Pictures of dinosaurs with their names. What do we know about dinosaurs? Tyrannosaurs are the most famous dinosaur species

The origin of dinosaurs has been one of the most pressing mysteries and topics of debate in the last century. But even now very little is known about these lizards. What were they like? Can a dinosaur be considered the “king of nature” and the pinnacle food chain of your period?

Answers to these and many other questions have never been found. Even those pieces of information that archaeologists and paleontologists have been able to collect are based rather on the analysis of fossils and theories built around the principles of life of similar organisms.

Many species of dinosaurs are still only superficially studied, and therefore there is no need to talk about a sufficient knowledge base on this issue.

Basic classification of dinosaurs

The differences between dinosaur species are dictated by habitat, food preferences, diet, and even class.

Some names come directly from the names of the discoverers, as well as the territories where the skeleton of a particular lizard was first found.

The type of dinosaur also varied significantly depending on which predator was dominant in the region. So, to

for example, huge diplodocus were perfectly protected from small aggressors, for example, deinocheira, but they didn’t just hunt for the young of this subspecies of herbivores, they literally threatened their population.

In general, dinosaurs can be divided into 4 classes:

• Predators.
• Herbivores.
• Flying.
• Aquatic.

However, some dinosaurs managed to combine several classes in their specificity.

Predators

The class of predators includes several subspecies, which can be conditionally grouped into two categories: large and schooling.

The first class, for example, includes the T-rex, or, more simply, the tyrannosaurus. It was one of the most famous predators of its period, which was about 65 million years ago.

This dinosaur, like its fellows, is characterized by a solitary lifestyle, hunting mainly for large game. With a length of fangs of 15-19 centimeters, it was not a problem for this lizard to bite through even the strong shell of a stegosaurus or fight with a triceratops.

Its name even contains a direct reference to the reputation of the lizard - namely the prefix “ti”, the entomology of which is close to “terror”, which translates as “horror”.

The same kind of dinosaurs also include Allosaurus, Dilaphosaurus, Carnotaurus and Megalosaurus.

The latter species is very characteristic, but the complete skeleton of this lizard has never been found.

School predators They were distinguished by considerable intelligence and hunted mainly young animals of large herbivorous dinosaurs and sick loners.

They could not only coordinate their actions within the pack, they were in contact with

other representatives through sound effects. If the brain of an average stegosaurus reached the size walnut, then in Velociraptor it was already the size of a large orange.

A distinctive feature of this type of dinosaur is the large claw on the first toe of the hind paw, through which hunting took place.

The velociraptor jumped onto the back of its prey, after which it tried to break the spine or inflict wounds leading to blood loss. This type of dinosaur is characterized by hunting in a pack, the type of which is similar to the actions of wolves.

Herbivores

The class “herbivores” has several subspecies. Most often they are called according to the names of several of the most famous representatives (Triceratops, Stegosaurus and Diplodocus).

At one time, the last one mentioned was for the entire period of the existence of lizards. Its length from nose to tip of tail reached 30 meters.

Ultrasaurus was supposed to become the new record holder, but, as in the case of Megalosaurus, a complete skeleton of the lizard was not found. This species is characterized by enormous sizes, even the “smaller” of them, namely Apatosaurus reached a record 22 meters.

The dinosaur called Triceratops was not in danger of a head-on fight. Like the modern rhinoceros, this dinosaur crushed the enemy with its horns, although there were three of them, and the lizard’s neck was covered with a bone “collar”, which also served to regulate heat exchange.

Stegosaurs and brontosaurs preferred defense to attack. Such dinosaurs simply needed to stay on their feet, huddle in a pack and patiently wait out the attack. Their backs are tightly protected by a horny shell.

The stegosaurus also had spikes at the tip of its tail, with which the lizard skillfully defended itself from small aggressors.

One of the heaviest dinosaurs, namely the brontosaurus, had a heavy bone club at the end of its tail, which could easily break the skull of, for example, a velociraptor.

Water

Aquatic dinosaurs The class of predators is almost entirely represented. The largest of them, namely the plesiosaur, according to a number of scientists, may well be the one. The length of its neck reached 11-15 meters.

Mosasaurs and ichthyosaurs have been named as the ancestors of modern dolphins.

