See types of dinosaurs. The very first dinosaurs on the planet

23.11.201927.05.2017

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 claim that dinosaurs inhabited our planet for over 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 numerous remains of giant birds and animals there. What was the reality in those days, one can only guess.

Today we will take a closer look at what varieties of dinosaurs are, and what information about them is available today. In general, when you start to be interested in these animals, it is amazing how much paleontologists know, and 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 how such unusual creatures really looked like. Very often different dinosaurs are compared to dragons.

Scientists, unfortunately, have not been able to come to a unanimous conclusion why dinosaurs suddenly died out on our planet. Although not only dinosaurs disappeared in that era, but also many inhabitants underwater world. One theory says that it is not the Earth that has changed dramatically climatic conditions, and dinosaurs could not live in a new environment, so one by one they began to die. The second theory (more realistic) says that 65 million years ago a huge asteroid crashed into our planet, which destroyed many earthly creatures.

We will not go into details 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 managed to establish which dinosaurs existed, to report approximately how many species there were, and also to give them certain names.

For the first time, the English biologist Richard Owen spoke about dinosaurs, it was he who called animals by 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 are the two largest and most ancient groups of these animals. Maybe the names will seem funny to someone, but these are lizard and ornithischian creatures. Next, we list the most famous and, in our opinion, the main species or types of dinosaurs. Do not be surprised that representatives of the most famous breeds could perfectly swim, fly, and not just move on land. A lot of information was studied by scientists before they could draw conclusions that dinosaurs can be divided into such groups:

predatory;
herbivores;
flying;
water.

Paleontologists knew exactly how to distinguish one type from another, they were doing more and more research, as a result of which the world learned about trinosaurs, ichthosaurs, pliosaurs, tyrannosaurs, ornithocheirs 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 many nuances in the study of fossils. The number of varieties is said to range from 250 to 550 and these numbers are constantly changing. For example, some species have only been identified from the excavation of a single tooth or vertebra. Over time, scientists realize that some species that were previously considered different can actually be attributed to the same thing. So no one can draw firm conclusions. Perhaps most types of dinosaurs exist only in the fantasy of paleontologists and other sensationalists. But since these huge creatures have disappeared from our planet, it means that it was necessary. Nothing happens by chance, and especially the extinction of real giant predators.

Swimming dinosaur: myth or reality?

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

Sea monsters were classified as follows:

plesiosaurus (a long-necked creature that lived all the time under water, sometimes surfaced 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;
the notosaurus led a dual lifestyle (on land and in water), eating small creatures and fish;
Liopleurodon lived exclusively in aquatic environment, could hold their breath for several hours, dive to the depths and hunt there;
Shonisaurus is a completely harmless reptile that was an excellent hunter and fed on mollusks, octopuses, and squids.

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

with a collar around the neck;
with a hood;
with a crest on the back (sometimes with two crests);
with spikes;
with a tuft on his head;
with a mace on the tail.

Herbivorous dinosaurs: their classification

This is most likely the most peaceful species of huge creatures. They quietly chewed weed, were happy and entered the fight solely for the purpose of self-defense. Rarely have herbivorous creatures attacked first. At the same time, dinosaurs of this type were not at all weak, defenseless animals. A powerful skeleton, huge horns, a tail with a mace, unrealistically huge sizes, strong limbs that could immediately strike on the spot - all these are the characteristics of completely peaceful animals.

There were several types of herbivorous creatures:

stegosaurus - they had peculiar combs on their bodies, chewed grass, from time to time swallowed stones to improve digestion;
euplocephalus, which was covered with spikes, a bone shell and had a mace on its tail. This is a truly terrible monster;
brachiosaurus - could eat about a ton of greens in just a day;
triceratops had beaks, horns, lived in herds, 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.

carnivorous dinosaurs

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

Dinosaur with a long neck (name and species)

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

Flying species or dinosaur birds did indeed have wings, scales, sometimes even feathers. A feature of these creatures were huge very sharp teeth, which cannot be said about modern birds. These are pterodactyls, pterosaurs, archeopteryxes. Ornithocheirus was the size of a small plane, had a light skeleton, a crest on its beak. Such "birds" lived near large reservoirs.

Quite informative, 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, terrible and incomprehensible to us, its modern inhabitants.

Each of us is familiar with classic titles dinosaurs such as Stegosaurus, Apatosaurus and Tyrannosaurus Rex ( Tyrannosaurus rex), which is often called simply Tirex (T. rex). These Mesozoic fossils became widely known in late XIX- the beginning of the 20th century, when they first began to be exhibited in museums.

