There used to be dinosaurs. When and how did dinosaurs appear? Habitat change

They appeared about 180-190 million years ago, and completely about 60-70 million years ago. It is believed that dinosaurs were, therefore, must have descended from creatures similar to themselves that lived before them. Reptiles are separate animals; they are characterized by the following: they can live on water, are warm-blooded, have a peculiar heart, and the body of most of them is covered with scales.

The first reptiles appeared on Earth many years before the emergence of, they were similar to, and could live both on land and in water spaces. Reptile eggs exclusively. The cubs hatched from the eggs had lungs and legs, could breathe air freely and ate various insects. Over the years, the reptiles became stronger and bigger. Some creatures resembled turtles, others - large lizards. They ate, had thick legs, large heads and short tails.

The first dinosaurs were very similar to their ancestors - reptiles that walked on their hind legs and were more like lizards. Scientists believe that the first dinosaurs were relatively small, the size of a turkey, and walked on their hind legs. Some types of dinosaurs remained small, while others grew long and heavy. Some of them reached a height of 2-3 meters, there were even several six-meter dinosaurs that weighed several tons. They had small heads, as well as blunt, short teeth that were only suitable for chewing plants. Such creatures lived in swampy and low-lying places.

Then came another period in the life of reptiles. Some types of herbivorous dinosaurs became so huge that they could hardly support themselves on four legs on land. Therefore, they began to spend most of their time in swamps and rivers. The largest type of dinosaur, brontosaurus, reached a height of 24 meters and weighed about 35 tons. These creatures disappeared due to climate change on Earth, which deprived dinosaurs of food and habitat.

In the south of France in the 19th century, paleontologists discovered fossilized eggs. Only those eggs were poorly preserved, so scientists were unable to accurately determine the type of dinosaurs and what size they were.

In the Gobi Desert in 1923, researchers laid a clutch of fossilized eggs of prehistoric lizards. They found that several different species of dinosaurs laid eggs, not just one species. Scientists continued to search for such masonry in the south of France, and for good reason - their search was crowned with success!

Researchers were able to find more than 200 eggs, which were approximately 70 million years old. It is worth noting that they were well preserved, as they were under a fairly thick layer of silt. Dinosaur nests in those distant times were most likely destroyed by floods.

The eggs belonged to 10 different species of dinosaurs. They were of different shapes and different sizes. Some were very large and round: their length was 24 cm, their capacity was up to 3.5 liters. IN

Even though I am a girl, the topic of dinosaurs has always been interesting to me. It all started with children's cartoons in which these huge creatures were present. Sometimes they were kind, sometimes evil, however, over the years my interest in these animals only grew. Just recently I had a unique opportunity to go to dinosaur museum in America (my summer holiday). This place was distinguished by its scale, and the guide who conducted the tour told everything in the smallest detail.

Where did dinosaurs come from?

As I know, dinosaurs were not the first inhabitants of our planet, because it originated more than three billion years ago. The first living beings on our planet were, of course, bacteria, mollusks And fish. Initially they all lived in the water. Over time, as a result of evolution, some of the living species began to make their way to land. They had legs and lungs, but still had gills. The first amphibious creatures could not leave the water for a long time, since their scales had to constantly remain wet, but evolution has borne fruit, and the surface of the earth began to be populated by various lizards, which later began to be called by the word known to us "dinosaurs".

If you think that dinosaurs were originally huge, then you are most likely mistaken. According to scientists, initially dinosaurs were small And walked on two legs(many compare them to turkeys). But due to the rule wildlife"survival of the fittest", dinosaurs began increase in size and now, after several thousand years, many of them were already the size of a 25-story building and weighed more than 30 tons.

Dinosaurs: what they really were

Contrary to the popular belief that dinosaurs are extremely vicious and bloodthirsty animals, it turned out that this was not the case (which came as a surprise to me). Our guide said that most dinosaurs were herbivorous reptiles, and, accordingly, they ate only plant foods, moved very slowly and were completely clumsy. No, of course, and carnivorous dinosaurs roamed our land , but there were many of them less than herbivores(and they weren't that big in size). As I understood from the whole excursion, horror stories about huge all-consuming dinosaurs are just fairy tales for little children.

Interesting facts about dinosaurs:

Dinosaurs lived on earth about one hundred million years ago.
Most large dinosaur– seismasaurus(according to scientists, this species lived in the territory).
Dinosaur teeth could reach length up to 20 centimeters.

History of Dinosaurs conceals many mysteries that we, it seems, will not be able to solve. It is known that dinosaurs existed on the planet for more than 160 million years, between the Triassic and Cretaceous periods. From their bones we can guess what they looked like, what they ate, and what the life of these giants was like in general. But scientists even today cannot come to a consensus on one of the most important questions in the history of dinosaurs, namely: how did they die? Perhaps the reason for the extinction of dinosaurs will be better understood if we better study their life history.

Origin of the word "dinosaur"

First, let's talk about what dinosaurs are. Translated from Greek the word "dinosaur"- means "terrible lizard." This is what today they call the reptiles that lived on our planet in the Mesozoic era. The name was proposed by British archaeologist Richard Owen, the founder of paleontology, in the 19th century. He wanted to emphasize in this way the enormous size of the discovered fossils.

As you probably know, all history is conventionally divided into eras. Now is the Cenozoic era, and dinosaurs lived during Mesozoic era, which was divided into the Triassic, Jurassic and Cretaceous periods. The story of dinosaurs has begun during the Triassic period, approximately 225 million years ago.

Dinosaurs were not the first reptiles. Before them, the planet was dominated by more familiar lizards, whose paws were located on the sides. But after global warming occurred about 300 million years ago, new, larger species of reptiles began to emerge. One of them was an archosaur, which is the direct ancestor of all dinosaurs. Presumably, he was one of the first lizards whose paws were located below the body.

Dinosaurs in the Triassic period

The beginning of the Triassic period is characterized by the appearance large quantity new species of reptiles, many of which walked on two hind legs. Archaeological evidence tells us that one of the oldest dinosaur species in history was Staurikosaurus, which lived 230 million years ago in what is now Brazil. In addition to him, then there were cynodonts, orythozchids, aetosaurs and many other species. They turned out to be more adaptable to life than other animal species, and by the end of the Triassic period, giant reptiles began to dominate the entire world.

Dinosaurs of the Jurassic period

Having become the masters of the Earth, dinosaurs settled throughout the planet, populating mountains, swamps, forests and depths of the sea. Soon winged lizards appeared and took over the sky. This time in dinosaur history is characterized by great diversity among dinosaur species. The species of dinosaurs were so different in appearance that it is difficult to believe that they family ties. Among them were giants like Diplodocus, and small lizards, such as Compsognathus.