The Pliosaurus, also known as Predator X, was the most aggressive. This dinosaur is characterized by attacks, including on its own relatives. It is likely that killer whales are the descendants of the pliosaur. Most of these lizards became extinct after average temperature water began to fall as a result of the advance ice age.

Flying

Some flying dinosaurs later evolved into birds, others remained their own subclass, but they were a serious threat in their environment and deserve mention.

He hunted insects (the size of which reached 2 meters during the period of the lizard’s existence) and he himself was far from small. It was in his skeleton that the remains and traces of feather cover were found, after which the origin of modern birds from this subspecies was proven.

The second subclass, represented by the pterodactyl, had a fur coat and huge leathery wings. Dinosaurs of this species have a diet of fish, fruits and insects.

Each type of dinosaur had its own specifics and characteristics. Such a compressed characteristic is not capable of giving a full assessment of them, but is sufficient for the primary one. At one time, dinosaurs were a huge force, but later they lost the battle to nature and even mammals, losing primacy once and for all.

Can you imagine what dinosaurs looked like when they ruled this earth many years ago? Let me answer this question. Some species of dinosaurs, once the largest creatures on the planet, were as tall as a four-story building and weighed more than the combined weight of a hundred cars.

Interested? There is still a lot known about dinosaurs interesting facts. As you may have guessed, it is these prehistoric reptiles that we will talk about today on the site about animals. We will tell you what groups dinosaurs are divided into, about their evolution, as well as hypotheses about why dinosaurs became extinct.

These giant creatures get their name from the Greek and Latin language. Speaking in simple words, dinosaur means "terrible lizard".

They are usually named after their body features, the location where they were found, or after the person involved in their discovery. The name usually consists of two Greek or Latin words or combinations thereof.

Types of dinosaurs. All dinosaurs were different from each other. Their food preferences were different, they were different sizes, the walking style of some was different from others, there were many more features.

Dinosaur groups

Sauropods- a group of herbivorous dinosaurs, which was distinguished by the most impressive size among the rest - a large body, long tail and a neck, which, like the giraffe, helped to reach tree foliage for food.

Theropods- carnivorous dinosaurs. This group of predators had excellent eyesight, sharp teeth and equally sharp claws, which were very helpful in hunting.

Large herbivorous dinosaurs with huge bony plates along their long spines. It is believed that these spines not only served as a deterrent to predators, visually increasing the size of the dinosaur, but also participated in thermoregulation processes due to the huge number of blood vessels located in them.

Brachiosaurs- huge dinosaurs that lived in herds. Their size can be compared to two double-decker buses stacked on top of each other. Like all sauropods, they had a long neck, which helped them reach succulent foliage from tall trees.

Some dinosaurs preferred to move exclusively on two legs, which is why they were called bipeds, while others walked only on four. But there were species that could move freely on both two and four legs.

Evolution of dinosaurs

Dinosaurs appeared about 230 million years ago; their ancestors are reptiles that inhabited the watery expanses of the Earth. In the process of evolution, terrestrial species of dinosaurs arose. Their appearance was very different from more primitive reptiles. Even now, no one can say for sure why such changes occurred. But one thing is clear - as a result of evolution, the strongest survive. And only a small percentage is due to chance.

The first dinosaurs were not large sizes(about 10-15 feet in length) and had a fragile build. They moved quickly on two legs. Their remains were first discovered back in the last century in Madagascar, off the coast of southern Africa.

Eoraptor is one of the very first dinosaurs, which appeared about 228 million years ago. In size it is not more dog, but, nevertheless, it was a predator that moved quickly on two legs.

Not all prehistoric animals were dinosaurs. In addition to them, there were many other representatives of the fauna.

Dinosaurs inhabited exclusively land. None of them lived in the sea or flew. True, some carnivorous species eventually developed feathers and evolved into birds.

Not all dinosaurs were huge. Among them there were also small specimens. The smallest one was the size of a chicken, which is why it was called Compsognathus.

Birds are the only surviving descendants of dinosaurs. Humans themselves, as most experts suggest, never coexisted with dinosaurs.

The number of teeth in each type of dinosaur was completely different. Some did not have them at all, others had 50-60 thick teeth, shaped like a cone. But hadrosaurs had the most teeth - about 960. An interesting fact is that if an animal’s tooth fell out or broke, a new one always grew in its place.

