The topic of this article is reptiles. Species, origin, habitat, as well as some other facts about them will be presented in it.
The word "reptiles" comes from the Latin term meaning "crawl", "crawl" in translation. From here follows 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, run, swim, and even practically fly well, planning like flying squirrels.
Ancient reptiles
These animals lived long before the appearance of man on our planet. The reptiles living on Earth today are only relics (insignificant remnants) of a very diverse and rich class in the past. We are talking about reptiles that reached their greatest prosperity in the Mesozoic era (approximately 230-67 million years BC). A huge number of forms were represented by ancient reptiles. Some of their species lived on land. Among them, large predatory tarbosaurs and giant herbivorous brontosaurs can be noted. 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 face 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 fossil reptile species known today. Their body in length was only 20.3 cm.
The origin of ancient reptiles
From ancient amphibians descended ancient reptiles. This event was the next step in the process of 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
The following groups belong to reptiles (modern).
1. Crocodiles . These are large animals with a lizard-like body. There are only 23 species, including real crocodiles, as well as alligators, caimans and gavials.
2. Beak-headed . They are represented by just one type of hatteria 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 modern reptiles. These include: monitor lizards, iguanas, scales, skinks, agamas, chameleons. Lizards are a specialized group of animals that leads mainly a tree lifestyle. Snakes - legless reptiles, as well as amphisbens - creatures with a worm-like body and a short tail that resembles the head end in appearance, also belong to scaly ones. Amphisbens are adapted for leading a digging 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 amphisbens feed on. They usually have no limbs. Representatives belonging to the genus Bipes have only front legs. They can move along earthen passages and tail forward. Because of this, they are also called dvuhhodki. Amphisbens 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 carapace 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 combined into one group of higher vertebrates.
Where do reptiles live?
Most of them are terrestrial reptiles. These are creatures who prefer open landscapes warmed by the sun, including waterless deserts almost devoid of vegetation. However, many turtles and all crocodiles live in rivers, lakes or swamps. Some snakes and some turtles also constantly live in the seas.
Unfortunately, reptile skin is now used to make leather goods. It is very much appreciated, and many reptiles suffer because of this. 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 water. Crocodiles go to the coastal shallows in the morning, and also in the late afternoon, in order to bask in the sun. Relatively few species are tolerant of saltwater. Saltwater crocodile swims in the open sea especially far - up to 600 km from the coast.
Habitat and lizard habitats
Hatteria today survived 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 belts. Some mountain views rise to the border of eternal snow, for example, in the Himalayas - up to 5.5 km above sea level. Most lizards lead the land lifestyle.
However, some of them climb trees or bushes, such as round-headed. Others can live permanently on trees and have the ability to plan a flight. Agamas and geckos living in the rocks can move on vertical surfaces. Also, some lizards live in the soil. They usually have no eyes, and their bodies are elongated. Sea lizard lives at the surf line. She has a well-developed ability to swim. She spends a lot of time in water, eats seaweed.
Where do snakes and turtles live?
Snakes are common throughout the world, except for New Zealand, the polar regions and some oceanic islands. They all swim well, there are even species that spend almost all or all of their time in water. These are sea snakes. Their tails are laterally compressed oarly. Due to the transition of snakes to burrowing lifestyles, some of them have reduced eyes and disappeared under the shields, as well as shortened tails. These are narrow-snakes and blindfolk.
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, open spaces of the ocean and coast of the seas. Sea turtles spend their whole lives in water. They go ashore only for laying eggs.
The largest snakes
The largest snakes from modern ones are anacondas (pictured above) and reticulated pythons. In length they reach 10 meters. In East Colombia, a copy of the anaconda was found, unique in size - 11 m 43 cm. The Brahmin blind mole is the smallest snake. Its body length is not more than 12 cm.
Crocodile sizes
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-faced caiman, the smallest among other species of crocodiles.
The biggest and smallest turtles
The largest of modern turtles is considered marine leathery. Its length can exceed 2 meters. In the UK, on the coast in 1988, a dead body of a male of this species of tortoise was discovered , which was 2.77 m wide and 2.91 long. The musk turtle is the smallest among all species. On average, the length of her carapace is equal to 7.6 cm.
Lizard sizes
Among the lizards, the smallest are virgin round-toed geckos. Only 16 mm is the length of their bodies (excluding the tail). Without a doubt, the largest lizard is the Komodo lizard (its photo is presented below).
The length of his body reaches three and even more meters. The thin-bodied lizard of El Salvador living in Papua New Guinea reaches 4.75 m in length, but at the same time about 70% of its length falls on the tail.
Reptile body temperature
Like amphibians, reptiles do not have any constant body temperature. Their vital activity therefore depends to a large extent on the surrounding temperature. For example, in dry and warm weather they are especially active and often catch their eye at this time. On the contrary, in inclement weather and cold they become inactive and rarely leave their shelters. At temperatures close to zero, reptiles become numb. That is why they are not numerous in the taiga zone. There are only about 5 species.
Reptiles can control their body temperature simply by taking cover from hypothermia or overheating. Winter hibernation, for example, allows reptiles to avoid colds, and daytime heat - night activity.
Breathing features
Reptiles (photos of some of them are presented in this article), unlike amphibians, breathe only light. Their lungs retain a bag-like structure, but reptiles have a much more complicated internal structure than amphibians. The folded cellular structure has inner walls of their pulmonary sacs. They resemble a honeycomb. This significantly increases the respiratory surface in reptiles. Unlike amphibians, reptiles do not blow air with 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 narrowing and expanding the chest. An act of breathing is performed using the abdominal and intercostal muscles.
However, in the turtles the ribs are motionless due to the presence of the shell, therefore, the species belonging to them developed a different ventilation method than the rest of the reptiles. They drive air into the lungs by swallowing it or by pumping movements with their front legs.
Breeding
Reptiles breed on land. Moreover, they, unlike amphibians, have direct development, that is, without a larval stage. Reptiles usually lay large yolk-rich eggs with shell and amniotic (germ) shells, which protect embryos from mechanical damage and water loss, as well as provide gas exchange and nutrition. By the time of hatching young reptiles reach considerable size. These are already miniature copies of adults.