What kind of dinosaurs are there? Dinosaurs (alphabetically)

It is no secret that during the existence of our planet, the world of flora and fauna has changed several times. Dinosaurs did not survive to our times, but their existence is confirmed by numerous excavations.

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Types of dinosaurs, their classification

Paleontologists say that dinosaurs inhabited our planet for more than a hundred million years. Scientists came to such conclusions after many years of excavations, which allowed them to invade the bowels of the earth and find there numerous remains of giant birds and animals. One can only guess what reality was like in those days.

Today we will take a closer look at what types of dinosaurs there are, and what information about them is available today. In general, when you start to become interested in these animals, you are amazed at how much paleontologists know, but no one has ever seen these animals with their own eyes. Now these are the heroes of horror films, fairy tales for children, and so on, it is thanks to the artists that we have a clear idea of ​​what such unusual creatures really looked like. Very often, different dinosaurs are compared to dragons.

Scientists, unfortunately, have not been able to come to a common conclusion as to why dinosaurs suddenly became extinct on our planet. Although in that era not only dinosaurs disappeared, but also many inhabitants of the underwater world. One theory says that it was not the Earth’s climatic conditions that changed dramatically, but the dinosaurs were unable to live in the new environment, so one after another they began to die. The second theory (more realistic) says that 65 million years ago a huge asteroid crashed onto our planet, destroying many earthly creatures.

We will not go into detail about why huge creatures disappeared from the face of the Earth; it will be much more interesting to talk about what paleontologists know today. And they know a lot; from the remains they were able to establish what kind of dinosaurs existed, tell approximately how many species there were, and also give them specific names.

For the first time, the English biologist Richard Owen spoke about dinosaurs; it was he who called the animals with this term (by the way, “dinosaur” is translated from Greek as a terrible lizard). Until 1843, scientists did not put forward theories about the existence of dinosaurs. Their remains were attributed to either dragons or other giant mythical animals.

Now the list of species is simply huge and each genus has its own name. For example, you will be interested to know what the two largest and most ancient groups of these animals are. Maybe the names will seem funny to some, but these are lizard-hipped and ornithischian creatures. Next we list the most famous and, in our opinion, the main species or types of dinosaurs. Don’t be surprised that representatives of the most famous breeds could swim and fly beautifully, and not just move on land. A lot of information was studied by scientists before they were able to draw conclusions that dinosaurs can be divided into the following groups:

• predatory;
• herbivores;
• flying;
• aquatic.

Paleontologists knew exactly how to distinguish one type from another, they carried out more and more research, as a result of which the world learned about trinosaurs, ichthoisaurs, pliosaurs, tyrannosaurs, ornithocheiruses, and so on.

The exact number of species of dinosaurs that existed cannot be established, and it is unlikely that this will ever be known. There are so many nuances to studying fossils. The number of varieties is said to range from 250 to 550 and these numbers are constantly changing. For example, some species were identified only by excavating a single tooth or vertebra. Over time, scientists realize that some species that were previously considered different can actually be classified as the same thing. So no one dares to draw precise conclusions. Perhaps most types of dinosaurs exist only in the imagination of paleontologists and other sensation-seekers. But since these huge creatures have disappeared from our planet, it means that it had to be so. Nothing happens by chance, especially the extinction of real giant predators.

Swimming dinosaur: myth or reality?

Paleontologists claim that aquatic dinosaurs did exist. To be honest, the population of the seas and oceans in those days was not so harmless. Waterfowl dinosaur fish would happily eat everyone. And they cannot even compare with the most dangerous sharks today. The size of the monsters exceeded the size of modern whales. Huge animals could happily have a snack, for example, on another dinosaur, which, by chance, was in the wrong place at the wrong time. Some fish grew up to 25 m (for comparison, a standard nine-story building is 30 m).

Sea monsters were classified as follows:

• plesiosaur (a long-necked creature that lived underwater all the time, sometimes surfacing to breathe air or grab a flying bird);
• Elasmosaurus weighed about 500 kg, had a small but movable head on a huge (8 m) neck;
• mosasaurs lived in the seas and oceans, but moved a little like a snake;
• Ichthyosaurs are very warlike and bloodthirsty animals that lived and hunted in packs. There were practically no insurmountable obstacles for them;
• nothosaurus led a dual lifestyle (on land and in water), feeding on small creatures and fish;
• Liopleurodons lived exclusively in an aquatic environment, could hold their breath for several hours, dive to depths and hunt there;
• Shonisaurus is a completely harmless reptile that was an excellent hunter and ate mollusks, octopuses, and squid.

Very little is known about the existence of two-headed creatures; many types of dinosaurs had long claws that helped them move faster. Some types of large sea inhabitants were:

• with a collar around the neck;
• with hood;
• with a ridge on the back (sometimes with two ridges);
• with spikes;
• with a tuft on the head;
• with a mace on the tail.