But where did these names come from? And how did the lesser-known dinosaur names Spinops, Bistahieversor and Pantydraco come about? Let's try to figure out what scientists are guided by when choosing official names for their favorite lizards >>

At the dawn of paleontology, the issue was solved simply - by adding the Greek ending -saurus (-saurus) to the keyword, that is, in fact, the lizard. The very first dinosaur to receive official name as early as 1824, there was a megalosaurus (Megalosaurus), or "huge lizard". True, the next dinosaur in 1825 was named Iguanodon, that is, literally "iguana tooth". But still, the vast majority of dinosaurs that became famous in the 19th century received names ending in -saurus.

The very first part of a typical dinosaur name, traditionally derived from Latin or Greek roots, usually emphasizes main feature ancient animals. For example, when in 1877 Yale University paleontologist O.C. Marsh coined the name Stegosaurus, which means "roof lizard", he proceeded from the later erroneous assumption that the dorsal plates of this dinosaur formed a fragile outer cover. Another godson of Marsh - Triceratops (Triceratops) - also has a description of his own appearance, contained in the name. After all, the name given to him in 1889 literally translates as "three-horned muzzle." Indeed, you will not confuse it with any other dinosaur.

However, some names of dinosaurs have rather strange meanings. Despite the fact that the Allosaurus was the dominant predator and even the hero of many movies, its name simply translates as "another lizard". Probably, according to the first specimen found, it became clear to the paleontologists who studied it that this animal was different from those found earlier.

Some dinosaur skeletons, by the way, can also receive proper names in addition to specific ones. The Field Museum of Natural History (Chicago) is home to a Tirex named Sue ("Sue"), and the National Museum of Natural History (Washington) is home to the Triceratops Hatcher ("Hatcher"). In general, the same nomenclature rules are used in the taxonomy of dinosaurs as in other animals. First comes the name of the genus - for example, Brontosaurus, and after it - the name of the species: excelsus. From time to time, paleontologists find new species belonging to an already known genus. For example, Velociraptor mongoliensis was found back in 1924, and in 2008 another species of the same genus, Velociraptor osmolskae, was described.

For many paleontologists, choosing the name of an ancient animal is a serious matter. "Choosing a name for a new species of dinosaur has always been a difficult task for me," says Lindsay Zanno, a paleontologist at the North Carolina Museum of Natural Sciences. After all, these names play a big role not only for the communication of researchers. Dinosaurs have their own, and quite significant, niche in pop culture, and an interesting, colorful name is a great way to interest the public. "A well-chosen name will spark interest, bringing extinct species to life in the collective imagination," adds Dr. Zanno.

But even in the most serious business sometimes there is a place for stupidity. The long-necked dinosaur with muscular legs was named Brontomerus, which literally translates as "rumbling hips". This name was coined by Mike Taylor and colleagues in 2011. And in 2012, another paleontologist Michael Ryan, a paleontologist at the Cleveland Museum of Natural History, examined with colleagues a specimen that was thought to belong to a representative of the centrosaurus (Centrosaurus ), i.e. "spiked lizards". Scientists have found that in fact the sample belongs to another species, which they called the coronosaurus (Coronosaurus) - or "crowned lizard".

But, Ryan recalls, his colleague paleontologist Jim Gardner (Jim Gardner) called him broccoliceratops (Broccoliceratops) throughout the study because of the protrusions covered with tubercles on the ridge. "I'm sure Jim suggested the name just as a joke," Ryan recalls. "But it's very expressive."

However, sometimes such working nicknames given to an as yet undescribed dinosaur stick to it forever. This is what happened to Wendiceratops, described in the same place by Ryan and David Evans in 2015. The lizard received this nickname in honor of its discoverer Wendy Sloboda (Wendy Sloboda), and then it became the official scientific name of the animal.

Often, dinosaurs are named after the peoples or tribes in whose places of residence the find was made. In the 1980s, duck-billed dinosaur bones found in the Colville River region of Alaska were identified as remains of Edmontosaurus, a widespread and well-studied Cretaceous herbivore. But last year, paleontologist Hirotsugu Mori and colleagues determined that the bones belonged to a different, previously undescribed species, which they named Ugrunaaluk kuukpikensis. This name, translated from the Inuit language Inupiaq, means "an ancient animal that grazes on the Colville River."