Life expectancy different types dinosaurs was significantly different. Larger species could live up to 100 years, while larger species small dinosaurs it was significantly shorter.

Why did dinosaurs become extinct?

Extinction is the process of disappearance of entire animal species. This occurs when the death rate exceeds the birth rate and is considered a natural result of evolution. That is, if organisms cannot adapt to the conditions of existence in environment, they disappear.

Dinosaurs became extinct about 65 million years ago as a result of sudden climate changes following the collision of a large asteroid with the Earth. This is the most popular theory explaining the death of dinosaurs.

It is believed that a large asteroid crashed into the Earth at high speed. Its dimensions were about 10 km in diameter. Because of this, a wave of earthquakes occurred, raising clouds of dust, which caused the death of the dinosaurs.

According to another theory, a strong cooling occurred on Earth, and animals, without feathers or fur, could not survive in such climatic conditions.

Today it is believed that only birds have preserved some characteristic features, inherent in the distant past to dinosaurs.

Fossil animal bones have been found on every continent without exception. It is quite possible, it may even be somewhere near you.

About 230 million years ago, the first dinosaurs evolved from a population of archosaurs (Archosauria), which shared the planet with many other reptiles, including the bestial reptiles - therapsids (Therapsida) and pelycosaurs (Pelycosauria). How separate group, dinosaurs have been identified by a set of (mostly obscure) anatomical features, but the main thing that simplifies their identification and distinguishes them from archosaurs is their bipedal or quadrupedal upright posture, as evidenced by the shape and arrangement of the femur and tibia bones. See also: " " and " "

As with all such evolutionary transitions, it is impossible to determine the exact moment when the first dinosaur appeared on Earth. For example, the bipedal archosaur Marasuchus (Marasuchus) was perfect for the role of an early dinosaur, and Saltopus lived with the dinosaurs (S. elginensis) and procompsognathus (P. triassicus) during the transition between these two forms of life.

Newly discovered genus of archosaurs - Asilisaurus (Asilisaurus), can move roots family tree dinosaurs until 240 million years ago. There are also controversial tracks of the first dinosaurs in Europe, dating back 250 million years!

It is important to keep in mind that archosaurs did not “disappear” from the face of the Earth after becoming dinosaurs. They continued to live side by side with their eventual descendants for the remainder of the Triassic period. And just to confuse us completely, around the same time, other populations of archosaurs began to evolve into the first pterosaurs (Pterosauria) and prehistoric crocodiles. For 20 million years, during the Late Triassic, the landscapes of South America were rife with similar-looking archosaurs, pterosaurs, ancient crocodiles and early dinosaurs.

South America - Land of the First Dinosaurs

The earliest dinosaurs lived in the region of the supercontinent Pangea, corresponding to the territory of modern South America. Until recently, the most famous of these creatures were the relatively large Herrerasaurus (about 200 kg) and the medium-sized Staurikosaurus (about 35 kg), which lived about 230 million years ago. But now, some of the attention has shifted to Eoraptor (Eoraptor lunensis), discovered in 1991, a small (about 10 kg) dinosaur.

A recent discovery could revolutionize our understanding of the South American origins of the first dinosaurs. In December 2012, paleontologists announced the discovery of Nyasasaurus (Nyasasaurus), who lived in the Pangea region corresponding to modern-day Tanzania, Africa. Amazing! The fossil remains of this dinosaur are 243 million years old, which is about 10 million years older earlier than the first South American dinosaurs. However, it is possible that Nyasasaurus and its relatives represented a short-lived offshoot of the family tree early dinosaurs, or technically they were archosaurs and not dinosaurs.

These early dinosaurs gave rise to a hardy group of reptiles that quickly (at least in evolutionary terms) spread to other continents. The first dinosaurs quickly migrated to the regions of Pangea corresponding to North America ( a shining example is Coelophysis (Coelophysis), thousands of fossil remains of which were discovered in Phantom Ranch, New Mexico, USA, as well as the recently discovered tawa (Tawa), which are cited as evidence of the South American origin of dinosaurs. Small to medium-sized carnivorous dinosaurs, e.g. , soon made their way to the eastern part North America, and then further to Africa and Eurasia.