Dinosaurs in the Cretaceous period

During Cretaceous period Dinosaurs reached their peak as the number of species increased substantially. There are many more herbivores as many new plants appeared on Earth. Naturally, the number of predators has also increased. It was during the Cretaceous period that the famous tyrannosaurus. His fame is well deserved, because he was the largest predatory dinosaur: with a height of up to 12 meters, his weight could be equal to eight tons, that is, he far exceeded the mass of an elephant. In addition to him, other famous species lived at this time, such as Triceratops and Orcheopteryx.

The Mystery of the Death of the Dinosaurs

At the end of the Cretaceous period, approximately 65 million years ago, dinosaurs mysteriously died. Besides them, other lizards and some species became extinct sea creatures. The event that led to this still remains one of the most difficult riddles in the history of dinosaurs. It is not even known whether this happened instantly or whether the extinction lasted hundreds of years. There are many hypotheses, but each of them has its own weak points. According to one of them, the death of dinosaurs was a consequence of a meteorite fall. After this, ash and dust rose into the air, blocking the sun and thus causing the effect of “nuclear winter”. But this hypothesis does not explain the death of marine life, which should have been the last to be affected by the cold. Others say it's because a star exploded nearby, irradiating the Earth with deadly radiation. Still others claim that a cold snap occurred on earth, which killed the dinosaurs. Some even believe that dinosaurs were exterminated by ancient mammals by eating their eggs. In any case, they are no longer there. Perhaps science will someday be able to understand how this happened. After all, we only began to study this issue in the 19th century.

History of dinosaur science

People have repeatedly found dinosaur bones before, but mistook them for something else. For example, the ancient Greeks believed that these were the remains of soldiers who died during the siege of Troy. And with the advent of Christianity, the remains of reptiles were mistaken for the bones of giants who died during the great flood.

At the beginning of the 19th century, Richard Owen laid the foundation for our knowledge of dinosaurs, identifying their main features and identifying them as a separate subphylum of animals. His followers have been accumulating knowledge about these animals for centuries and discovering new varieties. Science does not stand still, so today we know much more about the life of these giants. Nowadays, about a thousand species of these creatures are identified, and work in this area continues.

The footprint of dinosaurs in human culture

Although these majestic animals died a long time ago and no one alive today could see them, these giant reptiles have left a huge mark on our culture. There are a huge number of books, films and other works dedicated to dinosaurs. First, Conan Doyle's The Lost World, which was later adapted into many films. Later there was “Jurassic Park,” based on Crichton’s work, and many other films. Coloring books, toys and cartoons about giant lizards are produced for children.

Even though they died millions of years ago, the history of dinosaurs and their mysterious extinction is still of great concern to the minds of not only scientists, but also ordinary people. Perhaps we are afraid of repeating their fate? After all, like them once, we dominate the Earth. But it is likely that the disappearance of dinosaurs will forever remain one of the many mysteries in the history of our planet that humanity will not be able to solve.

This section of the site is entirely dedicated to these giant animals. History of Dinosaurs, as well as descriptions of various eras and eras are systematized and divided into separate lectures And lecture courses.

The generally accepted story of the origin of life on Earth is outdated. Two scientists, Peter Ward and Joseph Kirschvink, offer a book that brings together all the findings of the latest research. The authors show that many of our previous ideas about the history of the origin of life are incorrect. First, the development of life was not a leisurely, gradual process: cataclysms contributed to the formation of life more than all other forces combined. Secondly, the basis of life is carbon, but what other elements determined its evolution? Third, since Darwin we have thought in terms of the evolution of species. In fact, there has been an evolution of ecosystems - from underwater volcanoes to tropical forests, - which shaped the world as we know it. Drawing on their decades of experience in paleontology, biology, chemistry, and astrobiology, Ward and Kirschvink tell a story of life on Earth that is so fantastic that it is difficult to imagine, and at the same time so familiar that it is impossible to ignore.

Unlike the lungs of mammals, the folded lungs of reptiles and birds are one large alveoli. To increase the surface area for respiratory exchange, such lungs contain many sheet-like folds of tissue directed into the air sac, which is why such lungs are called folded. There are several options for constructing such a lung system. Some have several smaller sections, others have secondary air sacs, which are located separately from the lungs, but are connected to them by tubes. Like the alveolar lungs, in most folded lungs the air enters and exits in one in a common way, however, there were exceptions, and recent discoveries have changed our understanding not only of the nature of early reptiles, but also of their fate during the Permian mass extinction.

Folded lungs are not elastic, and therefore do not automatically compress some time after inhalation. Ventilation also varies from group to group. To draw in air, lizards and snakes use the movement of the ribs, but, as we have already seen, movement prevents the lizard from fully expanding the pulmonary cavity, and therefore these animals cannot breathe while moving.

Various modifications of folded lungs create greater diversity of this type respiratory system than in the case of the alveolar lungs. For example, crocodiles have both folded lungs and a diaphragm, but snakes, lizards and birds do not have this latter organ. However, the diaphragm of crocodiles is not similar to a similar organ of mammals: in crocodiles it consists of connective tissue, attached to the liver, the movements of such a “liver” diaphragm are similar to the operation of a valve or pump, and the pelvic muscles help it. In mammals (and humans), the diaphragm presses on the liver in the same way as in crocodiles, creating a kind of internal pump, but the process of action of this mechanics is noticeably different.

Until recently, the folded lungs of crocodiles and alligators were considered relatively primitive and therefore ineffective. But then we had to revise our understanding of the respiratory capabilities of modern organisms, and also formulate a completely new vision of the evolution of reptiles during the Permian mass extinction and further during the Triassic.

The most ineffective way of breathing is in mammals; in them (we) inhalation and exhalation are carried out through the same channel. The ineffectiveness is due to the collision of gas molecules at the moment the exhalation ends and the inhalation begins. With any acceleration of breathing, a chaotic collision of exhaled air occurs on its way out with the air flow beginning to flow in, and a certain amount of exhaled air - with a higher concentration of CO 2 and a lower concentration of O 2 - again rushes into the lungs. It was long believed that crocodiles experienced the same difficulty. However, in 2010 it was discovered that crocodiles actually use a separate one-way air passage, similar to that of birds and dinosaurs. New evidence also suggests that the ancient Permian and Triassic ancestors of reptiles, which eventually gave rise to modern birds and crocodiles, as well as extinct dinosaurs, had much more efficient respiratory systems than their therapsid contemporaries (the ancestors of mammals). Those ancient ancestors modern reptiles and birds survived the crucible of the Permian extinction thanks to two serious advantages: they were cold-blooded and capable of extracting more oxygen from the air than mammals (than the reptiles that later gave birth to mammals). We mammals have been framed! We've never had much of a chance of winning the fight for survival through extinction events, much less for ecological dominance. Mesozoic mammals were no bigger than rats, and they were truly scared - there were only dinosaurs all around!

