Reptiles are ... Amphibians and reptiles. Ancient reptiles

The subject of this article is reptiles. Species, origin, habitats, as well as some other facts about them will be presented in it.

The word "reptiles" comes from the Latin term meaning "to grovel", "creep" in translation. Hence 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 those who jump well, run, swim and even fly, planning as flying squirrels.

Ancient reptiles

These animals lived long before the appearance of a human on our planet. The reptiles living on the Earth today are only relicts (minor remains) of a very diverse and rich in the past class. It is a question of reptiles, the greatest flowering reached in the Mesozoic era (approximately 230-67 million years BC). An enormous number of forms were represented by ancient reptiles. Some of their species lived on land. It is possible to note among them large predatory tarbosaurs and giant herbivorous bronzosaurs. Others, such as ichthyosaurs, lived in water. Others could fly like birds. The amazing world of reptiles of antiquity has not been studied to the end. Perhaps in the near future, scientists will face new discoveries.

In 1988, the remains of reptiles were found in Scotland. According to experts, 340 million years ago these reptiles lived. It was, as it turned out, the oldest known species of fossil reptiles today. Their body was only 20.3 cm long.

Origin of ancient reptiles

From ancient amphibians, ancient reptiles have occurred. This event was the next stage in the adaptation to life on land of vertebrates. Today amphibians and reptiles coexist. Amphibians are otherwise called amphibians, and reptiles are reptiles.

Groups of modern reptiles

Reptiles (modern) include the following groups.

1. Crocodiles . These are large animals that have a lizard-like body. They are only 23 species, including real crocodiles, as well as alligators, caimans and gavials.

2. Blueheads . They are represented by only one species of gatteria 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 largest group of reptiles from the modern. This includes: lizards, iguanas, cheshuenogi, skinks, agams, chameleons. Lizards - this is a specialized group of animals, which leads in the main tree way of life. Scales also include snakes - legless reptiles, as well as amphibians - creatures with a vermicular body and a short tail, reminiscent of the externally leading end. Amphibians are adapted to conduct a digging lifestyle. They very rarely appear on the surface. These reptiles spent most of their life under the ground or in the nests of termites and ants, with which amphibians feed. They usually have no limbs. Representatives belonging to the genus Bipes have only front legs. They can move on earth motions and tail forward. Because of this, they are also called double-headed. "Amfisbenes" is translated from Greek as "moving in both directions."

4. Another group is turtles . Their bodies from below, from the sides and from above surround the shells. The shell includes the abdominal (plastron) and dorsal (carapace) shields, which are connected by a bone jumper or tendon ligament. Turtles number about 300 species.

Together with mammals and birds, reptiles are united in one group of higher vertebrates.

Where do reptiles live?

Most of them lead a terrestrial lifestyle of reptile. These are creatures who prefer sun-warmed open landscapes, including virtually desertless desertless deserts. However, many turtles and all crocodiles live in rivers, lakes or swamps. Some snakes and some turtles also live in the seas permanently.

Reptile skin, unfortunately, is now used for the manufacture of leather products. It is very appreciated, and because of this many representatives of reptiles suffer. Their future is in our hands.

Habitat of crocodiles

In all countries of the tropics are widespread crocodiles. In general, these reptiles are animals living in marshy wetlands, lakes and rivers. They usually spend most of the day in the water. Crocodiles go to the coastal shoals in the morning, and also towards evening, in order to bask in the sun. To the salt water of the sea are tolerated relatively few of their species. The combed crocodile swims into the open sea especially far - up to 600 km from the shore.

Habitat of gatteries and lizards

Gatteria today are preserved only on rocky islets located near New Zealand. A special reserve was created here for them.

Lizards are spread almost all over the planet, except for cold belts. Individual species in the mountains rise to the limit of eternal snow, for example, in the Himalayas - to a height of 5.5 km above sea level. The terrestrial lifestyle is led by most lizards.