Specialization of early dinosaurs

The first dinosaurs coexisted on equal terms with archosaurs, crocodiles and pterosaurs. If you were to travel back in time to the end of the Triassic period, you would never guess that these reptiles were superior to all others. Everything changed with the mysterious Triassic-Jurassic, which wiped out most archosaurs and therapsids. No one knows exactly why dinosaurs survived, perhaps it has something to do with walking upright, or more complex structure lungs.

Back to top Jurassic period, dinosaurs began to diversify the ecological niches left behind by their extinct counterparts. Split between lizards mi (Saurischia) and ornithischians (Ornithischia) dinosaurs occurred at the end of the Triassic period. Most of the earliest dinosaurs were saurischians, such as sauropodomorphs (Sauropodomorpha) that evolved into bipedal herbivorous prosauropods (Prosauropoda) in the Early Jurassic period, as well as larger sauropods (Sauropoda) and titanosaurs (Titanosaurus).

As far as we can tell, ornithischian dinosaurs, including ornithopods, hadrosaurs, ankylosaurs, and ceratopsians, evolved from eocursor (Eocursor)- a genus of small, bipedal dinosaurs from the Late Triassic South Africa. Eocursor most likely descended from an equally small South American dinosaur (possibly Eoraptor), which lived 20 million years earlier ( clear example, how such a huge variety of dinosaurs could have arisen from such a humble progenitor).

List of first dinosaurs

Name (genus or species)	Brief description	Image
	a genus of lizard-hipped dinosaurs related to herrerasaurs (Herrerasaurus).
Coelophysis (Coelophysis)	kind of not large dinosaurs, living in North America.
	genus of small dinosaurs close relative compsognathus (Compsognathus).
Compsognathus (Compsognathus)	a genus of dinosaurs the size of a large chicken that lived in the late Jurassic period.
Demonosaurus (Daemonosaurus)	predatory reptiles from the suborder theropods (Theropoda).
Elaphrosaurus (Elaphrosaurus)	a genus of carnivorous dinosaurs from the late Jurassic period.
Eodromaeus (Eodromaeus murphi)	view of the ancients predatory dinosaurs from South America.
Eoraptor (Eoraptor lunensis)	a species of small dinosaur, one of the first of its kind.
	a genus of early dinosaurs named after Godzilla.
Herrerasaurus (Herrerasaurus)	a genus of the first predatory dinosaurs from the vastness of South America.
Lilienstern	genus of the largest carnivorous dinosaurs of the Triassic period.
Megapnosaurus (Megapnosaurus)	Translated from Greek, the genus name means "big dead lizard."
Pampadromaeus barberenai	an ancient species of herbivorous reptiles and the ancestor of sauropods.
	a genus of one of the earliest dinosaurs in North America.
Procompsognathus (Procompsognathus)	a genus of prehistoric reptiles that may have been related to archosaurs.
Saltopus	as in the previous case, it is not known exactly whether Saltopus belonged to dinosaurs or archosaurs.
Sanhuansaurus (Sanjuansaurus)	a genus of early dinosaurs from South America.
	a genus of carnivorous dinosaurs from the wider England of the Early Jurassic period
	a genus of small reptiles from the suborder of theropods that lived in North America during the Jurassic period.
Staurikosaurus	primitive carnivorous dinosaur of the Late Triassic period.
Tawa (Tawa)	a genus of lizard-hipped carnivorous dinosaurs found in southern North America.
Zupaisaurus (Zupaysaurus)	a representative of early theropods discovered on the territory of modern Argentina.

1. Triceratops (Triceratops horridus)

Triceratops is a herbivorous dinosaur that lived on Earth at the end of Cretaceous period in regions of North America.

Being herbivores, Triceratops fed on shrubs and plants such as ferns, palms and cycads. These herbivorous dinosaurs had beak-like mouths that could mainly only grab food and not bite. Interestingly, these dinosaurs had up to 800 teeth, which served exclusively for grasping vegetation.

An interesting fact is that many of them had horns.

2. Dracorex († Dracorex hogwartsia)

Dracorex was a herbivorous dinosaur that existed during the Late Cretaceous. This dinosaur reached 1.4 meters in height, 6.2 meters in length and weighed about 45 kg. Dracorex had an original long mouth. Numerous spikes and bumps were located on his skull.

