Birds. Archeopteryx. The main periods of the annual cycle

27.04.2020

REPORT ON NATURAL SCIENCE

Performed:

student 6 "A" class

Stolbennikova Karina

Archeopterix (Archaeopterix lithographica), an extinct animal of the lizard-tailed subclass, a small feathered dinosaur, a possible ancestor of birds. Archeopteryx lived in the Jurassic period. An Archeopteryx skeleton with well-preserved feathers was first found in 1861. Five such Archeopteryx skeletons are known, two of which were found in museums (the Netherlands and Germany), where they were kept as pterosaur and dinosaur skeletons.

Archeopteryx length - 45 cm, weight - 300 g (magpie size). It had teeth and a long bony tail adorned with two rows of feathers. Each wing of Archeopteryx had three clawed fingers. It is believed that he used them to climb trees, from where he periodically planned to the ground. He could take off from the ground, using strong gusts of wind. Archeopteryx had beak-like, toothy jaws and fed on insects.

The structure of Archeopteryx combines signs of reptiles (a skull with two temporal arches, teeth in the alveoli, a small reptilian brain, abdominal ribs, amphicoelous vertebrae, a long tail consisting of about 20 vertebrae, no horn cover of the beak) and birds (the body is covered with feathers, the flight feathers of the wings are large, asymmetrical in structure, the bones of the limbs are partially pneumatized). Based on the study of Archeopteryx, ideas about mosaic evolution were developed. Most researchers believe that Archeopteryx is the direct ancestor of birds, descended from theropod dinosaurs or from ancient bipedal crocodiles, or from pseudosuchians. However, some researchers believe that Archeopteryx is a lateral branch of reptiles, showing a possible development path from them to birds. The Berlin specimen of Archeopteryx is described as a separate genus and species - Archeornis (Archaeornis siemensi), but it is more common to attribute all Archeopteryx finds to one species.

The discovery of Archeopteryx was made immediately after the publication of Charles Darwin's book On the Origin of Species and ideally confirmed it. Such a coincidence has repeatedly caused discussions about the authenticity of the finds, in particular, a copy of the British Museum, but a thorough examination of the 1980-1990s refuted all doubts.

The most "convincing" example of an intermediate link between two large groups of animals is generally recognized as the "great bird" - Archeopteryx. Since 1861, in addition to one individual feather, five more or less well-preserved petrified specimens of these birds have been found in the Solnhofen limestone slabs, to which a recent sixth find has been added. They clearly show both signs of reptiles and signs of birds. Typical features of reptiles are a jaw filled with teeth, the absence of a keel on the sternum, the structure of claws and vertebrae, free ribs without hook-shaped processes, and an elongated caudal region of the vertebral column. They are contrasted with typical features of birds, such as plumage, the skeleton of the arms, pelvis and legs.

Hoatzin (n (Opisthocomus hoatzin) - a modern bird, in some ways similar to Archeopteryx. With the help of specific claws on the wings, hoatzin chicks can climb branches, and in case of danger they prefer to “sit out” in the water.

Feathers are a characteristic feature of birds. The fossil, which is interpreted as the precursor of birds, must have probably been distinguished by the presence of "great feathers", i.e. formations that would serve as a bridge in the process of transformation, development of feathers from reptile scales. But this is precisely what is not happening with Archeopteryx. On the contrary, the feathers of the "praptits" repeat the structure of the feathers of modern birds to microscopic details.

In addition, there are fossil finds of fragments of feathers from Bernstein, the lower part of the Lower Cretaceous (i.e., layers that were deposited immediately above the Upper Jurassic layers). Conservation in Bernstein allows microscopic examination using the full resolution of a light microscope. This shows a complete correspondence between the fine structure of the feathers of the fossil specimen and the feathers of modern birds. Since similar fossil feathers have been found in Australia and Libya, in addition, feather prints are found in Lower Cretaceous shales in Siberia and Mongolia, and bird paw prints are found in the Lower Cretaceous period in Canada, this should mean that already then birds, despite the poor ability to fly attributed to them, were distributed throughout the world.