This name was suggested by study co-author Patrick Druckenmiller. "He believed that the Alaska Native peoples knew that the bones belonged to a herbivorous reptile before they were found by scientists," Maury said.

Referring to human culture, and mythology in general, is very popular with paleontologists, Zanno says: "It's a way of linking science and imagination - two sides of the same coin, although we often don't realize it." As an example, Zanno cites a large oviraptorosaurus resembling a flightless parrot.

"It was clear that the name should emphasize its huge size, but in addition, I would like to take the audience to times long gone when our planet was a completely different, almost unimaginable world," the paleontologist explained. And he chose the name Hagryphus giganteus for the new animal, in which "the name of the Egyptian god of the western desert Kha and the name of the mythical griffin beast were combined." The species name at the same time testifies to the large size of the animals. "This is now my favorite combination," Zanno added.

There is no doubt that over time, science will be enriched with even more names - after all, paleontologists are constantly finding new dinosaurs. In fact, we are now living in a golden age of paleontological discovery, with a new species of dinosaur being described on average every two weeks. And estimates of the number of fossils yet to be found suggest that we have discovered and described only a small fraction of all dinosaur species.

Gradually, the methods of coming up with names for new types of dinosaurs are changing. "My generation is probably the first that didn't have to learn Greek and Latin during their studies," says Ryan.

All this, coupled with the fact that researchers are also influenced by pop culture, has led to a marked change in the names of dinosaurs. The crooked-toothed "vicious lizard" Masiakasaurus knopfleri in 2001 received a specific name in honor of Dire Straits guitarist Mark Knopfler (Mark Knopfler) - after all, the dinosaur remains were discovered to the music of this group.

Nevertheless, the anatomical features, localities, and names of the authors of the find traditionally noted in the names still play an important role in the naming of new species, both dinosaurs and other animals. “Researchers emphasize morphological features in the genus name, while the species name can be given in honor of some geographical object or person. But if you were to discover a new species of beetle with the sign of Superman on the abdomen, it would be difficult to resist giving it has an obvious name," Ryan concluded.

Sourced from Smithsonian.com

About 230 million years ago, the first dinosaurs evolved from a population of archosaurs. (Archosauria), which shared the planet with many other reptiles, including animal-like reptiles - therapsids (Therapsida) and pelycosaurs (Pelycosauria). As a distinct group, dinosaurs have been identified by a set of (mostly incomprehensible) 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 location of the bones of the thigh and lower leg. 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 Marazuh (Marasuchus) great for the role of an early dinosaur, and lived with the saltopus dinosaurs (S. elginensis) and procompsognatus (P. triassicus) during the period of transition between these two forms of life.

Recently discovered genus of archosaurs - asilisaurs (Asilisaurus), could shift the roots of the dinosaur family tree to 240 million years ago. There are also controversial footprints of the first dinosaurs in Europe dating back 250 million years!

It's important to keep in mind that archosaurs didn't "disappear" from the face of the earth when they turned into dinosaurs. They continued to live side by side with their possible descendants for the remainder of the Triassic period. And, 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, landscapes South America abounded with similar-looking archosaurs, pterosaurs, ancient crocodiles, and the first dinosaurs.

South America - Land of the First Dinosaurs

The earliest dinosaurs lived in the region of the Pangea supercontinent, 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, part of the attention has shifted to Eoraptor (Eoraptor lunensis), discovered in 1991, a small (about 10 kg) dinosaur.

A recent discovery could overturn our understanding of the South American origin of the first dinosaurs. In December 2012, paleontologists announced the discovery of Nyasasaurus. (Nyasasaurus), who lived in the area of Pangea corresponding to present-day Tanzania, Africa. Amazing! The fossil remains of this dinosaur are 243 million years old, which is approximately 10 million years earlier than the first South American dinosaurs. However, it is possible that Nyasasaurus and its relatives were a short-lived offshoot from the early dinosaur family tree, or technically they were archosaurs rather than dinosaurs.

These early dinosaurs spawned a hardy group of reptiles that quickly (at least in terms of evolution) spread to other continents. The first dinosaurs quickly migrated to the areas of Pangea corresponding to North America (a prime example is the Coelophysis (Coelophysis), thousands of fossils of which have been discovered in the Ghost Ranch, New Mexico, USA, as well as recently discovered tawa (Tawa), which are given as proof of the South American origin of dinosaurs. Small to medium carnivorous dinosaurs such as , 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 are above all others. Everything changed with the mysterious Triassic-Jurassic, which wiped out most of the archosaurs and therapsids. No one knows for sure why dinosaurs survived, perhaps due to upright posture, or a more complex structure of the lungs.