It is currently still debated whether this dinosaur is a herbivore or not. Dracorex had extremely sharp teeth with many fangs,

therefore, some scientists classify it as an omnivore.

Its name, Dracorex hogwartsia, is taken from the popular Harry Potter book series by J. K. Rowling. As you understand, this name means “Dragon King of Hogwarts”.

3. Moschops († Moschops capensis)

Moschops is a genus of prehistoric herbivorous mammalian reptile that existed during the Permian period. Most of the remains of Moschops have been excavated in a region called the Karoo in South Africa.

In this habitat, Moschops was the largest herbivore. He had a massive

body (about 5 meters in length), a thick skull and a very short but heavy tail.

As mentioned above, this dinosaur had a herbivorous lifestyle, so its teeth were serrated at the ends - this helped to chew plants.

4. Argentinosaurus († Argentinosaurus huinculensis)

The next herbivorous dinosaur on this list is Argentinosaurus, which may have been the largest and most massive land animal that ever existed. Argentinosaurus led a herbivorous lifestyle, as it fed on plants that grew on our planet during the Jurassic period until the end of the Cretaceous period. He had long neck, allowing easy access to the treetops.

Literally, the name of this dinosaur means “silver lizard.” Argentinosaurus fossils were first excavated in South America in 1988. Unfortunately, very little information is currently known about this dinosaur species.

5. Stegosaurus († Stegosaurus)

Stegosaurus is known to be a genus of herbivorous dinosaurs that primarily inhabited areas of western North America during the Late Jurassic period.

This herbivorous dinosaur is characterized by a toothless beak and small teeth on the inside of its cheeks. It follows that such teeth were not suitable for eating animal flesh. Unlike other herbivorous dinosaurs, which had strong jaws and teeth for grinding plant matter, this dinosaur had jaws that only allowed the teeth to move up and down.

Among dinosaurs, Stegosaurus is known for having a relatively small brain and may even have had the lowest brain-to-body ratio.

This dinosaur, whose name literally means “covered lizard,” is remembered because of the presence of plates that lay along its back in a vertically flattened position. In total, this dinosaur had 17 original spines on its back (called pincers), which were not hard as such, but consisted of soft bone material where many blood vessels ran.

6. Edmontosaurus († Edmontosaurus regalis)

Next on this list is Edmontosaurus. It is characterized by having a beak-shaped mouth, short limbs and a very long, pointed tail.

7. Diplodocus († Diplodocus longus)

Diplodocus is considered one of the longest land animals that has ever existed.

Fossils of this herbivorous dinosaur showed that these animals existed during the Late Jurassic period. Most of their fossils have been excavated in the Rocky Mountains of the western United States.

Due to its enormous size, Diplodocus also required enormous amounts of plant material in order to survive. Scientists have theorized that its blunt teeth functioned for cutting plants, as Diplodocus swallowed food whole without even chewing.

It is interesting to know that, having such dimensions and body structure, this dinosaur did not have the ability to raise its long neck above five meters from the ground.

8. Hadrosaurus († Hadrosaurus foulkii)

Literally means “strong lizard.” Hadrosaurus is a genus of herbivorous dinosaur that lived in parts of North America during the Late Cretaceous period.

Hadrosaurus had a beak-shaped mouth and jaw that were designed to crush plant matter such as pine needles and cones.

It is also important to note that only one skeleton of this dinosaur has ever been found. This fossil was missing a skull, making it difficult for scientists to analyze it. appearance hadrosaur.

9. Nodosaurus († Nodosaurus textilis)

Another famous herbivorous dinosaur is the Nodosaurus, which is very noticeable for its “armor”.

This dinosaur was a herbivore. He had a rather narrow head with an elongated mouth. Interestingly, the nodosaur had cavities in its skull that separated its mouth from its nasal passages, thus making it capable of eating and breathing at the same time.

Individuals of this genus existed from the late Jurassic period until the early Cretaceous period. Interestingly, at this time the lands of Alabama were divided into two parts: the northern part was covered with forests, and the southern part was covered with small lakes.

