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Dinosaurs (Latin deinos - scary and saurus - lizard) are extinct animals that make up a numerous superorder of the reptile class that lived on Earth from 225 to 65 million years ago (in the Mesozoic era). The superorder of dinosaurs belongs to the subclass of archosaurs and is divided into the orders of the Saurischia and Ornithischia.
Life on Earth originated a long time ago, species appeared, evolved, someone disappeared without a trace, and someone passed to a new stage. The modern appearance of the planet is not at all similar to the original. Of all the variety of animals that disappeared during the long life of the Earth, people are especially interested in dinosaurs - the huge masters of the planet, mysteriously disappearing millions of years ago.
The first attempts to study the fossil remains of huge creatures were made in the 19th century, since then mankind has learned a lot about these amazing animals, but has received extensive material for inventions and fantasies at its disposal. New characters have been added to the list of fabulous animals. We already know that dinosaurs have inhabited hardly every corner of the planets for tens of millions of years. The smallest of them were about the size of a chicken, and the largest of them weighed tens of tons.
The term "dinosaur" itself was introduced in 1842 by biologist Richard Owen, comes from two Greek words (deinos - terrible and saurus - lizard) and literally means "terrible lizard". The main mystery of these animals is their mysterious disappearance, one of the versions of which we will consider below. Ordinary people satisfy their interest in these animals from fictional or scientific films, while scientists are still attracted by the deserts of Asia, Africa and the mountains of Patagonia, where you can still find ancient dinosaur remains, touch the riddles and, perhaps, discover new secrets ... Every year, the world's museums are filled with the remains and reconstructions of the skeletons of these animals, attracting visitors. Let us and we go on a journey into the world of these animals, opening the curtain of their secrets.
Dinosaurs were empty-headed - in the empty and figurative sense. At first glance, this statement is somewhat ridiculous, however, it is not far from the truth. The fact is that the skulls of these prehistoric reptiles actually contained air cavities, the volume of which significantly exceeded the volume of the brain. This conclusion was reached by scientists at the University of Ohio, who examined dinosaur skulls using computed tomography. The control group also included crocodiles, the closest relatives of dinosaurs, as well as ostriches and humans. Experiments have shown that air cavities played, firstly, the role of climate control, and secondly, they acted as shock absorbers, keeping the brain from being hit during numerous skirmishes. For dinosaurs with a weak neck, it was much easier to control such a head, since it weighed a little. It turns out these airbags played a role in communication. The configurations of the cavities served as resonators, with their help dinosaurs controlled their voices. Scientists have found that these animals could recognize each other by the smallest nuances of the sounds they make.
The other part of the myth is only speculation, a consequence of man's disdainful attitude towards animals in general. Although the American paleontologist Otniel Marsh, who first studied the skeleton of a dinosaur, said that these animals were stupid and slow. And, indeed, the smallest brain, the size of a walnut, was in armored and spiny dinosaurs, which grazed peacefully, being reliably protected.
The situation is different for predators. The fact is that claws and teeth by themselves will not bring prey to the owners, they must be skillfully used. Predators just need to actively move, constantly tracking and catching up with prey, the brain is constantly busy calculating the possible trajectories of the prey. High intelligence also implied a larger skull. The fossil remains show that the skull of predatory animals significantly exceeded the skull of sauropods - giant dinosaurs with a long neck that ate plant food.
The absolute record for brain volume belongs to Stenychoaurus, the volume of "gray matter" of which was 6 times greater than that of modern reptiles of the same size! The ratio of brain size to body size is comparable to that of chimpanzees. These animals were even distinguished by large eyes, scientists suggest they have binocular vision, like humans and birds. That is, with this type of vision, the brain receives not two different images from the eyes, but one whole, obtained from the area of intersection of images. This improved the hunter's movement accuracy, allowing him to hunt more efficiently. Stenichosaurs, like humans, had a highly developed cerebellum and medulla oblongata, they walked on two hind legs and generally had a humanoid appearance. These animals could analyze events, develop a strategy for joint hunting.
Surprisingly, in most animals with long tails, the spinal cord in the pelvic regions significantly exceeded the brain in volume. Many scientists believe that the pelvic brain controlled the back of the body and tail. As you can see, among the dinosaurs there were species at least not inferior to most of modern animals. Some scientists generally have a theory according to which dinosaurs, having evolved and built their civilization, flew into space to conquer other planets, because they had time for this - millions of years. It would be an erect creature about 135 cm in height, arms and legs would have three fingers, and the body would be covered with dense scales. The eye sockets would occupy about a quarter of the face, and the pupils would be slit-like.
Dinosaurs spent most of their lives in a semi-aquatic environment. But in this case, any attempt to go ashore or enter the water will be doomed to failure - a heavy body will simply get bogged down in the silt. Therefore, all giant dinosaurs (both brontosaurs and sauropods) predominantly led a terrestrial lifestyle. Even nature has taken care of the convenience of the existence of these animals on land. The bones of dinosaurs had cavities filled with air, so the skeleton was as if pneumatized.