Herbivorous dinosaurs: their classification

This is most likely the most peaceful species of huge creatures. They calmly chewed grass, were happy and entered into battle solely for the purpose of self-defense. Rarely did herbivores attack first. Moreover, dinosaurs of this type were not at all weak, defenseless animals. A powerful skeleton, huge horns, a tail with a club, unrealistically huge sizes, strong limbs that could immediately strike on the spot - all these are characteristics of completely peaceful animals.

There were several types of herbivorous creatures:

• stegosaurs - they had peculiar ridges on their bodies, chewed grass, and swallowed stones from time to time to improve digestion;
• euoplocephalus, which was covered in spines, a bony shell and had a club tail. This is a truly scary monster;
• brachiosaurus - could eat about a ton of greenery in just a day;
• Triceratops had beaks and horns, lived in herds, and easily defended themselves from enemies;
• hadrosaurs were quite large, but very vulnerable, it is still a mystery how they survived.

This is not a complete list of species of grass dinosaurs.

Predatory dinosaurs

Still, most dinosaurs were predators by nature. They had a powerful body structure, huge teeth, horns, and shells. All this allowed the animals to rise above other living beings; dinosaurs often fought with their relatives. The strongest always won, there was no talk of any family ties. The tyrannosaurus rex was considered the most popular predator; you can find a lot of interesting information about it and watch a video. T-Rex is the hero of many horror films, because this born hunter was truly scary, disgusting, ruthless, and bloodthirsty.

Long-necked dinosaur (name and species)

Among herbivorous, marine and predatory species, there were breeds that were distinguished by unrealistically long necks. For example, diplodocus is a herbivore whose neck consisted of 15 vertebrae. He could easily reach branches from the tallest trees.

Flying species or dinosaur birds actually had wings, scales, and sometimes even feathers. The peculiarity of these creatures were huge, very sharp teeth, which cannot be said about modern birds. These are pterodactyls, pterosaurs, archeopteryx. Ornithocheirus was the size of a small airplane, had a light skeleton, and a crest on its beak. Such “birds” lived not far from large bodies of water.

Quite educational and also interesting to read about the inhabitants of the Jurassic period, isn’t it? At that time, the population of the Earth was completely different, scary and incomprehensible to us, its modern inhabitants.

The beginning of the story was the climate changes that occurred on Earth 300 million years ago. There was a significant increase in average temperature, which contributed to the extinction of some species and the spread of others. In particular, reptiles began to flourish.

Both the number of individuals and the number of species increased. The ancestors of dinosaurs, archosaurs, also descended from them. Modern representatives of this group of reptiles are crocodiles. Archosaurs of the Permian period were distinguished by the specific structure of their teeth, as well as a specific protective covering of the skin - scales. Like modern crocodiles, they are eggs.

Carnivorous dinosaurs fed mainly on small mammals. There were also herbivorous dinosaurs with a plant diet.

After the Mass Permian, only 5% of pre-existing species, and the ancestors of dinosaurs, managed to survive this ecological revolution. Dinosaurs themselves arose 230 million years ago. The earliest species of dinosaur known to scientists is the Staurikosaurus. It was about 2 m long and its weight reached 30 kg. Staurikosaurus was a predator and walked on its hind legs.

The Age of Dinosaurs and Their Decline

Gradually, dinosaurs became an increasingly diverse group of creatures, capturing more and more new habitats. Dinosaurs could also live in water, competing with large predatory fish. Flying dinosaurs gradually appeared. Also, over time, the sizes of reptiles became more and more diverse - their weight could reach 200 kg or more.

The heyday of dinosaurs occurred during the Cretaceous and Jurassic periods, when dinosaur species made up more than half of all species on Earth. In total, the remains of about 500 species of dinosaurs were found, but scientists believe that there were significantly more of them - up to 2000 during the entire existence of this superorder.

The largest dinosaurs were herbivores or lived in water.

The exact reason for the extinction of dinosaurs remains unknown. One theory suggests that the dinosaurs died due to a meteorite impact and the resulting tsunami and other disasters. Other scientists believe that the cause was gradual climate change, which led to the extinction of not only dinosaurs, but also a number of other species - up to 20% of flora and fauna species disappeared. What is known for sure is that dinosaurs disappeared at the end of the Cretaceous period - about 65 million years ago. The dominance of reptiles was replaced by the widespread distribution of mammals.

Dinosaur species of this group lived in the late Jurassic period on the territory of modern North America about 150 million years ago. Paleontologists consider Diplodocus one of the most easily identifiable dinosaurs. Moreover, this species is the largest of all dinosaurs known from complete skeletons found. Diplodocus were herbivores, and their huge size was a deterrent to the predatory lizards of those times - ceratosaurs and allosaurs.