10. Ankylosaurus († Ankylosaurus magniventris)

The name comes from ancient Greek. ??????? ??????, which means "bent lizard". Ankylosaurus is a genus of armored dinosaur that existed in parts of the western United States and Canada during the Late Cretaceous period.

Like Stegosaurus, this massive dinosaur had a body also covered with bony plates (called "scutellums"). These scutes grew on different parts of the dinosaur's body, such as the neck, back and hips.

This dinosaur was a herbivore that fed on low-lying vegetation. The beak-shaped mouth allowed the animal to tear leaves from plants. In addition, studies have shown that he could swallow huge quantities of plants without even chewing.

Dinosaurs, which translated from Greek means terrible (terrible) lizards (lizards), are a superorder of above-ground vertebrates that existed and led an active lifestyle throughout Mesozoic era. Dinosaurs are considered the first vertebrates to settle throughout the planet, while their ancestors, amphibians, were forced to live only near bodies of water, to which they were attached due to the specific nature of reproduction. Finds of the first representatives of dinosaurs date back to 225 million BC. e. Over the history of its existence, which lasted for 160 million years, this superorder multiplied enormously, giving rise to a huge number of varieties. Scientists estimate that the number of dinosaur genera at the time of their peak prosperity could reach 3,400, although so far, as of 2006, only 500 of them have been confidently described. Each genus had an indefinite number of species. As of 2008, 1,047 species of these ancient vertebrates had been described. And on at the moment, as a result of new archaeological discoveries, this number is increasing.

At the border of the Mesozoic and Cenozoic, a certain global shock occurred, which served mass extinction of dinosaurs, after which only pitiful units remained of the reptiles that had dominated throughout the Mesozoic.

Classification of dinosaurs using the pelvic bone method

Dinosaurs can be classified in different ways. For some, due to the specifics of their works and literary works, it is convenient to sort the ancient vertebrates of the Cretaceous period by size, for others by their habitat, since at that time there were aquatic reptiles, land reptiles and aeronautics. Some people prefer to divide dinosaurs into bipeds and quadrupeds. But the main generally accepted form of classification is dinosaur classification using the pelvic bone method, proposed back in 1887 by the famous English paleontologist G. Seeley.

Rice. 1 - Classification of dinosaurs

Despite the fact that the ancestors of all dinosaurs without exception are considered to be a group of ancient reptiles archosaurs, at the beginning of the Triassic, their development took different paths. It was from this time that it happened division of reptiles based on the structure of the pelvis to:

• Lizard-pelvic;
• ornithischians.

But this does not mean at all that all lizards originated from lizards, and birds came from ornithischians. These are conventional names, associated only with the fact that in lizards the pubic bones of the pelvis were primarily directed forward, in the manner of modern crocodiles, while in ornithischians they were directed backwards, in the manner of birds.

It would be difficult to determine which group this or that dinosaur belongs to. These groups differ much more clearly in the structure of their jaws. Lizards had jaws with rows of teeth arranged strictly along the edges in one row, reaching to the tip of the muzzle. All teeth had a conical or chisel shape and were each located in its own separate cell. Ornithischians had lower jaws ending in the anterior part with a predentary bone. Often there were no teeth in the front part and the upper jaw. Often, the front part of ornithischian dinosaurs simply looked like a massive, horny turtle beak.

Lizard-hipped dinosaurs

Lizard-hipped dinosaurs(Fig. 2) were divided into:

• Theropods- appeared at the boundary of the Cretaceous and Jurassic and are the largest representatives of predatory carnivorous reptiles that existed until the end of the Cretaceous period and the worldwide cataclysm that caused mass extinction species.
• Sauropodomorphs- also originated in the Late Triassic, some of which were the most gigantic creatures in the entire history of the Earth. All of them were herbivores and were, in turn, divided into two more subgroups, namely, prosauropods who lived in the Late Triassic - Early Jurassic and the later and more developed sauropods that replaced them closer to the middle of the Jurassic.

Rice. 2 - Lizard-hipped dinosaur

Theropods were mostly bipedal predators, but there were also omnivores, such as therizinosaurus or ornithomimids. Some of the theropods, such as Spinosaurus, reached 15 meters in height. These predatory representatives of lizards had three advantages over other dinosaurs, which were:

• extreme agility and speed of movement;
• unusually developed vision;
• freedom of the front paws, since they ran on two unusually developed hind paws, and thus could freely perform any other functions with their front paws.