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DINOSAURS
When were dinosaur bones first discovered?
Around 1820, fossilized teeth and bones attracted the attention of English and French explorers. large sizes. Studying them, they came to the conclusion that the fossils belong to unusually large lizards - reptiles that lived in prehistoric times. In 1822, the English doctor Parkinson assigned the name Megalosaurus (giant lizard) to one of the finds in the collection of geologist Buckland. In 1924, Bookland began to describe it and gave it a scientific designation. It was then that the dinosaur was first recognized as such and given its name. The second sensational message appeared in 1825. It was made by the English. Doctor Mantel. Three years ago, his wife Mary found a cobblestone in the street rubble containing teeth measuring 4 to 5 cm in size. Such teeth and fossilized bones were also discovered in a nearby quarry. Since the teeth resembled in shape the teeth of iguanas - lizards found in the Center. and South America, Mantel named the newly discovered animal iguanodon (iguana tooth). Following this, dinosaur remains were discovered in England. In Germany in 1837, the bones of a certain dinosaur were also found, which Professor Hermann Meyer called a plateosaurus (plain lizard). At that time, it did not occur to any of the researchers that the discovered animals, known only from fragments, belonged to an independent species of reptiles. London professor Richard Owen was the first to come to this conclusion when more complete skeletons were discovered. In 1841, he proposed that all representatives of this group of reptiles be called dinosaurs - terrible or terribly large lizards. What remains of dinosaurs?
Mostly their bones were preserved. Finding a complete skeleton or skull with teeth is an extremely rare occurrence. Most often, paleontologists (paleontology is the science of animals and plants in the geological past) have to be content with fragments of bones and individual teeth.
The soft parts of the body could not be preserved, but sometimes there are prints of areas of skin on which the smallest details. Findings of fossilized dinosaur eggs or pieces of shells continue to cause a sensation. Unfortunately, one can only guess about their belonging to one or another type of dinosaur. Even if a nest with eggs and a skeleton lying on top are discovered, it cannot be said with complete certainty that they belong to the same species.
Of particular interest are remains of food preserved in the stomach area of the dinosaur, for example, lizard bones between the ribs of the small carnivorous dinosaur Compsognathus. What the dinosaur ate can be determined from its fossilized excrement.
Body traces, especially foot prints, are very valuable, since they can be used to judge the lifestyle, speed of movement and mass of animals.
Why do dinosaurs have such strange names?
Each new species of dinosaur gets its own name. The role of godfather is played by a scientist who studied the find in detail and made a comparison with already known species. A “birth certificate” is a publication in one of the special scientific journals.
The name is always made up of two parts: the name of the family (with a capital letter) and the name of the species (with a lowercase letter). In accordance with scientific tradition, Latin and Latin scripts are used. When choosing a name, they often also resort to Greek words, geographical names and proper names. Most often, the name reflects the characteristic properties of a given type of dinosaur or its remains found. Stegosaurus armatus (stegosaurus armatus, an armed lizard with plates on its back) - the name is given by the plates and spines characteristic of this dinosaur. Ceratosaurus nasicornis (horned nasal horn dinosaur) - This dinosaur has a large horn on its nose. Diplodocus longus (long double beam) is an elongated dinosaur whose distinguishing feature is the presence of double processes on most of the caudal vertebral bones.
Often the name reflects the location of the find, for example in the name Mamenchisaurus hochianensis (Mamenchisaurus hechuanensis). Mamenchi and Hechuan - discovery site and locality in China. Lesothosaurus (lesothosaurus) is found in Lesotho, Africa, and Albertosaurus (albertosaurus) is found in Alberta, Canada.
Personal names are used in titles to honor the merits of outstanding scientists. English names Dinosaur researchers Mantel and Buckland included the names Megalosaurus bucklandi and Iguanodon mantelli. The name of the American paleontologist who discovered previously unknown lizards, Othniel Charles Marsh, is imprinted in the name of the small gazelle dinosaur Othniel, and the surname of the German lizard researcher Janensch is the name of the giant dinosaur Janenschia. Janensch himself immortalized the name of the director of the Berlin Museum of Natural History, Brank, by giving the largest giant dinosaur the name Brachiosaurus brancai (brachiosaurus brancai) - Brank's long-armed lizard. The full two-part name is used mainly in scientific works. In other cases, they are usually limited to the species name. Of the translated Latin names, only a few came into use, for example, armored lizard instead of panoplosaurus. When translated literally from Latin, names often turn out to be unreadable. Therefore, they usually prefer to use original names- many of them, such as dinosaur, brontosaurus or diplodocus, have already become familiar.
Where were dinosaurs found?

Australia

Who are called dinosaurs?
Dinosaurs are just one group of lizards or reptiles that lived in the Mesozoic - the era of average life on Earth. At the same time, other groups of reptiles lived with them, for example, flying and crocodile-like lizards, snake-necked and flat-toothed, fish-like and scaly lizards, as well as reptile-like mammals. The range of differences between dinosaurs was so great that family ties between them are very difficult to establish. They could be the size of a cat or chicken, or they could reach the size of huge whales. Some of them walked on all fours, while others ran on their hind legs.
Among them were dexterous hunters and bloodthirsty predators, but there were also harmless herbivores. But one most important feature, common to all their species, immediately catches the eye: they were all terrestrial animals! Their limbs were located at the bottom of the body, and not on the sides, like most reptiles. Therefore, dinosaurs can also be called running lizards.

Family tree of reptiles and their descendants

Where did dinosaurs come from?
The first terrestrial vertebrates - ancient reptiles or ancient lizards - appeared over 300 mil. years ago. Unlike amphibians, they laid eggs not in water, but on land. The hard shell protected the large egg with a large yolk from drying out. What hatched from the egg was no longer a larva, but a fully formed animal.
These first lizard-sized land animals were the ancestors of all reptiles. Very soon, specific groups of animals appeared among them, adapted to various biological environmental conditions: predatory and herbivorous, slow crawling and fast running, forest and swamp.
At least six different groups of lizards and lizards can be distinguished. One of them includes crocodile-like thecodonts (root tooth lizards) ranging from one to two meters in length. Being predators, they hunted insects, frogs and small lizards, and some of them learned to take an upright position and run quickly on their hind legs. New way movement gave them a great advantage over other groups of lizards, which, like their ancient predecessors, moved on four legs located on the sides. These animals, the fastest among the thecodonts, are considered the ancestors of dinosaurs.