By the beginning of the Jurassic period, dinosaurs began to diversify the ecological niches left behind by their extinct cousins. The split between the lizards mi (Saurischia) and ornithischians (Ornithischia) dinosaurs occurred at the end of the Triassic period. Most of the very first dinosaurs were sauropods, such as sauropodomorphs (Sauropodomorpha), which evolved into bipedal herbivorous prosauropods (Prosauropoda) in the early Jurassic, 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 eocursors. (Eocursor)- a genus of small, bipedal dinosaurs of the late Triassic of South Africa. Eocursor most likely descended from an equally small South American dinosaur (possibly Eoraptor) that lived 20 million years earlier (a clear example of how such a huge variety of dinosaurs could have arisen from such a modest progenitor).

List of first dinosaurs

Name (genus or species)	Short description	Image
	genus of lizard dinosaurs related to the herrerasaurs (Herrerasaurus).
Tselofiz (Coelophysis)	a genus of small dinosaurs that lived in North America.
	a genus of small dinosaurs, a close relative of Compsognathus (Compsognathus).
Compsognathus (Compsognathus)	a genus of dinosaurs the size of a large chicken that lived in the late Jurassic period.
Demonosaurus (Daemonosaurus)	carnivorous reptiles from the theropod suborder (Theropoda).
Elaphrosaurus (Elaphrosaurus)	a genus of carnivorous dinosaurs from the Late Jurassic.
Eodromaeus (Eodromaeus murphi)	kind of ancient predatory dinosaurs from South America.
Eoraptor (Eoraptor lunensis)	a species of small dinosaurs, one of the first of its kind.
	a genus of early dinosaurs named after Godzilla.
Herrerasaurus (Herrerasaurus)	genus of the first carnivorous dinosaurs from the vastness of South America.
Lilienstern	genus of the largest carnivorous dinosaurs of the Triassic period.
Megapnosaurus (Megapnosaurus)	in Greek, the genus name means "big dead lizard."
Pampadromaeus barberenai	ancient species of herbivorous reptiles and ancestor of sauropods.
	genus of one of the earliest dinosaurs in North America.
Procompsognatus (Procompsognathus)	a genus of prehistoric reptiles possibly related to the archosaurs.
saltopus	as in the previous case, it is not known exactly whether saltopus belonged to dinosaurs or archosaurs.
Sanjuansaurus (Sanjuansaurus)	a genus of early dinosaurs from South America.
	a genus of carnivorous dinosaurs from the expanses of England in the early Jurassic period
	a genus of small reptiles from the theropod suborder that lived in North America during the Jurassic period.
Staurikosaurus	primitive carnivorous dinosaur of the late Triassic period.
Tava (Tawa)	a genus of lizard-like carnivorous dinosaurs found in southern North America.
Zupaisaurus (Zupaysaurus)	a representative of early theropods found in what is now Argentina.

Dinosaurs are a group of dinosaurs, or reptiles, that flourished during the Mesozoic era - the era average life on our planet. Together with them, other types of reptiles lived on Earth - crocodile-like, flying lizards, flat-toothed and snake-like, fish-like and scaly types of lizards. Differences Between Dinosaurs Were So Big That Scientists Find Them family ties hardly. Dinosaurs were the size of a cat or a chicken, but they were also the size of whales. Some walked on four legs, others ran on two. Among them were bloodthirsty killers and predators, dexterous hunters, as well as herbivorous and harmless species.

Types of dinosaurs

But there is one feature that unites them, they were all terrestrial animals, their paws were located below the body, and not on its sides, like most of the current pangolins. Therefore, dinosaurs can still be called running reptiles. What were the dinosaurs this moment not known exactly. Archaeological excavations are still being carried out, according to the results of which, every year more and more new types of dinosaurs are discovered. For 150 years of work of paleontologists, with the help of remains and skeletons, about 500 species of these animals have been discovered. But in fact, over 10,000 remains have been found. And this indicates that there could be over 4,000 species of dinosaurs that lived in different eras of the Jurassic and Cretaceous periods.

