honeycombs. This significantly increases the respiratory surface in reptiles. Unlike amphibians, reptiles do not blow air through their mouths. However, for most of them, breathing of the so-called "suction" type is characteristic. They exhale and inhale air through the nostrils by constricting and expanding the chest. The act of breathing is carried out with the help of the abdominal and intercostal muscles.
Turtles, however, have ribs that are immobile due to their shell, so their species have evolved a different way of ventilation than other reptiles. They force air into their lungs by swallowing it or by making pumping movements with their front legs.
Reproduction
Reptiles breed on land. At the same time, unlike amphibians, they have direct development, that is, without a larval stage. Reptiles usually lay large eggs rich in yolk with shell and amniotic (embryonic) membranes, which protect embryos from mechanical damage and water loss, and also provide gas exchange and nutrition. By the time they hatch, they reach a considerable size.young reptiles. These are already miniature copies of adults.