Lizard Euparkeria (root tooth)

How many species do we know?
To date, over 10,000 dinosaur remains have been found: individual bones and entire skeletons, skulls and teeth, eggs and excrement, fossilized footprints and other imprints. All the information about dinosaurs that scientists now have was obtained by studying these remains.
Over the 150-year history of studying fossils, paleontologists have been able to identify and describe over 500 different species of dinosaurs. Information about new discoveries is constantly being received. But it also happens that someone finds fossils and presents them as a new species, but then it turns out that they belong to an already known species, and the new name has to be abandoned. It also happens that a male and a female or a young and an adult animal of the same species are mistaken for different species.
Some of the 500 known species They are so closely related to each other that they are united into one family. Thus, nine species of horned dinosaurs from North America and North and East Africa They belong to the family of brachiosaurs (long-armed lizards). Giant dinosaurs form over forty families.
The most numerous groups include carnivorous dinosaurs, numbering over 150 families, and bird-footed dinosaurs running on two limbs, forming 65 families.
The smallest group in terms of the number of species is apparently the group of spiny dinosaurs, where only eleven families are known so far.
When did the first dinosaurs appear?

Flora during the Triassic period

The era of dinosaurs began in the mid-Triassic, 230 million years ago. At that time, the modern continents were shifted and formed a single whole. The climate was hot and dry, and therefore vast areas of land resembled a desert. Ferns and horsetails grew in the damp lowlands in river valleys and along the ocean coasts, and tree ferns, conifers and ginkgo trees grew in the forests. Animal world in these regions, along with insects and frogs, it was represented by numerous lizards: herbivorous and beak-nosed lizards, turtles and flying lizards, reptiles similar to lizards, crocodiles and mammals.
The first typical representatives of dinosaurs of that time were medium-sized bipedal predators (theropods), such as Chalticosaurus and Coelophysis. Larger and increasingly four-legged herbivorous dinosaurs, such as Plateosaurus, soon appeared. And finally, at the end of the Triassic, the first small bipedal herbivores (ornithopods), in particular the Lesothosaurus, arose.
When did the largest dinosaurs live?

Flora during the Jurassic period

The Jurassic period began ca. 190 million years ago and ended 135 million years ago. Then huge predatory dinosaurs appeared, such as Allosaurus, and their giant herbivorous relatives, such as Apatosaurus. The first birds and flying lizards took to the air, and marine reptiles swam in the seas. Were abundant and widespread conifers and cycads. In the list below, the names of dinosaurs are given without specifying the group to which the genus belongs. 1 - Apatosaurus; 2 - Archeopteryx (primitive bird); 3 - Allosaurus; 4 - Camptosaurus; 5 - Neocalamites (primitive plants); 6 - Ichthyosaurs (marine reptiles); 7 - Stegosaurus; 8 - Plesiosaurus (marine reptile); 9 - Rhamphorhynchus (flying lizard); 10 - Pterodactylus (flying lizard); 11 - Williamsonia (bennettite); 12 - Araucaria (coniferous); 13 - Dilophosaurus; 14 - Cycadeoidea (bennettite); 15 - Ornitholestes; 16 - Compsognathus; 17 - Matonia (fern).
During the Jurassic period, 210-145 million years ago, the continents gradually moved apart, and shallow seas formed between them. The climate became humid and warm, and vast areas were covered with lush vegetation, especially diverse forests. Favorable environmental conditions contributed to the unprecedented flourishing of the world of dinosaurs: numerous new species arose that spread throughout the Earth. Of the living creatures on land, dinosaurs now dominated everywhere, and not other lizards.
At the same time, the evolution of numerous species of giant herbivorous dinosaurs took place. Huge land animals appeared, the largest ever to exist on Earth. Brachiosaurus, Apatosaurus, Diplodocus, Super-, Ultra- and Seismosaurus all lived during the Late Jurassic period. Small gazelles and larger beaked dinosaurs led a group lifestyle. Then came the amazing spiny dinosaurs. Along with smaller, nimble predatory dinosaurs such as Compsognathus and Archeopteryx, giants lived at this time - Allosaurus and Ceratosaurus, which, thanks to their powerful jaws, could cope with large herbivorous animals.
When did the last dinosaurs live?

Flora at the beginning of the Cretaceous period

During the Cretaceous period, 145-65 million years ago, the continents moved apart more and more, the seas between them became wider and deeper, and the climate became a little cooler. This led to the emergence of regions with rich flora, in which new changes took place. Flowering plants appeared, including broadleaf trees, such as magnolia and plane trees. They adapted better to new things climatic conditions and in the end they conquered the whole earth.
Dinosaurs also underwent various changes. Predatory dinosaurs became less and less common; only a few species were able to survive and continue their development. Spiny dinosaurs went completely extinct. They were replaced by armored ones, and then by horned ones. Along with the beaked one appeared large number duck-billed dinosaurs.
Thanks to such richness and diversity of animals, giant predators like the Tyrannosaurus rex had no shortage of food. There were many smaller predatory dinosaurs with different specializations. Some of them were helped to hunt by impressive claws on the front and hind limbs, others, similar to ostriches, had developed forelimbs with which they grabbed small animals, others had no teeth and feasted on eggs, destroying nests.
However, serious changes that took place on earth at the end of the Cretaceous period led to the gradual extinction of all types of dinosaurs.
What are distinctive features giant dinosaurs?
Giant dinosaurs were the largest animals on Earth throughout history.
history. They were 10-20 times heavier than an elephant, the largest of them.
existing land animals. Only blue whale by weight and length
comparable to these extinct giants. With such a huge body weight for
to move on land they needed four legs and very massive
bones. Their limbs, especially the front ones, had a stocky shape, and all
five toes were brought together to form a stable foot. This reminds
an elephant's foot, for which they were nicknamed "elephant's foot" dinosaurs. Their scientific
sauropod name. That is, “lizard foot” dinosaurs.
Another distinguishing feature, one of a kind, was the very
long neck. It was only half the length of the entire animal and
resembled the boom of a crane, capable of rising high and extending far into
side. And the bone structure, for all its strength, was extraordinary
easy.
How are giant dinosaurs different from each other?