If you look at the comparative characteristics of what dinosaurs used to be, you can see the trend of their great diversity and prevalence according to the globe. Dinosaurs flew, swam, crawled, they were of various sizes and bizarre shapes:

Nothosaurs and flattooths were similar to modern crested lizards, with a swimming tail flattened on the sides.
Crocodiles and mososaurs were elongated, and moved by twisting tail movements.
Plesiosaurs, sea turtles, pliosaurs resembled a lizard with a crest, and used their hind limbs as fins.
Fish-like lizards, which looked like dolphins, resembled fish in their shape, and moved in the water with the help of their tail.
A distinctive feature of flying dinosaurs was the presence of wings covered with a leather membrane, like modern bats. And the fourth finger, from which the skin was stretched, was greatly elongated.

The best of the best

Well, now let's talk about records. Are you curious to know which is the largest dinosaur and which is the smallest, which are carnivores and which are herbivores? Consider the records among dinosaurs below:

Most little dinosaur- cosmognatus, the length of which was approximately 70 cm, and the weight was about 3 kg.
The tallest dinosaur is the brachiosaurus, whose length reached 23 meters, and the weight was 30-40 tons.
The longest dinosaur is the diplodocus, whose length could reach 52 meters.
The most toothy dinosaur is the ornithomimid, which had about 220 sharp teeth.
The most intelligent dinosaur is supposedly a troodontid, which, in terms of body size ratio with other dinosaurs, had the largest brain.
The largest and heaviest dinosaur, apparently, was a titanosaur that lived in Antarctica and weighed, according to some estimates, about 100 tons.

The most common types

Well, our last question regarding which types of dinosaurs were the most common, and to this day they find the largest number of their remains. These are triceratops, tyrannosaurus, pterodactyl, diplodocus.

Triceratops - horned herbivore dinosaur who lived on Earth in the Cretaceous period, about 70 million years ago. He had three large horns on his head, for which he received his name. It weighed about 12 tons, and was about 9 meters long.
Tyrannosaurus is sometimes the most famous pangolin today. The largest predator, whose weight reached 4 tons, and a height of about 6 meters. All tyrannosaurs had powerful heads and jaws, and the length of the teeth could reach 15 centimeters!
Pterodactyl - inhabited the Earth about 150 - 70 million years ago. The flying lizard, with a long mouth studded with sharp teeth, mainly fed on fish and small creatures. The wingspan could reach 16 meters.
Diplodocus is a herbivorous dinosaur that lived about 150 million years ago. Paleontologists have found the remains of these giants in the best preserved form, and therefore, almost complete skeletons are found in museums. It is believed that this may be the longest land dinosaur, according to scientists, its length could reach 52 meters.

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 to be 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 - a thunderstorm of diplodocus!

Within the framework of this article, we will not be able to consider all types of dinosaurs with names, so we will only turn to the most striking and famous representatives these legendary giants. One of them is the Allosaurus. This is a representative of the genus of carnivorous dinosaurs from the group of theropods. Like diplodocus, allosaurs 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 on the territory of modern Southern Europe, East Africa and North America.

Ichthyosaurs - legendary fish lizards

They represent an extinct detachment of large marine reptiles, reaching a length of 20 meters. Outwardly, these lizards resembled modern fish and dolphins. Their distinguishing feature was large eyes, protected by a bone ring. In general, at a short distance, ichthyosaurs could well 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 conjectures: apparently, the escape of ichthyosaurs somehow branched off from the main diapsid stem even before this subclass split into archosaurs and lepidosaurs. However, the ancestors of these fish lizards are still not known. Ichthyosaurs died out about 90 million years ago.

Dinosaurs take to the sky

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

All Triassic pterosaurs belong to the Rhamphorhynchus group: these creatures had huge heads, toothy mouths, long and narrow wings, and a long and thin tail. The size of these "leather birds" varied. Pterosaurs, as they were called, were mostly the size of both gulls and hawks. Of course, among them were 5-meter giants. Pterosaurs died out 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 rex. This insidious and dangerous creature fully justifies its name. This creature represents a genus from the coelurosaur group and theropod suborder. It includes a single species - a tyrannosaurus rex (from the Latin language "rex" is a king). Tyrannosaurs, like allosaurs, were bipedal predators with massive skulls and sharp teeth. The limbs of Tyrannosaurus Rex were a complete physiological contradiction: massive hind legs and tiny hook-shaped forepaws.

Tyrannosaurus is the largest species within its own family, as well as one of the largest terrestrial 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 in 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 heritage

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

Are turtles amphibians?

And therefore it is clear that, considering such a topic as "Types 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 pundits who are sure that turtles are the descendants of some ancient amphibians. And they do not depend on other reptiles at all. 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!