However, some of them climb trees or bushes, for example round heads. Others can live permanently on trees and have the ability to plan a flight. Agamas and geckos living in rocks can move along vertical surfaces. Also, some lizards live in the soil. They usually have no eyes, and their bodies are elongated. The sea lizard lives near the surf line. She has an excellent ability to swim. She spends a lot of time in the water, eats seaweed.

Where do snakes and turtles live?

Snakes, except New Zealand, polar regions and some oceanic islands, are distributed everywhere on Earth. All of them swim well, there are even species that practically all or all the time spend in the water. These are sea snakes. Their tails are compressed from the sides in a paddle. Due to the transition of snakes to the burrowing way of life, some of them have diminished their eyes and disappeared under the shields, and also shortened their tails. They are narrow-snake and blind.

Freshwater and land tortoises are found on many islands, as well as on all continents, except Antarctica. Their places of residence are very diverse. These are tropical forests, hot deserts, rivers, lakes and swamps, expanses of the ocean and seashores. All life sea turtles spend in the water. They go ashore only to lay eggs.

The largest snakes

The largest snakes from modern ones are the anacondas (pictured above) and mesh pythons. In length they reach 10 meters. In East Colombia, a specimen of anaconda was found, unique in size - 11 m 43 cm. The Brahmin blind is the smallest snake. Its length is no more than 12 cm.

The sizes of crocodiles

The largest of the crocodiles are the comb 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-legged caiman, the smallest among other crocodile species.

The largest and smallest turtles

The largest of modern turtles is sea leather. Its length can exceed 2 meters. In Britain, on the shore in 1988, a dead body of a male of this turtle species was found , having a width of 2.77 m and a length of 2.91 m. The musk tortoise is the smallest among all species. On average, the length of its carapace is 7.6 cm.

Dimensions of lizards

Among the lizards, the smallest are the virgin round-headed geckos. Only 16 mm is the length of their bodies (without taking into account the tail). No doubt, the largest lizard is the Komodo monitor (photo below).

The length of his body reaches three and even more meters. Living in Papua New Guinea, the slender calf of El Salvador reaches 4.75 m in length, but about 70% of its length falls on the tail.

Body temperature of reptiles

Like amphibians, reptiles do not have any constant body temperature. Their vital activity therefore depends largely on the ambient temperature. For example, in dry and warm weather, they are particularly active and at this time often come to their eyes. On the contrary, in bad weather and cold they become inactive and rarely come out of their shelters. At temperatures close to zero, reptiles fall into a stupor. That is why they are few in the taiga zone. Here there are only about 5 species.

Reptiles can control the temperature of their bodies, simply by hiding from hypothermia or overheating. Winter hibernation, for example, allows reptiles to avoid cold weather, and daytime heat - night activity.

Features of breathing

Reptiles (a photo of some of them is presented in this article), unlike amphibians, breathe only lungs. At them lungs keep a sack-like structure, however at reptiles the internal structure is much more complex, than at amphibians. Folded honeycomb structure has internal walls of their lung bags. They resemble bee honeycombs. This significantly increases the respiratory surface in reptiles. Unlike amphibians, reptiles do not inject the mouth with the mouth. However, for most of them, respiration of the so-called "suction" type is characteristic. They exhale and inhale air through the nostrils with the help of constriction and expansion of the chest. An act of breathing with the help of the abdominal and intercostal musculature is performed.

However, in the turtles the ribs are immovable due to the presence of the shell, so the species belonging to them developed a different way of ventilation than the rest of the reptiles. They pound into the lungs of the air with the help of its ingestion or by making the front legs pumping.

Reproduction

Reptiles reproduce on land. In this case, in contrast to amphibians, they have a direct development, that is, without a larval stage. Reptiles usually lay eggs rich in yolk with shell and amniotic (germinal) membranes that protect embryos from mechanical damage and loss of water, and also provide gas exchange and nutrition. By the time of hatching, young reptiles have reached a significant size. These are already miniature copies of adults.