Brachiosaurus (long-armed lizard), the largest giant weighing more than 80
tons, could not be confused with anyone. It had extended front
limbs. Therefore, his back formed a smooth descending line,
turning into the tail. The head with powerful teeth sat on a long neck on
height from 12 to 16 meters. The ultrasaurus was similar to him. True, he
known only from isolated bones and may have been even larger. U
All other dinosaur species had significantly shorter forelimbs.
Compared to Brachiosaurus, Camarasaurus (a rock lizard) had a neck
in short, and the body, head and teeth were just as powerful and strong. More
Dicraeosaurus (a curved lizard) looked proportional, and also had
short neck.
Most other dinosaur species had long necks. The greatest, almost
they reached nine meters in length in Mamenchisaurus (the lizard from Mamenchi) and
Barosaurus (heavy lizard). Owner of the longest tail (15 meters)
there was diplodocus (double beam). Thanks to this and its total length (27
meters) he was superior to all other dinosaurs known by complete
skeletons. With a modest weight - only 10 tons! - he also had the most “elegant”
appearance Supersaurus and Seismosaurus (seismic lizard), from which so far have been found
just some bones apparently, were similar to diplodocus, but in length
reached 30 and 40 meters.
What did giant dinosaurs eat?
So far, no remains of stomach or mouth contents have been found.
such dinosaurs. One can only speculate what kind of plants they are
preferred to eat. During the Late Jurassic period, when most people lived
giant dinosaurs, the plant world was presented first
araucaria, as well as ferns, cycads, ginkgo and
coniferous trees.
Taking into account parameters such as neck length, body size and especially jaw size
and teeth, one can get an idea of how these giants ate.
For example, large long-legged and long-necked species such as Brachiosaurus,
was accessible except for trees. Lighter ones, like diplodocus, could even
stand on your hind legs. But their thin pin-shaped teeth were
suitable only for eating ferns and stripping leaves from branches, while
while Kamatosaurus could bite and grind with its powerful teeth
whole shrubs and tree cores.
The teeth of giant dinosaurs were not adapted for chewing food.
So that their muscular stomach can grind pieces of plants, they
They swallowed stones the size of plums and even apples.
Previously, it was assumed that massive animals were constantly in the water and
fed on aquatic and underwater vegetation. It was believed that the dental apparatus
brachiosaurus, diplodocus and other dinosaurs served as gills,
holding food in the mouth and allowing water to flow out. The argument in favor of this
served as the location of the nasal openings of the highest point of the head: gigantic
dinosaurs could, like crocodiles or hippos, lie in water and breathe,
without raising his head. Only occasionally did they go onto land, mainly for
egg laying However, today there is no doubt that these dinosaurs could
They ran well and obtained their food mainly on land.
One can only wonder how, with such a small head and primitive
the structure of the jaws and teeth they managed to provide for their huge body
sufficient food. Apparently the animals spend most of the day
I had to chew.
Enemies of giant dinosaurs.

Judging by the footprints, some species of giant dinosaurs led a herd lifestyle. This provided protection primarily for young animals, since at this time large animals had already appeared, for example carnosaurs: Allosaurus, Ceratosaurus and Megalosaurus. The giant lizards could defend themselves against them only with their long tail, with which they delivered powerful blows, using it as a whip. This is confirmed by fossilized bones, on which there are often traces of healed wounds, most likely received from similar blows. It was dangerous for a predatory dinosaur to fall within the range of such a tail.
Which dinosaur was the largest predator?
Among the first dinosaur finds in England was a fragment of a lower jaw with several teeth. Apparently, it belonged to a huge predatory lizard, which was later dubbed the Megalosaurus (giant lizard). Since no other parts of the body could be found, it was impossible to get an accurate idea of the body shape and size of the animal. It was believed that the lizard walked on four legs. Over the years, many other fossilized remains have been excavated, but a complete skeleton has never been discovered. Only after making a comparison with other predatory dinosaurs (carnosaurs), the researchers came to the conclusion that Megalosaurus also ran on its hind legs, its length reached 9 meters and it weighed a ton.
It was possible to reconstruct the Allosaurus (another lizard) with greater accuracy. Over 60 of his skeletons of various sizes have been found in America. The largest allosaurs reached a length of 11-12 meters and weighed from 1 to 2 tons. Their prey, of course, included giant herbivorous dinosaurs, which is confirmed by the found piece of an Apatosaurus tail with deep bite marks and knocked out Allosaurus teeth.

Tyrannosaurs attacking a herd of Triceratops

Even larger, in all likelihood, were two species that lived 80 million years later in the Cretaceous period, namely: TYRANNOSAURUS (tyrant lizard) from North America and TARBOSAURUS (terrifying lizard) from Mongolia. Although the skeletons are not completely preserved (most often the tail is missing), it is assumed that their length reached 14-15 meters, height 6 meters, and body weight reached 5-6 tons. The heads were also impressive: the Tarbosaurus skull was 1.45 meters long, and the largest Tyrannosaurus skull was 1.37 meters long. The dagger-shaped teeth, protruding 15 cm, were so powerful that they could hold an actively resisting animal. But it is still unknown whether these giants could really pursue prey or were too massive for that. Perhaps they ate carrion or the remains of the prey of smaller predators, which they had no trouble driving away. The dinosaur's forelimbs were surprisingly short and weak, with only two fingers. And a huge finger with a claw 80 cm long was discovered in a Tercinosaurus (sickle-shaped lizard). But whether this finger was the only one and what size the entire animal reached is unknown.
The 12-meter SPINOSAUROUS (spiny lizard) also had an impressive appearance. Along his back, the skin was stretched in the form of a sail 1.8 meters high. Perhaps this served him to scare away rivals and competitors, or perhaps it served as a heat exchanger between the body and the environment.
How did small carnivorous dinosaurs hunt?

Comparison of skeletons

Along with the giant predators, a type of small predatory dinosaur of lighter proportions also appeared - a lizard with hollow bones, or CELUROSAUROUS. These dinosaurs also walked on long hind legs, but ran twice as fast
faster at a speed of 30-40 km/h. At the same time, their body and tail formed a horizontal line, and the neck was held vertically in an S-shaped position. The head was more proportionate to the entire figure, and the jaws were strewn with many narrow teeth. The forelimbs and hands were half as long as the hind limbs. Their sharp, tenacious claws were ideal for grabbing prey. Coelurosaurs hunted small animals, insects and lizards, and sometimes, perhaps, even young animals of their own species. Apparently, they also got some from the prey of large carnosaurs. Already in the Triassic there were many species of these small predatory dinosaurs, for example, the Galticosaurus (an agile lizard) 5 meters long, found in southern Germany and Thuringia.
Later, in the Jurassic period, even more slender long-armed and long-tailed animals appeared. Most often, the back half of their tail was rigid, like a fixed balancer. A nimble and evasive ORNITHOLEST (bird hunter) found in the North. America, reached a length of 2 meters. Compsognathus (elegant jaw) is considered the smallest species - it was the size of a chicken.
Does the ancient bird belong to small predatory dinosaurs?