In terms of strength, such a structure was not much inferior to a structure made of solid bone tissue, but at the same time, body weight in relation to size was 30-40% less than that of mammals. Hence, there is a direct benefit - animals could move faster and had less need for food. It only seems that dinosaurs were awkward, slow creatures. Many of them had complex behavior, they knew how to take care of their offspring.
However, the aquatic environment was not alien to dinosaurs. So, at the bottom of one dry lake, the paw prints of a therapod were found, which possibly indicate that the animal swam, turning over with its paws, like modern waterfowl. Although there is a version that this dinosaur, due to the insufficient depth of the reservoir, simply clung to the bottom with its paws to resist the current. One thing is for sure - the predators of that time could pursue their prey not only on land, but also in water, although this behavior was not typical of them.
Dinosaurs had smooth or scaly skin. Surprisingly, many of the dinosaurs were covered in feathers. Tufts of feathers were unevenly distributed on the body of the predators. The fact is that feathers are derived from reptile scales, therefore, although their presence may seem unusual, it is quite reasonable from the point of view of evolution. Scientists speculated that feathers performed functions similar to those of birds. They helped animals to maneuver, for animals living in temperate climates, they played a thermal insulation role. And it's no secret that birds evolved from dinosaurs. By the way, feathers may not be the invention of birds and dinosaurs at all. Among the animals that lived more than 200 million years ago, chewing lice are known. Whose fluff or feathers did they eat? After all, then there were definitely no birds yet.
Dinosaurs are mentioned in the Bible. Naturally, the word dinosaur itself is not mentioned in the sacred book, since this concept appeared only in the 19th century, but it contains descriptions of living things very similar to those whose remains are found by archaeologists. At the same time, mythical animals do not look like anyone other than dinosaurs! So, in the book of Job it is mentioned: "Here is the hippopotamus, whom I created, like you; he eats grass like an ox; behold, his strength is in his loins and his strength is in the muscles of his belly; it turns its tail like a cedar; its veins his thighs are intertwined; his legs are like copper pipes; his bones are like iron bars. " When referring to such creatures, the Bible uses the words tannin and hippopotamus. The word "tannin" includes giant, dragon-like sea creatures such as octopuses, squids, and almost extinct marine reptiles. "Hippopotamus" means a royal giant animal.
Bible students come to the conclusion that they are talking about animals that existed a long time ago, since the description does not fit the description of, say, elephants, whose tail does not look like a cedar. The description of, say, legs, size, bones is very reminiscent of just giant dinosaurs. It is interesting that dinosaurs are mentioned in the epic of the Indians, in Babylon, ancient Rome, among the Sumerians and Australians. In the 18th century Anglo-Saxon poem "Beowulf", the hero in 515 fights his enemy Grendel. By its vivid description, it is easily recognizable as none other than ... tyrannosaurus! Amazing is the way Beowulf killed the villain - he tore off Grendel's underdeveloped forelimb. Interestingly, the same way of fighting the monster was depicted on the ancient Babylonian seal. This method will cause the animal to die from blood loss due to high blood pressure. How dinosaurs got into the epics of peoples of different countries and eras remains a mystery.
Dinosaurs died out due to the fall of a giant meteorite. The end of the dinosaur era comes at the end of the Cretaceous period - 65 million years ago. There are many theories trying to explain their disappearance, but none of them gives a clear answer to the "great extinction" that occurred. During this natural disaster, not only dinosaurs died out, but also many marine reptiles, as well as flying dinosaurs, mollusks, and algae. In total, 47% of the genera of marine animals and 18% of the families of animals living on land died. Theories replaced each other - these are floods, and diseases, hunger and cold, the fall of large celestial bodies to the Earth.
The last of these theories is currently the most popular. According to her, after the fall of a large meteorite, a huge cloud of smoke, dust and moisture rose, which obscured the Sun, which led to fatal consequences. The temperature on the planet plummeted, literally in moments many species, including dinosaurs, were swept from the face of the Earth.
In support of this theory, astronomers cite calculations according to which asteroids larger than 10 km collide with the Earth on average once every 100 million years, which in order of magnitude may correspond to the date of the "Great Extinction". The version of the meteorite is based on the existence of the Chicxulub crater in Mexico, which is the trail of a meteorite about 10 km in size that fell more than 65 million years ago. Perhaps, after the disappearance of dinosaurs, mammals emerged from their "shadows" and became the dominant species on the planet.
