The origin of birds: features, interesting facts and description. Meaning and protection of birds

Birds are feathered friends of man. Their role in nature is invaluable. About their origin, meaning and protection, read in the article.

Birds: a general characteristic

Feathered are highly organized warm-blooded animals. In nature there are nine thousand species of modern birds. The following are the characteristic features of the class:

• Feathers.
• A hard beak from the cornea.
• No teeth.
• A pair of forelimbs is turned into wings.
• The chest, pelvic girdle and the second pair of extremities have a special structure.
• The heart consists of four chambers.
• There is an air bag.
• The bird hatchs eggs.

Birds, the general characteristics of which are presented above, thanks to the above features are able to fly. This distinguishes them from other classes of vertebrate animals.

Appearance on the ground

The origin of birds is explained by several theories. According to one of them, residing of birds on trees is supposed. First they jumped from branch to branch. Then they slipped, then made small flights within the same tree and finally learned how to fly in the open space.

Another theory suggests that the origin of birds is associated with the ancestors of birds that were reptiles with four legs. Evolving, the scales became feathers, which allowed reptiles to make a jump, flying a short distance. Later, the animals learned to fly.

Origin of birds from reptiles

Based on this theory, we can say that the ancestors of the birds were also creeping reptiles. At first their nests were on the ground. This attracted predators, which constantly destroyed the nests along with the chicks. Caring for their offspring, reptiles settled in the thick of branches of trees. Simultaneously, hard eggshells were formed on the eggs. Before that they were covered with a film. Instead of scales, feathers appeared, which served as a source of heat for the eggs. The limbs became longer and covered with plumage.

The origin of birds from ancient reptiles is obvious, according to scientists. The ancestors of the birds begin to care for their offspring: they feed the young in the nest. For this, solid food was crushed into small pieces and put it into the kids' beaks. Possessing the ability to fly, primitive birds of the ancient period of time could better defend themselves from the attack of their enemies.

Ancestors - waterfowl

The origin of birds, according to another theory, is related to their waterfucking brethren. To its existence this version is due to the remains of ancient birds that were found in China. According to scientists, they were waterfowl and lived more than one hundred million years ago.

According to theory, birds and dinosaurs lived together for sixty million years. Among the findings were feathers, muscles, membranes. Exploring the remains, paleontologists made the following conclusion: the ancestors of ancient birds swam. To get food out of the water, they dived.

What are the similarities between birds and reptiles?

If you study the origin of birds, the similarities between them and representatives of other classes are easy to find. Plumage is the most noticeable feature of the appearance of birds. Other animals have no feathers. This is the difference between birds and other animals. Signs of similarity are as follows:

• The fingers of the feet and the nap are covered in many birds with scales from the cornea and with scutes, as in reptiles. Hence, scales on legs can replace feathers. It is characteristic that the rudiments of feathers in birds and reptiles do not differ. Only the birds then develop feathers, while the reptiles have scales.
• Investigating the origin of birds, features in whose similarity to reptiles are incredible, scientists have determined that the jaw apparatus is more noticeable. Only in birds it turned into a beak, while in reptiles it remained the same as in a turtle.
• Another sign of the similarity of birds and reptiles is the skeletal structure. The skull and spine are articulated by only one tubercle located in the occipital region. Whereas in mammals and amphibians in this process, two tubercles are involved.
• The location of the pelvic girdle of birds and dinosaurs is the same. This is evident from the skeleton of the fossil. This arrangement is associated with the load on the pelvic bone when walking, since only the hind limbs are involved in holding the body.
• Birds and reptiles have a four-chambered heart. In some reptiles the septum of the chambers is incomplete, and then the arterial and venous blood are mixed. Such reptiles are called cold-blooded. Birds have a higher organization, in comparison with reptiles, they are warm-blooded. This is achieved by removing the vessel that carries the blood from the vein into the aorta. In birds it does not mix with arterial.
• Another similar feature is the incubation of eggs. This is typical for pythons. They lay about fifteen eggs. Snakes curl over them, forming a kind of canopy.
• Most birds look like reptiles, which in the first stage of their development are similar to fish-like creatures with tails and gills. This makes a similar chick future to other vertebrates in the early stages of development.

Differences of birds from reptiles

When paleontologists study the origin of birds, they compare the facts and findings collected in grains, and find out what birds are like reptiles.

What are their differences, read below:

• When the birds had the first wing, they began to fly.
• The body temperature of birds does not depend on external conditions, it is always constant and high, while reptiles fall asleep during the cold.
• In birds, many bones are spliced, they are distinguished by the presence of a pint.
• The birds have air sacs.
• Birds build nests, incubate eggs and nest chicks.

Pervopitets

At present, fossil remains of ancient birds have been found. After careful research, the scientists came to the conclusion that they all belong to the same species that lived one hundred and fifty million years ago. These are archeopteryxes, which in translation means "ancient Persians". Their difference from today's birds is so obvious that the archeopteryxes were identified in a separate sub-class - the lizard-tailed birds.

Little studied ancient birds. The general characteristic is reduced to the definition of appearance and some features of the internal skeleton. The pioneer was of a small size, about like a modern magpie. Her forelegs had wings, the ends of which ended in three long fingers with claws. The weight of the bones is large, so the ancient bird did not fly, but only crawled.

The habitat is coastal areas of marine lagoons with dense vegetation. The jaws had teeth, and the tail - vertebrae. Between Archeopteryx and modern birds, no connections are established. The priests were not the direct ancestors of our birds.

Meaning and protection of birds

The origin of birds is of great importance in biogeocenoses. Birds are an integral part of the biological chain and participate in the circulation of living matter. Feeding of herbivorous birds are fruits, seeds are green vegetation.

Different birds play different roles. Carnivorous - eat seeds and fruits, separate species - store them, carrying them over long distances. On the way to the storage site, the seeds are lost. This is how the plants settle. Some birds have the ability to pollinate them.

Great role in the nature of insectivorous birds. They control the number of insect populations by eating them. If there were no birds, the destructive activity of insects would be irreparable.

Man, as far as possible, protects birds and helps them survive in severe winters. People everywhere hang temporary nests. In them settle tits, flycatchers, azure. Winter periods are characterized by the lack of natural food for birds. Therefore, birds should be fed, filling the nest with small fruits, seeds, bread crumbs. Individual birds refer to commercial species: geese, ducks, hazel grouses, wood grouse, black grouse. Their value for man is great. Sports interest is represented by woodcocks, waders, snipe.

Interesting Facts

From the depths of the centuries: the body and legs of Archeopteryx were covered with long feathers, three and a half centimeters. It can be assumed that the birds did not wave their feet. Feathers inherited from ancestors who lived in more ancient times and used all four wings during the flight.

Today: filling the nesting of birds with food, you need to make sure that salt does not get there. It is a white poison for birds.