In 1860, a sensation occurred: in southern Germany, an imprint of a typical bird feather was found in a layer of Jurassic sandstone. Did birds really live at the same time as the giant and the smallest dinosaurs in the Mesozoic era? After all, scientists of that time believed that birds appeared only at the end of the era of dinosaurs. Almost immediately, two complete skeletons were discovered with clear imprints of all plumage, including the characteristic feathered wings. The asymmetrical shape of the individual feathers and their arrangement on the wing were exactly the same as those of modern birds, which undoubtedly indicated that the fossil bird Archeopteryx (ancient wing) was capable of flight. True, the skeleton itself was completely different from that of a bird. It has a long tail, like a dinosaur's, but lacks the short tail of a bird. There are real teeth in the jaws, but no toothless bird beak. There are three free-standing fingers with claws protruding from the front of the wings. There are ribs on the neck and in the abdominal region, separate pelvic bones - everything is like a small predatory dinosaur. However, there is no powerful sternum, no rigid elements of the dorsal spine, no large pelvis, like in birds! Only individual bones and joints resemble those of a bird in shape.
If there were no feathers, then, based on the structure of the bones, the found skeleton would have been classified as a small carnivorous dinosaur. This, however, is what happened with two other finds of this ancient bird, where the imprints of the plumage were poorly distinguishable. For many years they were kept in a collection of dinosaur materials until it was determined that they were specimens of Archeopteryx. Is it really so existing classification turned out to be wrong? Perhaps they were too hasty in classifying this species as birds? Wouldn't it be better to place the ancient bird between these two groups?
Indeed, the ancient bird occupies an intermediate position in the evolutionary transformation of a hollow-bone dinosaur (coelurosaur) into a common bird. In the process of this development there were no big leaps or steps that would allow us to say: up to this point these were indisputably lizards, reptiles, and then - just as indisputably birds. It is also necessary to take into account that changes in individual parts of the body do not occur simultaneously: one part undergoes changes earlier, and the other later. This can also be seen on ancient bird: feathers and wings are clearly avian features, but teeth and tail, on the contrary, unite it with reptiles. In the course of evolutionary changes, there are no sharp boundaries between the categories "coelurosaur" and "bird". The distinctions were made by man out of a desire to “put things in order” and create a harmonious classification of animals.
150 million years ago, ancient birds were of little concern about whether they were predatory dinosaurs or birds and how they should behave. By flapping their wings vigorously, they could take off and fly a short distance, although in flight they may have mostly just been gliding. Their prey were insects and small lizards.
Why do bird lizards have such big eyes?
The eyes and brain of a two-meter bird-lizard (saurornithoid) were unusual
large, almost like an eagle and an owl. Directed forward, such eyes
allowed him to track prey, accurately determining its location, apparently even at night. Quickly and deftly he discovered and caught
nocturnal mouse-like mammals. If the victim managed to hide, he
reached her with his heavily extended forelimbs even from
dense thickets or cracks in stones and rocks. For such sophisticated
In order to hunt, bird lizards also needed a special brain. He was there at six
times more than that of a modern crocodile.
Some researchers suggest that avian lizards and related species
they looked like birds: it is possible that their body was covered with feathers.
What do we know about ostrich dinosaurs?

With the exception of the long forelimbs and tail, slim figures these long-legged predators were very reminiscent of an ostrich or emu. Researchers reflected this similarity in the names of these dinosaurs: ornithomimus, STRUTHIOMIMUS, DROMICEOMIMUS, and GALLIMIMUS, which means “bird-like,” “ostrich-like,” “emu-like,” and “chicken-like.” Like large running birds, they could move quickly, faster than any other dinosaur - perhaps at speeds in excess of 50 km/h. They had no teeth, but apparently had a horny beak. However, we do not know whether they ate like birds. Did you eat insects and lizards, crabs and snails, or dig up the egg nests of other lizards with your forelimbs? Or maybe they were generally herbivores and plucked leaves and branches, fruits and seeds? How did they grab food - with their forelimbs or beaks?
This and much more remains unsolved. Did they lead a herd lifestyle? Did you raise your offspring? Did they lay eggs or were they viviparous? The large pelvic cavity makes the latter assumption quite likely, but this is not a sufficient argument.
How big were the birdlegs?
All species of the second main group of dinosaurs - ornithischians (ornithischians) - were herbivores. But even among them, already in the Triassic, the first species of small animals were known that moved easily and quickly on two legs. Outwardly, they were similar to small predatory dinosaurs, but differed significantly from them in individual elements of their body structure.
Thus, the structure of the bones of the hind limbs was very similar to birds, so they were called bird-footed dinosaurs (ornithopods). Of course, they had the jaws of a herbivore, with tightly packed, faceted teeth, which they used to bite and chew leaves and stems. There were no teeth in the front part of the muzzle, and the jaw bones were covered by a horny beak. Subsequently, among the bird-footed dinosaurs, giants of twelve meters in length and weighing up to five tons appeared. However, the first types were small and light, only one or two meters long. These include LESOTOSAUROUS (a lizard from Lesotho, in South Africa). It had long hind limbs with four toes. There were five short fingers on the front ones, which served as support, as well as for cleaning and searching for food. But most often the forestosaurus tore off leaves, branches and buds with its beak. Before swallowing, he bit them into pieces and chewed them thoroughly. When meeting with a predatory dinosaur, he fled for his life.
Soon new, larger species appeared. A notable feature of them, especially males, were their elongated fangs, which could hardly protect them from predatory dinosaurs - they were most likely used in the fight against rivals. This group was called heterodontosaurs.
How fast did gazelles run?
These were the fastest runners among dinosaurs. Scientists believe that on their “bird” legs they could reach speeds of up to 45 km/h. Apparently, this type of herbivores could successfully live at any time; its representatives are found throughout almost the entire Mesozoic era. At one time, gazelle dinosaurs ranging from one to four meters in length occupied in nature approximately the same place as is now occupied by medium-sized herbivores - from gazelles and antelopes, goats and deer to kangaroos. Like modern animals, they lived in herds.
They had a convenient horny beak for plucking plants. Thanks to the cheeks and cheek pouches, crushed food did not fall out of the mouth from the side. A typical representative of the gazelle dinosaur family was HYPSYLOPHODON (high-crested tooth). It was medium in size, from one and a half to two and a half meters in length, and lived during the Early Cretaceous era in Europe and North America.
The largest species was DRIOSAUR (oak lizard), over four meters long, and the smallest was Nanosaurus (dwarf lizard), whose length did not exceed one meter.
Which beaked dinosaur is the most famous?
Bird-footed dinosaurs are called beak-nosed dinosaurs, the tip of which is covered with a wide, beak-like horny shield. It was very easy to pluck leaves with such a beak; it sharpened itself and constantly grew. The teeth were arranged in a row close to each other, forming a continuous surface, which made it possible to grind and chew food well.
The most typical species among these dinosaurs, the most famous and most frequently encountered, was the Iguanodon; see IGUANODONTS
Other widespread species include Camptosaurus (the curved lizard), named for its curved femur, and Tenontosaurus (the tendon lizard), which had ossified tendons that were stiff along the vertebral column of the back in all beaked lizards. Ouranosaurus (monitor lizard) had long processes on its dorsal vertebrae. It is not yet known whether they served as a support for his skin sail or for a hump similar to a camel's.
What are distinctive features duck-billed dinosaurs?

Corythosaurus group

Most duck-billed dinosaurs (hadrosaurs), of which more than 20 species are known, are distinguished by unusual bone formations on the head. In all other respects they are very similar to each other. Compared to their ancestors, the beaked dinosaurs, their beaks and teeth underwent further specialization. Over 1,000 small faceted teeth formed so-called batteries, so that food was crushed and chewed with file-like surfaces. The long tongue pushed plant food between these batteries into such a position that they were easy to chew. The outside of the mouth had cheeks and protected pouches.
The shape of the beak varied significantly between species - apparently, this depended on the different foods that one or another species preferred. The beak was similar to a duck's only in width, but it was harder, rather short, and there were teeth in the back of the jaw. In addition, it was not used in water, but for plucking and breaking off plants on land.