In Mongolia, paleontologists have discovered, in addition to the mentioned feather impressions (in the same layers), the remains of a bird with a clearly marked sternum keel. This bony ridge, formed on the sternum, serves as a fixation point for the musculature that ensures flight, and is considered as a typical organ for "highly developed" bird species with a well-developed ability to fly. Thus, similar species of birds must have appeared immediately after Archeopteryx. All of the above also applies to finds of flamingo-like birds from the very bottom of the Lower Cretaceous in France. Fossilized penguins are also world famous from the deposits of the Cretaceous period. According to the evolutionary model, these data indicate that in some species of birds, the ability to fly has undergone a reverse development (atrophied) almost immediately after its appearance. (It remains open question how the mutually exclusive selection pressure necessary for this could arise).

The reptile features mentioned in Archeopteryx should help to find the direct "ancestors of primitive birds" in the class of reptiles, or at least help to find groups of reptiles from which these "greatbirds" could originate. At the same time, however, there are big problems, since individual features inherent in Archeopteryx can be found in completely different groups of reptiles, mutually exclusive of each other as the predecessors of the “prapteryx”: the appearance of the teeth of Archeopteryx speaks, for example, in favor of the fact that its direct ancestor is a crocodile (crocodile-like lizards). Archeopteryx has a typical bird trait - a fork, which was formed from the fused bones of the collarbone (but many parrots and toucans have only collarbones, so can this really give reason to consider them more ancient?). Since many amphibians have clavicles, shouldn't a straight line be drawn from amphibians to birds? However, this line should bypass crocodiles, since they do not have a collarbone. In addition, there are significant differences in the structure of the hip girdle. Despite the fact that it is crocodiles that have correspondingly shaped teeth (although some authors dispute this), as well as a similar structure of the auditory apparatus and jaw joint, differences in the structure of other organs outweigh this similarity and practically exclude them from possible contenders for the role of the predecessors of birds. Hardly anyone today believes that Archeopteryx descended from this order of reptiles. The presence of teeth could just serve as proof of its origin from reptiles, but rather this fact indicates that once there were birds that had teeth, but subsequently died out. In all groups of vertebrates, there are species that have teeth and do not have them!

Archeopteryx has amphicoelous vertebrae (concave on both end surfaces). However, this type of vertebrae is not found in either modern or fossil birds. It is typical of ichthyosaurs, which have never been considered as the predecessors of ancient birds. The hip girdle of Archeopteryx has a four-beam structure, similar to the structure of ornithischians (bird lizards), one of two orders of dinosaurs. But this group also does not have clavicles, which makes it difficult to deduce the origin of birds from these reptiles. And although ornithischians have a hip girdle similar to birds, it is hardly possible to deduce the origin of Archeopteryx from them.

The flying abilities of Archeopteryx could be said with certainty only if one had a clear idea of the state of the atmosphere of that time. Perhaps Archeopteryx was "only" a glider, and this was his ecological niche, which no longer exists, as the density of the atmosphere has changed. If the density of the atmosphere used to be higher, then it is likely that the “prappers” could not only be good glider pilots, but also actively fly (despite the absence of a keel on the sternum). Evidence that other atmospheric conditions existed in antiquity are giant forms of flying lizards (wingspan of about 15 m!), birds (Argentarius birds of prey from the North American Miocene, which had a wingspan of about 7.5 m) and insects (for example, dragonflies) . There is every reason to believe that under today's atmospheric conditions, flying lizards with a wingspan of more than 8 meters would hardly be able to actively fly.

