Dinosaurs are a group of lizards, or reptiles, that flourished during the Mesozoic era - the era of middle life on our planet. Together with them, other species of reptiles lived on Earth - crocodile-like, flying lizards, flat-toothed and snake-like, fish-like and scaly species of lizards. The differences between dinosaurs were so great that scientists have great difficulty establishing their relationships. Dinosaurs were the size of a cat or a chicken, and 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 on the bottom of the body, and not on its sides, like most modern lizards. Therefore, dinosaurs can also be called running reptiles. What were the dinosaurs like? this moment not known for sure. Archaeological excavations are still being carried out, as a result of which more and more new species of dinosaurs are being discovered every year. Over 150 years of work by paleontologists, with the help of remains and skeletons, about 500 species of these animals were discovered. But in fact, over 10,000 remains were found. And this indicates that there may have been over 4,000 species of dinosaurs that lived during different eras of the Jurassic and Cretaceous periods.
If you look at comparative characteristics of what dinosaurs used to be like, one can notice the tendency of their great diversity and prevalence in to the globe. Dinosaurs flew, swam, crawled, they were of various sizes and bizarre shapes:
- Nothosaurs and flattooths were similar to modern lizards with a crest, with a swimming tail flattened on the sides.
- Crocodiles and mososaurs were elongated and moved by twisting their tails.
- 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 leather membrane, like those of modern bats. And the fourth finger, from which the skin was stretched, was greatly elongated.
The best
Well, now let's talk about records. Are you interested in knowing which is the largest dinosaur and which is the smallest, which are carnivores and which are herbivores? Let's look at the records among dinosaurs below:
- Most small dinosaur- Cosmognathus, whose length was approximately 70 cm and weight about 3 kg.
- The tallest dinosaur is the Brachiosaurus, whose length reached 23 meters and weight was 30-40 tons.
- The longest dinosaur is Diplodocus, whose length could reach 52 meters.
- The most toothy dinosaur is the ornithomimid, which had about 220 sharp teeth.
- The smartest dinosaur is presumably a troodontid, which had the largest brain in terms of body size compared to other dinosaurs.
- The largest and heaviest dinosaur was apparently a titanosaur, which lived in Antarctica and weighed, according to some estimates, about 100 tons.
The most common types
Well, our last question concerns what types of dinosaurs were the most common, and are still found today greatest number their remains. These are Triceratops, Tyrannosaurus, Pterodactyl, Diplodocus.
- Triceratops is a horned, herbivorous dinosaur that lived on Earth during 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 lizard today. The largest predator, whose weight reached 4 tons and 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 of them are found in museums. It is believed that this may be the longest land dinosaur; according to scientists, its length could reach 52 meters.
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 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 places 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 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. Some are comfortable due to the specifics of their work and literary works sort ancient vertebrates of the Cretaceous period by size, some by 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, predators large sizes, 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 such large dinosaurs, like some representatives of sauropods, like brontosaurus and thyreophora, like stegosaurus, they hunted in a herd method, 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 such herbivorous dinosaurs, like 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 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 ever new species based on the identified significant and not very distinctive features, others completely doubt the correctness of the species described earlier.
We are all familiar with the classic names of dinosaurs, such as Stegosaurus, Apatosaurus and Tyrannosaurus rex, which is often called simply 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 less happen famous names dinosaurs - Spinops, Bistahieversor and Pantydraco? Let's try to figure out what scientists use when choosing official names for their favorite lizards >>
At the dawn of paleontology, the issue was resolved simply by adding the Greek ending -saurus (–saurus) to the keyword, that is, actually, a lizard. The very first dinosaur to receive an official name back in 1824 was Megalosaurus, or “huge lizard.” True, the next dinosaur to be described in 1825 was named Iguanodon, that is, literally “iguana tooth.” But still, the overwhelming majority of dinosaurs that became famous in the 19th century received names ending in -saurus.
The first part of a typical dinosaur name, traditionally going back to Latin or Greek roots, usually emphasizes main feature ancient animals. For example, when Yale University paleontologist O.C. Marsh coined the name Stegosaurus, which means “roof lizard,” in 1877, he began with the mistaken assumption that the dinosaur’s dorsal plates formed a fragile outer covering. Marsh's other godson, Triceratops, also has a description of its own appearance contained in its name. After all, the name given to it in 1889 literally translates as “three-horned face.” Indeed, it cannot be confused with any other dinosaur.
However, some dinosaur names have rather strange meanings. Despite the fact that Allosaurus was a dominant predator and even the hero of many movies, its name simply translates as “another lizard.” Probably, from the first specimen found, it became clear to the paleontologists who studied it that this animal was different from those found previously.