Fat-headed dinosaurs

Prenocephalic skull

There are many different assumptions about the purpose of the strange bone formations on the head. It is believed, for example, that they served as a nose, protected against overheating, served as an instrument for making sounds, or were simply identifying mark for animals of their own species. But since in males this growth was large in size and, possibly, had a bright color, and in females it was small or completely absent, it is unlikely that it performed vital functions. important function. He probably played main role when individuals of the same species communicate (for example, when males fight for a female), like horns, inflatable larynx sacs, or colored combs on the heads of modern animals.
All these features indicate that duck-billed dinosaurs were very sociable animals and there was a certain hierarchy in their community or herd. Young animals occupied a special position in it and when the herd moved from place to place, they walked behind adult animals. As excavations have shown, females also laid their nests not alone, but in colonies. And the cubs, having hatched, remained in the nest for a long time under the protection of the female.
What did dinosaur skin look like?

Hard areas and elastic skin folds are clearly visible.

Skin is one of those parts of the body that does not turn into fossils and is not preserved for centuries. However, researchers were still lucky enough to find several of her prints. For example, an anatosaurus (duck lizard) was discovered. He died in sandstorm and was buried under dry sand. The anatosaur's skin was smooth, dry and durable, with small raised areas of thicker, horny skin standing out between its soft folds. Small bone plates were placed under these thickenings in the skin.
The ancestors of dinosaurs and their relatives, crocodiles, already had similar plates. It can be assumed that this type of skin was widespread among dinosaurs. In armored lizards, the bone plates are most developed. Their thickness reached 5 cm; they were located close to each other on top and on the sides of the body, forming a strong but flexible shell. It was covered with a layer of horny skin, creating a pattern similar to a tiled mosaic. On pointed or curved bony plates, horny skin enhanced these shapes, creating thick pointed horns or tubercles.
Apparently, the skin of dinosaurs resembled in its structure the skin of three groups of modern reptiles - turtles, crocodiles and beaked animals. However, it is impossible to say whether it was a scaly covering or skin like a snake.
It is also completely unknown what color the skin of dinosaurs was and what pattern it had. All color images are nothing more than the assumptions of researchers or the figment of the imagination of artists.
Skin print of a giant dinosaur. Hard areas and elastic skin folds are clearly visible.
Did dinosaurs require two brains?

Stegosaurus skeleton

More than a century ago, the American paleontologist Othniel Marsh, who first examined the complete skeleton of a giant dinosaur, stated with amazement: “The very small size of the head and brain suggests that the reptile was a stupid and slow animal...”. This opinion is so ingrained that even in everyday life the word “dinosaur” has become synonymous with antiquity and stupidity. However, in relation to many species of these animals, such an assessment is unfair: just remember the agility and dexterity of small predatory dinosaurs or the sociability of duck-billed lizards.
The carnivorous saurornithoid dinosaur had a fairly large brain, almost the same as that of mammals or birds. Recesses in the brain cavities of the skull indicate that the areas of the brain responsible for vision, smell or complex species movements, such as balancing, tactile and grasping functions, were quite well expressed and reached large sizes.
Judging by the shape of the brain cavity of the skull, good eyesight, duck-billed dinosaurs also had a different sense of hearing and smell. It was these feelings that were especially necessary for herbivorous lizards that do not have a shell in order to promptly recognize the enemy.
The smallest brains compared to body size were found in armored and spiny dinosaurs. The elephant-sized Stegosaurus had a brain only the size of a walnut! Was this really enough? In the femoral region of the spine there was another, larger cavity for the nerve center. Could this thickening of the spinal cord represent a second brain, as some researchers claim? Of course not. It was just an ordinary control center for the nerve pathways of the back of the body and tail. Most vertebrates with long tails the spinal cord has a noticeable thickening in this place. And in stegosaurs, the tail was not just huge, longer than the entire body, but also performed a vital function - it served as a weapon of defense. In order to accurately control all the muscles of the tail during a targeted strike, a sufficiently developed nervous system at the beginning of the tail.
However, the real brain is only the one contained in the skull. And apparently, such a brain was quite enough for the dinosaur, serenely grazing under the protection of its formidable spines, because spiny dinosaurs existed for many millions of years.
How fast did dinosaurs run?

Speed characteristics of various dinosaurs

Throughout the entire era of dinosaurs, among both carnivorous and herbivorous bird-footed dinosaurs, there were species that were distinguished by a particularly proportional structure and moved only on their hind limbs. So, for example, CELOPHIS, who lived in the Triassic, was one of the fastest among the first dinosaurs. He was slender and light: with a three-meter length, he weighed only about 30 kilograms. Some of the last dinosaurs, who lived at the end of the Cretaceous period, 150 million years later than Coelophis, were no less slender and fast, for example the ostrich dinosaur (picture above). But how can one draw any conclusions about the speed of movement of animals that have long since become extinct?
What should we proceed from here? Three circumstances must be taken into account: firstly, the length of the animals' legs - it can be easily determined from the bones found; secondly, body weight - it is calculated approximately; thirdly, the length of the step and the type of walking and running - they can be determined by the structure of the body and the fossilized footprints of dinosaurs. To more clearly imagine the running speed of dinosaurs, you can compare them with the “fast walkers” among modern vertebrates: racing horses and greyhounds, gazelles and cheetahs, hares and kangaroos, ostriches and California running cuckoos. The champions here are the cheetah and some species of gazelles, capable of reaching speeds of up to 100 km/h, that is, medium-sized animals with a body weight of about 50 kilograms. Lighter and more massive animals run slower.
What did dinosaur eggs look like?
Dinosaurs laid eggs. Given that they were reptiles, this was assumed even before their eggs were discovered. It was also clear that in size they could not be larger than the hole in the pelvis of the females through which they had to pass. But what exactly these eggs were, scientists were able to find out only on the basis of the first finds.
For the first time, the fossilized remains of dinosaur eggs were found back in the last century in the south of France, but it was impossible to determine their size or identity from them. The first clutches of eggs were discovered in 1923 in the Gobi Desert. Moreover, these were eggs of not just one, but different types of dinosaurs.
But in the south of France, where they were discovered for the first time, further excavations also turned out to be very fruitful. Several hundred eggs were found here, buried under a layer of sand and silt during a flood some 70 million years ago. Among them, ten were identified various types eggs The largest were round in shape, 24 cm long and with a capacity of three to three and a half liters. One partially preserved nest, one meter wide and 0.70 meters deep, contained 12 such eggs. They may have belonged to the giant dinosaur Hypselosaurus.

