What is the movement of animals crawling, and what do reptiles rely on?

There are many kinds of crawling movements, and different kinds of animals crawl in different postures, and this is not absolutely fixed.

a.Fins. b.Limbs collapsed.

c.Wing. Correct answer to the case: Duan shirt Shen b

Categories: Life.

Analysis: In the process of life evolution, reptiles occupy an extremely important position. Because its embryos can develop in amniotic eggs laid on land, its reproduction and development are free from dependence on the external water environment. It is a true terrestrial vertebrate.

Snakes, lizards, turtles, turtles, crocodiles, etc., which are common to people, are all reptiles. Their main characteristics are: oviparous, amniotic eggs, warm, dry, covered with scales or decks, and the skeleton also has a series of characteristics adapted to life on land.

The fingers have claws, which are good for land crawling and climbing.

More than 100 million years ago, in the Mesozoic Era, reptiles flourished and dominated the earth, known as the "age of dinosaurs". About 65 million years ago, the dinosaurs became extinct from the earth, and the living reptiles are only a small remnant, but despite this, the reptiles that live on the earth are still colorful.

There are 5,700 species of reptiles in the world. It is mainly divided into four categories: turtles, beaks, scales (lizards, snakes), and crocodiles.

Turtles and turtles are the oldest group of reptiles living on Earth. It is almost a reptile of the same age as the dinosaurs, and its evolution is extremely slow, and it is a reptile that lives on land, water, and in the ocean. Turtles that live on land have thick limbs and blunt claws.

Sea turtles, on the other hand, have pulpy limbs that are suitable for swimming, and they all have hard shells to protect their internal organs. Beak leader, is a primitive terrestrial species. The outside of the body is covered with fine scales, and the beak is long like a bird's beak, so it is called a beak-headed lizard.

There is only one remaining species of this order, which is found in New Zealand. Lepids are a group of terrestrial, aquatic, arboreal and burrowing groups, and are the most numerous and diverse group of reptiles. It is distributed all over the world.

Lizard suborder is a small and medium-sized reptile, in this group, the largest is the monitor lizard, up to 4 meters long, weighing 25 kilograms, the smallest is the gecko is only 3 4 millimeters, more than 10 grams, but they also occupy an important place in nature. The suborder snake, as small as a millimeter and as large as 11 meters, burrows and climbs, it is characterized by a high degree of myopia, but the tongue is a very sensitive chemical detector that can detect changes in the chemicals in the surrounding air.

There are many kinds of them, poisonous snakes and non-venomous snakes, there are aquatic snakes and terrestrial and arboreal snakes, as well as land, tree, water, and three-way snakes.

There are 391 species of reptiles in China. Yunnan accounts for the number of species in the country. Due to long-term overhunting, the wild population of the dusty reptile has become seriously endangered and in decline.

Reptiles are scaly, egg-laying (some are reborn in the mother's body, but it is also an egg) and the eggshell is harder and less fragile. Inability to regulate one's own body temperature. Amniotic animals, which belong to the quadruped class, are the general name for all species of sauriformes and zygomorpha except birds and mammals, and they are born with all the skills of their parents, such as crocodiles, turtles, turtles, lizards, geckos, and snakes.

Reptiles are animals of the class Reptiles of the phylum Vertebrates.

The characteristics are: oviparous, belly crawling, cold-blooded.

Representative animals: dinosaurs (extinct), lizards, snakes, turtles, soft-shelled turtles, crocodiles, etc.