Presentation for the lesson “Birds” Compiled by biology teacher Popova Natalya Stepanovna Archeopteryx Passenger Pigeon Class Birds Birds are a class of highly developed warm-blooded vertebrates whose forelimbs have evolved into wings. External structure External structure The body of a bird consists of a head, neck, torso, fore and hind limbs and tail. On the head are the oral cavity and sensory organs. The jaws end with horny covers that form a beak. Internal structure Internal organs birds have a complex structure, as a result of which new level development: - high and constant body temperature, independent of external environment; - a four-chambered heart, in which there is a complete separation of arterial and venous blood; - fusion of many bones, the presence of a tarsus; - the presence of air sacs; - a higher level of development of the central nervous system. 1st group 2nd group Mating games of seagulls geese Mating games of kosach Mating games of Great Grebe warbler Habitat Birds are an ecologically successful group of animals that “captured” the air element from the Arctic to Antarctica, from sea level to high mountains. Protection of birds Recently, the number of many bird species has been declining. This is due to changes in the environment (atmospheric pollution, massive deforestation, the appearance of predators introduced by humans in the habitats of birds, etc.) and hunting. Over the past four centuries, about 90 species of birds have become extinct, many others have been listed in the Red Book. To increase the number of birds and attract them to the cities, favorable conditions are created for their habitat: birdhouses are hung out, winter feeding is carried out. During the breeding season, hunting for many wild birds prohibited. AT last years man thought about the protection of nature. June 5 is recognized as WORLD ENVIRONMENT DAY. But ornithologists alone, with all their desire, cannot cope with the problem of bird protection. Of course, many protection measures can only be carried out by specialists. And how many things are feasible for each of us! Birds are extremely responsive to any help. Remember the main rule: even if you can’t help in any way, it’s always in your power not to interfere, and this is already not so little! It is very important that birds, such beautiful creatures, tireless workers, full of attractive secrets, live happily on our planet! After all, where it is bad for our neighbors on the planet, it is bad for us too. Don't ruin the bird's nest - So happy is the bird in its home! She is calm in the nest even when the storm is angry over the grove. Don't destroy the bird's nest! THANKS FOR YOUR ATTENTION BA%D0%B8+%D0%B F%D1%82%D0%B8%D1%86%D1%8B&h l=ru&biw=1280&bih=824&prmd=imvns&t bm=isch&tbo=u&source=univ&sa=X&ei= YoW2TqzMJ82O4gSfwsngAw&ved=0CCcQ sAQ

The discovery of the first Archeopteryx fossils in 1860 shocked the scientific world. For the first time, a person saw a creature resembling a half-bird, half-reptile.

   Detachment - extinct birds
   Family - firstbirds
   Genus/Species - Archaeopteryx lithophraphica

Basic data:
DIMENSIONS
Length: 35 cm
Weight: around 300-400

BREEDING
Nesting period: most likely throughout the year.
Incubation period: modern birds of the same size incubate the eggs for about 4 weeks.

LIFESTYLE
Habitat: tropical jungle.
Food: possibly insects, mostly beetles and pasterns.
Habits: lived on the ground, possibly in trees, flew poorly or did not fly at all.

CLASSIFICATION
Class: Birds.
Subclass: Lizard-tailed.
Squad: Extinct birds.
Genus/Species: Archeopteryx lithographica.

Archeopteryx lived 150,000,000 years ago. He is the oldest animal, most reminiscent of modern birds. Fossils of this first bird show that its body was covered with feathers, and its long legs were similar to those of a bird.

FOOD

The large jaws of Archeopteryx were sown with numerous sharp teeth. They were not designed to grind plant foods. But Archeopteryx could not have been predators either, since most of the animals of that period were very large and could not be prey for them. The diet of Archeopteryx most likely consisted of insects. In the Mesozoic era, there were many insects that they could eat. Most likely, Archeopteryx knocked down dragonflies with their wings or, with the help of long legs, collected beetles and other insects on the ground.

LIFESTYLE

Archeopteryx had fused clavicles and a body covered with feathers. It is believed that he could, if not fly, then at least plan. It is likely that on his long legs he ran along the ground until the ascending air current picked him up.
The plumage of Archeopteryx was more likely to help maintain the temperature than to fly. Wings could serve as nets for catching insects. It is believed that Archeopteryx could climb trees using claws on its wings. He spent most of his life in the trees.

BREEDING

The body of Archeopteryx was covered with a thick layer of feathers. There is no doubt that Archeopteryx was a warm-blooded animal. Therefore, the researchers suggest that, like modern birds, it incubated eggs, unlike its closest relatives, dinosaurs from the Coelurosauria group, which probably did not.
Archeopteryx most likely laid eggs in its arranged nests, which it placed on rocks and trees to protect them and their chicks from predators. The babies that hatched from dinosaur eggs could take care of themselves right away. They looked like their parents, only smaller. Scientists believe that Archeopteryx chicks, like the offspring of modern birds, were born without plumage. Consequently, in the first weeks of life, they were probably not independent and required parental care. This means that the Archiopteryx must have had some form of parental instinct, including providing food for the chicks.