Some dinosaur skeletons, by the way, can receive proper names in addition to specific ones. The Field Museum of Natural History (Chicago) is home to a T. rex named "Sue", and National Museum Natural History (Washington) - Triceratops Hatcher. In general, the taxonomy of dinosaurs uses the same nomenclatural rules as other animals. First comes the genus name - for example, Brontosaurus, and after it comes the species name: 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 very serious matter. “Choosing a name for a new dinosaur species has always been a difficult task for me,” says North Carolina Museum of Natural Sciences paleontologist Lindsay Zanno. After all, these names play a big role not only for communication between scientists. 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 generate interest, bringing extinct species back to life in the collective imagination,” adds Dr. Zanno.
But even in the most serious matters there is sometimes a place for stupidity. The long-necked dinosaur with muscular legs was named Brontomerus, which literally translates to “rattling thighs.” This name was coined by Mike Taylor and his colleagues in 2011. And in 2012, another paleontologist, Michael Ryan, a paleontologist at the Cleveland Museum of Natural History, examined with his colleagues a specimen that was believed to belong to a representative of Centrosaurus ), that is, "spiked lizards". Scientists have found that the specimen actually belongs to another species, which they called Coronosaurus - or "crowned lizard."
But, Ryan recalls, his colleague paleontologist Jim Gardner throughout the study called it Broccoliceratops because of the knobby projections on its crest. "I'm sure Jim came up with 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 happened with Wendiceratops, described there by Ryan and David Evans in 2015. The lizard received this nickname in honor of its discoverer Wendy Sloboda, and then it became official scientific name animal.
Dinosaurs are often named after the peoples or tribes where the discovery was made. In the 1980s, duck-billed dinosaur bones found in the Colville River region of Alaska were identified as the remains of Edmontosaurus, a widespread and well-studied Cretaceous herbivore. But last year, paleontologist Hirotsugu Mori and colleagues determined that the bones belonged to another, previously undescribed species, which they called Ugrunaaluk kuukpikensis. The name is translated from the Inupiaq language as "ancient animal that grazes on the Colville River."
Study co-author Patrick Druckenmiller suggested giving this name. "He believed that the indigenous peoples of Alaska knew that the bones belonged to a herbivorous reptile before scientists found them," Mori said.
Appealing to human culture, and mythology in particular, is very popular among paleontologists, says Zanno: "It's a way to connect science and imagination - two sides of the same coin, although we often don't realize it." As an example, Zanno cites a large oviraptorosaur that resembled a flightless parrot.
“It was clear that the name should emphasize its enormous size, but also, I would like to transport the audience to a time long past, when our planet was a completely different, almost unimaginable world,” explained the paleontologist. And he chose the name Hagryphus giganteus for the new animal, which “combines the name of the Egyptian god of the western desert Ha and the name of the mythical beast griffin.” The specific name indicates large size 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 the golden age of paleontological discoveries: the new kind dinosaurs are described on average every two weeks. And estimates of the number of fossils not yet found indicate that we have only discovered and described a small fraction of all dinosaur species.
Gradually, the methods of coming up with names for new species of dinosaurs are changing. "My generation is probably the first that did not have to study Greek and Latin languages during training,” says Ryan. “Over time, ignorance of these languages increases and scientists move further and further from previous taxonomic traditions.”
All this, coupled with the fact that researchers are also influenced by pop culture, has led to a noticeable change in the names of dinosaurs. The snaggle-toothed “vicious lizard” Masiakasaurus knopfleri received a specific name in 2001 in honor of Dire Straits guitarist Mark Knopfler – after all, it was to the music of this band that the remains of the dinosaur were discovered.
Nevertheless, the anatomical features, locations, and names of the authors of the discovery that are 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 a genus name, while a species name may be given in honor of some geographical feature or person. But if you discovered a new species of beetle with a Superman sign on its abdomen, it would be difficult to resist giving it has an obvious name,” Ryan concluded.
Based on materials from the Smithsonian.com portal
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). As a distinct group, dinosaurs have been identified by a set of (mostly obscure) anatomical features, but the main thing that makes them easier to identify and distinguishes them from archosaurs is bipedal or quadrupedal walking, 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), may push the roots of the dinosaur family tree back to 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, landscapes South America abounded in 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! 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 represented a short-lived offshoot from the family tree of early dinosaurs, or were technically archosaurs rather than 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 striking 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 of North America, and then further into 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, but it may have something to do with walking upright or having a more complex lung structure.
By the beginning of the 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 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 arise from such a modest ancestor).
List of first dinosaurs
| Name (genus or species) | Short description | Image |
| a genus of lizard-hipped dinosaurs related to herrerasaurs (Herrerasaurus). | ||
| Coelophysis (Coelophysis) | a genus of small dinosaurs that lived in North America. |  |
| a genus of small dinosaurs, a close relative of Compsognathus (Compsognathus). |  |
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| Compsognathus (Compsognathus) | a genus of dinosaurs the size of large chickens 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) | a species of ancient carnivorous dinosaur 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. |  |
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| 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 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 |  |
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| a genus of small reptiles from the suborder of theropods that lived in North America during the Jurassic period. |  |
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| 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. |  |