Science says that in a situation of radical changes on the planet, it is the most highly developed creatures that become the most vulnerable. This is what gave rise to the myth of a group of highly developed animals, which by chance were destroyed, swept away from the top of evolution. The mystery of the disappearance of dinosaurs maintains people's interest in that era, books are written about these amazing animals, films are made, video games are created. Although there is research that refutes this reason for the extinction of the dinosaurs. According to research published in 2003 by British scientists, the meteorite fell into Mexico 300 thousand years before the extinction began, so it could not have caused the disaster. It is all the more incomprehensible how dinosaurs died out as a result of a meteorite fall, but birds that are sensitive to environmental changes remained alive.
The version according to which a meteorite or some other catastrophe became only catalysts for a long chain of significant natural changes looks much more logical. The habitat gradually deteriorated, the nights and winters became colder, warm and moisture-loving animals and plants grew more slowly and began to die out gradually. But they began to be replaced by new ones. And such a process lasted for millions of years, when there were no dinosaurs left on the planet at all.
Another interesting version is based on the fact that dinosaurs are classified as reptiles. Such a classification of dinosaurs, hitherto undefined to any class, suggests that, due to the onset of the Ice Age, a special metabolism of reptiles led to a sharp decrease in the number of female births, which led to extinction. There is no single version, which, the more interest in ongoing research!
Dinosaurs were prone to cancer. Scientists found that tumors in dinosaurs were similar to tumors in humans. This proves that oncological diseases have existed for a long time and have not undergone significant changes. Radiologist Bruce Rothschild has scanned more than 10,000 dinosaur vertebrae, examining different types of them. The scientist found that only one group of the studied - hadrosaurs (or duck-billed dinosaurs), suffered from cancer. No other signs of tumors were found in the bones. The problem of tumors in dinosaurs has been raised in the past, but additional research has confirmed that some bone damage thought to be a consequence of cancer is actually just a consequence of a fracture. But why exactly did hadrosaurs have these diseases? Rothschild is inclined to think that this led to the content in their diet of a large number of conifers containing carcinogens. The structure of the bones of hadrosaurs indicates their warm-bloodedness, which also increases the risk of disease. Perhaps these animals lived longer than others, which gave tumors more time to develop. The question of why hadrosaurs have more lesions in the tail region remains open.
Dinosaurs lived on their own. According to Reuters, paleontologists at the British Museum of Natural History have concluded that dinosaurs had social behavior that took shape much earlier than previously thought. Thus, in northeastern China, the remains of several individuals of psittacosaurs were found, which lay next to each other, as if they were in the same group or herd. Moreover, next to the adults, there were also cubs, the smallest of which was about half a meter long, hatched from different parents and from different eggs. The presence of such a "kindergarten" suggests that these dinosaurs, which lived more than 100 million years ago, existed social behavior. The death of the herd was due to a volcanic eruption, which simply covered them with ash. Psittacosaurs had a beak, lived in the territory of today's eastern part of Asia, and were the ancestors of Triceratops and Proceratops, which, incidentally, also had social behavior. In Texas, 20 parallel, paired tracks of a group of animals were found, including young animals. At present, a lot of evidence of herbivorous dinosaur herbivorous life has been accumulated, and similar evidence appears about small predators.
Almost all dinosaurs were slow.The entire era of dinosaurs was characterized by the presence of both carnivorous and herbivorous dinosaurs, which were distinguished by a particularly proportional structure and could quickly move on their hind legs. For example, coelofusis, was one of the fastest dinosaurs. With an increase of 3 meters, it weighed only about 30 kilograms, accelerating, according to some sources, up to 80 km / h. With evolutionary development, dinosaurs did not lose their speed, for example, the ostrich dinosaur that lived much later was no less fast. Gazelle dinosaurs developed speeds up to 45 km / h.
Dinosaurs have lived for several centuries. Scientists usually determine age from tree rings, which show seasonal changes in tissue growth. However, in a constant climate, this method is unacceptable, since the animals grew evenly. Such rings cannot be found on the bones of animals, or on their teeth, or even on plants of that era. Therefore, there is no exact information about the life span of dinosaurs. Scientists suggest that giant dinosaurs could live up to 200-300 years, while small species lived from one to several decades.
Dinosaurs were heat-loving animals. According to sensational studies by Australian paleontologists, footprints of dinosaurs were found at the South Pole, which lived there at a not warm temperature of -30 ° C. On Ross Island in 2004, scientists found fragments of the jaw and leg of a creature that resembled a Tyrannosaurus. In the depths of the mainland, the bones of a herbivore 10 meters long, resembling diplodocus, were found, and in 2006 the remains of a dinosaur more than 3.5 meters tall were found. All of these animals lived over 110 million years ago. Presumably, they possessed a thick layer of subcutaneous fat, which saved them from the cold. Although skeptics argue that this only indicates that at that time there was a tropical climate at the South Pole. Paleontologists believe that temperatures on the mainland at that time ranged from + 20 ° C in summer to -35 ° C in winter, but perhaps some of the animals were already warm-blooded, which could be a serious event in the history of evolution.