Giant growth often had detrimental consequences for theropods. For example, a tyrannosaurus, catching up with its prey, had to be very careful when running, since with its impressive dimensions (one of its hind limbs reached a height of 4 meters), any wrong step, any bump or uneven ground could cause a fall, which often led to tangible and sometimes fatal injuries. In turn, theropods are classified to:

• coelurosaurs, small and nimble bird-like dinosaurs such as ornithomimes and velociraptors;
• carnosaurs, large predators, examples of which were the aforementioned Tyrannosaurus and Allosaurus.

Sauropodomorphs had a sacral brain that was 20 times larger than the brain. Despite their enormous weight and size, they became frequent victims of predatory dinosaurs. The enormous size of these ancient reptiles was a consequence of the increase in intestinal mass necessary for the digestion of hard-leaved plants. As a result, along with the stomach, the rest of the body was forced to increase in size. Examples of such lizards were camarosaurs, giraffatitans, brachiosaurs, etc.

Let's take a closer look at theropods using the example of one of the most numerous predators of the Middle Jurassic - allosaurus(Fig. 3). On average, these predators reached a height of 3.5 meters at the withers and 8.5 meters in length from muzzle to tail. Their habitat was the North American, Southern European and East African parts ancient continent Pangea.

Rice. 3 - Allosaurus

Allosaurs had a fairly large skull, their jaws were equipped with a huge number of sharp teeth. In order to balance the body when moving, in contrast to the massive head, there was an equally massive tail, with which the animal often knocked its victims off their feet. The massive head was often used for the same purpose. Compared to other large terrapods, allosaurs were relatively small, but this gave them more maneuverability and mobility. There is also evidence that large dinosaurs, such as some representatives of sauropods, like brontosaurus and thyreophora, like stegosaurus, were hunted by herd methods, like modern wolves. Although many scientists are skeptical that these animals could coexist in packs. In their opinion, for this they had too primitive mental development and extremely strong ferocity and aggressiveness.

Ornithischian dinosaurs

Despite their name, scientists have proven that it was not they, but the lizard-hipped dinosaurs that later became the avian ancestors. But, returning precisely to ornithischian dinosaurs(Fig. 4), note that they classified into two main suborders, namely:

• thyrophores;
• cerapods.

Rice. 4 - Ornithischian dinosaur

TO thyreophores include herbivorous dinosaurs such as ankylosaurs and stegosaurs. A distinctive feature of these lizards was that their body was partially covered with shell armor, and there were huge shield-like growths on their backs.

In rank cerapods includes marginalocephals, such as ceratopsians and pachycelosaurs and all ornithopods, the most widespread representative of which was iguanodon(Fig. 5).

Iguanodons had their peak in distribution in the first half of the Cretaceous, and inhabited vast areas of the European, North American, Asian and African parts of Pangea. The 12-meter and 5-ton iguanodons walked on two massive hind legs; in the front of their muzzle they had a massive beak, with which they plucked the plants they needed. Next came rows of teeth, more similar to the teeth of iguanas, only much larger.

Rice. 5 - Iguanodon

The forelimbs of iguanodons were a quarter the size shorter than the hind limbs. The thumbs were equipped with spines, with the help of which the animal defended itself from predators. The most mobile of the fingers of the forelimbs were the little fingers. It should be noted that iguanodons could not run, their hind limbs were adapted only for leisurely walking, which is why they often became victims of predators such as allosaurs, tyrannosaurs, etc. The hind limbs had three fingers, like modern chickens, and their spine and massive tail were supported by strong tendons.

Problems of classification of dinosaurs in our time

Many scientists insist that large number The already described dinosaurs did not previously exist, since some of the described varieties were nothing more than doubles of previously described species. The difference between them was supposedly only that they were either at an earlier or at a later stage of development. Also, a fairly large group of scientists insists that about 50% of all dinosaurs found were classified and named incorrectly.

Thus, current paleontologists are divided into two camps. While some continue to further divide the bulk of the found remains of ancient reptiles into all new species based on those identified, both significant and not so significant distinctive features, others completely doubt the correctness of the species described earlier.