Allosaurus - the threat of diplodocus!

Within the framework of this article, we will not be able to consider all types of dinosaurs with names, so we will turn only to the most prominent and famous representatives of these legendary giants. One of them is Allosaurus. This is a representative of the genus of predatory dinosaurs from the theropod group. Like Diplodocus, Allosaurus existed in the Jurassic period about 155 million years ago.

These creatures walked on their hind legs and had very small forelimbs. On average, these lizards reached a length of 9 meters and a height of 4 meters. Allosaurs were considered large bipedal predators of the time. The remains of these insidious creatures were found in the territory of modern Southern Europe, East Africa and North America.

Ichthyosaurs - legendary fish lizards

They represent an extinct order of large marine reptiles that reached a length of 20 meters. Outwardly, these lizards resembled modern fish and dolphins. Their distinctive feature was their large eyes, protected by a bone ring. In general, at a short distance, ichthyosaurs could easily be mistaken for fish or dolphins.

The origin of these creatures is still in question. Some paleontologists believe that they come from diapsids. This version is supported only by guesswork: apparently, the shoot of ichthyosaurs somehow branched off from the main stem of diapsids even before this subclass divided into archosaurs and lepidosaurs. However, the ancestors of these fish lizards are still unknown. Ichthyosaurs became extinct about 90 million years ago.

Dinosaurs take to the skies

At the end of the Triassic period, the first flying species of dinosaurs appeared on the planet, which appeared unexpectedly in the fossil record. It is curious that they were already fully formed. Their direct ancestors, from whom they developed all this time, are unknown.

All Triassic pterosaurs belong to the group of rhamphorhynchus: these creatures had huge heads, toothed mouths, long and narrow wings, and a long and thin tail. The size of these "leather birds" varied. Pterosaurs - as they were called - were basically the size of both seagulls and hawks. Of course, there were 5-meter giants among them. Pterosaurs went extinct about 65 million years ago.

Tyrannosaurs are the most famous dinosaur species

The list of ancient lizards would be incomplete if we did not mention the most majestic dinosaur of all times and eras - the tyrannosaurus. This insidious and dangerous creature fully lives up to its name. This creature represents a genus from the group of coelurosaurs and the suborder of theropods. It includes a single species - the Tyrannosaurus rex (from the Latin “rex” means king). Tyrannosaurs, like Allosaurus, were bipedal predators with massive skulls and sharp teeth. The limbs of the tyrannosaurus were a complete physiological contradiction: massive hind legs and tiny hook-shaped front legs.

Tyrannosaurus is the largest species within its own family, as well as one of the largest land predatory lizards in the entire history of our planet. The remains of this animal were found in the west of modern North America. According to scientists, they lived about 65 million years ago, that is, it was during their century that the death of the entire dynasty of ancient lizards occurred. It was the tyrannosaurs that crowned the entire great era of dinosaurs, which ended during the Cretaceous period.

Feathered Legacy

It is no secret to many people that birds are direct descendants of dinosaurs. Paleontologists saw a lot in common in the external and internal structure of birds and dinosaurs. It should be remembered that birds are the descendants of land lizards - dinosaurs, and not flying lizards - pterosaurs! Currently, two subclasses of ancient reptiles are “hanging in the air”, since their ancestors and exact origins have not been established by paleontologists. The first subclass is ichthyosaurs, and the second is turtles. If we have already dealt with ichthyosaurs above, then with turtles nothing is clear at all!

Are turtles amphibians?

Therefore, it is clear that, when considering a topic such as “Species of Dinosaurs,” one cannot fail to mention these animals. The origin of the turtle subclass is still shrouded in mystery. True, some zoologists still believe that they originated from anapsids. However, they are opposed by other scientists who are sure that turtles are the descendants of some ancient amphibians. And they are not at all dependent on other reptiles. If this theory is confirmed, then a big breakthrough will occur in the science of zoology: it may happen that turtles will not have the slightest relation to reptiles at all, because then they will become... amphibians!

1. Triceratops (Triceratops horridus)

Triceratops is a herbivorous dinosaur that lived on Earth during the late Cretaceous period in the 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. It had a long neck allowing it to easily reach 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 the appearance of the 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 the 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 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 on the:

• 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 the mass extinction of 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 legs, since they ran on two unusually developed hind legs, and thus could freely perform any other functions with their front legs.

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 its turn, theropods are classified on the:

• 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 of the ancient continent of 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 a large number of already described dinosaurs did not previously exist, since some described varieties were nothing more than duplicates 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 ever new species based on the identified significant and not very distinctive features, others completely doubt the correctness of the species described earlier.