NATURAL ENEMIES

In a world where many dangerous predatory dinosaur species lived, the Archeopteryx must have had many natural enemies. With the ability to run fast, climb trees and glide, and possibly fly, Archeopteryx were not easy prey. The main enemies of modern small birds were birds of prey, such as hawks and falcons. In the era of Archeopteryx, predators that fly, most likely, did not yet exist. True, pterosaurs lived in the same period - flying pangolins with membrane wings, but they did not fly very well and could not pursue other animals in the air.

LIVING FOSSIL?

Of modern birds, the hoatzins living in the northeast are most similar to Archeopteryx South America. Hoatzin chicks have claws on their wings that are used for climbing trees. The muscles intended for flight are poorly developed, so hoatzins often climb trees.

DO YOU KNOW WHAT...

Some scientists believe that modern birds are the only living descendants of dinosaurs.
The name Archeopteryx in translation from ancient Greek means "ancient wing".
Today, researchers believe that Archeopteryx evolved from small dinosaurs that, clinging to the claws, began to climb trees.
To date, no fossils have been found of birds that lived 30,000,000 years after Archeopteryx.
The remains of Archeopteryx found in Bavaria are so well preserved (these are whole skeletons with feather prints) that at first scientists had doubts about their authenticity.

STRUCTURE OF THE SKELETON OF ARCHEOPTERYX

   Archeopteryx mostly resembles small dinosaurs, but it also has bird-like features. For comparison - the skeleton of a dove.
   Jaws: resemble a bird's beak, but they had sharp teeth.
   The skeleton of Archeopteryx resembles that of small dinosaurs: it has the same long tail and a similar skull structure. However, there is a difference in the structure of the facial bones.
   Clavicles: fused, which is peculiar only to birds. But there is no evidence that Archeopteryx flew.
   Three fingers with claws: on every wing. Archeopteryx, like bats, needed claws to climb trees.
   Typical paws birds with one finger pointing backwards.

- Archeopteryx fossil finds
WHERE AND WHEN LIVED
So far, 6 Archeopteryx fossils have been found. All are in Bavaria. At the time when the Archeopteryx lived, the territory of Germany was part of a continent that looked completely different, and was in the tropics. Based on the geological age determination of the slates in which the fossils were found, it became known that Archeopteryx lived in the Upper Jurassic period, that is, about 150,000,000 years ago.

"The appearance of living organisms" - The disintegration of a single drop into two or more smaller ones. A set of conditions. Increasing droplet size. Absorption of substances from the external environment. Active volcanic activity. Coacervate drops are the precursors of living beings. Sufficiently high surface temperature of the planet. The emergence of reservoirs.

"The Origin of Life" - The Experiments of Louis Pasteur. L. Pasteur boiled various nutrient media in a flask. spontaneous generation of life. Theories of the origin of life. Creationism. However, Pasteur conducted experiments not only to refute the theory of spontaneous generation. The Steady State Theory states that there has always been life on Earth.

"Hypotheses of the origin of life" - Francesco Redi (1626-1697) In 1668, Redi experimented with vessels in which dead snakes were placed, on which fly larvae appeared. Anthony van Leeuwenhoek (1632–1723) examined protozoa under a microscope Conclusion: tiny organisms, or "animalcules", descend from their own kind. Each of the hypotheses has its strengths and weak sides, but none gives an exact answer to the question of the origin of life.

“How life appeared on Earth” - At the third stage, matrix synthesis appears, self-reproduction of nucleic acids in coacervates. In the 17th century, Leeuwenhoek opened the door to the microworld for people. More resistant coacervates with such RNA gave rise to probionts. Topic: Development of ideas about the origin of life. Microorganisms are brought from space along with meteorites, and then evolution.

"Theory of panspermia" - With the help of panspermia, the appearance of life on Earth was also explained. Proof of. The theory of panspermia - life on our planet is brought from outside, from the Universe. Modern evidence for panspermia. Fred Hoyle's suggestion. Hypothesis. As a result, the universe remains on average unchanged. The hypothesis was put forward in the middle of the XIX century.

"Theory of life on Earth" - They are born, and do not appear on their own .. The ancient world. By the 16th century, the theory of spontaneous generation of living organisms had reached its apogee. Middle Ages. Theory of spontaneous generation. Refutation of the theory of spontaneous generation. Creationism. Therefore, "most insects and worms do not spontaneously reproduce." Antiquity. The theory of panspermia.