found in the Gobi Desert. Dinosaur egg

How did dinosaurs take care of their offspring?
Reports of the most amazing dinosaur nest discoveries began to arrive in 1978 from American state Montana. An entire colony has been preserved here - more than a dozen nests of duck-billed dinosaurs. Each nesting hole reached two meters in width and one in depth. In one of the nests there were only crushed egg shells, in the other there were young animals from half a meter to two meters long. At the time of emergence from an egg about 20 cm long, the young animal could be no longer than 30-35 cm.
This means that the cubs were in the nest for quite a long time (they crushed the shell) under the protection of the mother who fed them. This duck-billed dinosaur was named Maiasaura (mother lizard). The females weighed at least two tons and could barely hatch eggs. Most likely, the plant material used to build the nest, when rotting, released heat sufficient for the development of the embryo in the egg.
There was a nesting site for gazelle dinosaurs nearby, which had apparently been in use for many years. Ten meter-long nests contained 24 oblong eggs. But the hatched baby gazelle dinosaurs did not remain in the nest, but immediately left it and gathered nearby in groups of young animals. Thus, dinosaurs exhibited nestling and brood behavior among young animals that were cared for differently by females.
Did dinosaurs lead a herd life?
Findings of fossilized footprints and massive accumulations of bones provide evidence that some dinosaurs lived in herds. For a professional researcher, footprints can tell a lot about the behavior of animals.
In Texas in the layer rocks 20 pairs of giant dinosaur tracks were found. The tracks ran parallel, only a few of them intersected. They were of different sizes, therefore there were young animals in the herd that walked in the middle. A herd of duck-billed dinosaurs left their footprints on one of the rock slabs discovered in Canada. They walked in wide formation on the soft ground at that time. The young animals appeared to be at the back of the herd, as their tracks overlapped those of the older animals. To date, quite a few arguments have been accumulated in favor of the gregarious lifestyle of herbivorous dinosaurs.
But some species of small predatory dinosaurs also stayed together. This is confirmed by nineteen identical tracks from medium length steps located close to each other on the same site. This means that these animals also hunted in herds. Large, heavy carnivorous dinosaurs have so far only seen single tracks.
How long did dinosaurs live?

Duck-billed dinosaurs: female with babies

The simplest method of determining age by tree rings, which reflect seasonal changes in the rate of tissue growth, does not apply to dinosaurs. At that time conditions environment were the same throughout the year, and the animals could grow evenly. Tree rings did not form on trees or on the teeth or bones of dinosaurs. Therefore, we can only speculate about the age of dinosaurs. Immediately after birth, the animals certainly grew quickly, especially the chicks, which were fed and protected by the female during the first weeks of life. Brood animals were more independent at an early age, but grew more slowly. Once young dinosaurs reached two-thirds the size of an adult animal, they became capable of procreation. Now their growth slowed down, but did not stop until the end of their lives. It is believed that giant dinosaurs required 40 to 50 years to reach sexual maturity, and they could live up to 200 or even 300 years. The life expectancy of small species was, in all likelihood, less - from one to two decades.
When did dinosaurs go extinct?
Usually the answer to this question is short and clear: 65 million years ago at the end of the Cretaceous period, at the end of the Mesozoic era. For 150 million years, constantly changing species of dinosaurs reigned supreme on our planet, and then suddenly disappeared from the face of the Earth in a short period of time. No traces have been found in Tertiary sediments.
True, not all species and groups of dinosaurs even survived to the end of the Cretaceous period. Already 120 million years earlier, in the middle of the era of dinosaurs, for example, the last ancestors of giant dinosaurs disappeared. And spiny dinosaurs died out 60 million years earlier than other groups. But their place was taken by others - thick-headed and horned dinosaurs.
New species constantly appeared, while a significant part of the old ones disappeared. Most dinosaur species only existed for about two to ten million years at most.

Triceratops, extinct 65 million years ago

Why did dinosaurs become extinct?
Ever since dinosaurs were discovered, researchers have always wondered why they disappeared so completely at the end of the Cretaceous period. More than a hundred hypotheses were put forward on this score, but almost all of them turned out to be untenable.
It has often been overlooked that, unlike dinosaurs, other groups of animals - crocodiles, lizards, snakes, turtles, birds and mammals - survived this critical time. Why were they an exception?
On the other hand, at the same time as land dinosaurs, sea lizards, ammonites and small marine animals, as well as land plants, disappeared. This means that they were influenced by the same reasons! Hypotheses about global flood- After all, marine animals also died out, and many land animals were not affected at all. Hypotheses about the extermination of dinosaurs have no basis either. primitive man, which, as has already been proven, appeared only 60 million years later.
Internal reasons associated with the dinosaurs themselves, such as their enormous growth and clumsiness, cannot be considered sufficient, since both the smallest and the fastest dinosaurs became extinct. The assumptions that carnivorous dinosaurs destroyed herbivores and then themselves died of starvation, or that all the dinosaurs were eaten by small mammals, also do not stand up to criticism. But then why didn’t they touch the reptiles that have survived to this day? One of the newest hypotheses puts forward as the main cause a sudden catastrophe that occurred on Earth - a collision with a huge meteorite. According to this hypothesis, it fell to Earth celestial body ten kilometers in diameter. From the impact, such an amount of dust rose up that the sky over the entire Earth darkened for many months. Plants that require sunlight, followed by herbivores, and then predators. A cold snap occurred as the sun's rays no longer reached
earth's surface. Then warming came again, when the upper layers of the air warmed up again. And even if some species managed to survive the catastrophe, they still died as a result of its consequences, which lasted for years and centuries. If this catastrophe, the likelihood of which can be judged by a number of signs, was really so destructive, then the sudden appearance of all dinosaurs is quite understandable. But it is completely incomprehensible how such sensitive representatives of the animal world as birds could survive!
A more convincing and justified point of view is that the extinction of dinosaurs did not occur suddenly, but continued over a fairly long crisis period. Living conditions gradually deteriorated for those animals that were adapted to the previously uniform warm and humid climate, to a rich flora and fauna. Constant movements of continents and seas have led to significant climate changes. As the earth's crust shifted and the ocean floor expanded, more and more shallow areas became more sparsely vegetated land. Warm conditions without any temperature changes gave way to colder nights and harsher winters.
Many dinosaurs were deprived of their usual feeding conditions when food was abundant everywhere. Cold nights and winters adversely affected the breeding of offspring. The babies grew more slowly, certain types of dinosaurs became increasingly rare and gradually began to die out, in some regions earlier, in others later. The crisis period continued on land for at least five million years. There was a process of extinction of dinosaurs and flying lizards. Along with them, entire species of plants and mammals also disappeared, but they were already replaced by new ones.
A meteorite strike or some other sudden catastrophe could only significantly disrupt the living conditions of animals and plants and cause the process of gradual extinction of many of their species, but not destroy them immediately. This point of view provides a more logical explanation for the mysterious disappearance of dinosaurs.