Small carnivorous dinosaurs. The largest carnivorous dinosaurs in history. Tyrannosaurus rex - a ferocious theropod predator
Appearing about 230 million years ago, in the middle of the Triassic period, dinosaurs began their existence on earth as small carnivores that eventually grew into thousands. various kinds ranging from tiny predators the size of a small dog to huge plant eaters weighing over 80 tons. Although other prehistoric stars such as pterodactyls and ichthyosaurs often mate with dinosaurs, these big lizards(exactly the same with Greek translated "dinosaur") were strictly terrestrial reptiles. They also differed from other animals in a set of unique features, such as the extension of the jaw muscles to the entire skull, which was peculiar only to them.
These traits were probably very impressive as they allowed these most fascinating prehistoric creatures to dominate the earth for over 160 million years. Although researchers are learning more and more about the mysterious beasts every day, constantly discovering more and more new specimens, below are the 10 largest, most interesting and unusual dinosaurs discovered. To begin with, let's introduce you to a dinosaur, in which at first glance there is nothing remarkable, but this is only at first glance, until you hear how he "sings".
10. Parasaurolophus (Parasaurolophus)
Some dinosaurs amaze us with their size, others with their speed, and still others with their cruelty. This dinosaur is famous for its nasal cavity. He wasn't particularly large sizes, did not develop high speed and had neither sharp teeth, nor long claws, nor prickly tails. But if you have a special auditory cortex that can detect the movements of predators from afar, and thanks to which you can warn all your fellows of the approaching danger, you do not need any of the above signs.
The herbivorous member of the hadrosaur family still possessed distinctive feature He had a curved crest on his head. This crest may also have been used to attract a partner or for identification, and it started from the nose and extended to the entire head. The length of the comb was 2.4 meters, and it consisted of several tubes. When the dinosaur made sounds with his "trombone", their frequency was very low, and the sounds were very similar to a siren. This so-called "infrasound" was able to travel very long distances, thus warning other members of the group of approaching danger. Combined with very good hearing and the ability to detect predators at long range, these features were all it took to stay safe at all times.
9. Sinornithosaurus (Sinornithosaurus)
This dinosaur, whose name stands for Chinese bird lizard, was a small turkey-like dinosaur belonging to a family of carnivores. Sinornithosaurus rose to prominence after scientists discovered in late 2009 that the feathered predator may have been "venomous" as well. While other dinosaurs only showed possible signs ability to inject poison into prey, the conclusions regarding this dinosaur left no doubt.
Having some resemblance to other poisonous animals, for example, with snakes, these dinosaurs had a special large pointed tooth, along which the poison went. The researchers also found a special channel in the mouth of the animal, which housed the gland, where the poison accumulated, and from where it came directly to the tooth itself. The back teeth of Sinornithosaurus were shorter and wider, and were intended for chewing. It is likely that he used his fang to inject venom into prey such as birds, pterosaurs, lizards, and mammals and then eat them. This method is not much different from the tactics of the poisonous snakes that exist today.
8. Ankylosaurus (Ankylosaurus)
With a length of 10.7 meters and a weight of 3-4 tons, this dinosaur had practically no rivals equal to it during the period when it roamed the earth in the late Cretaceous period. With back and sides covered with spikes like steel plates, bone eyelids and bone " defense mechanisms Surrounding the outside of its skull and jaws, this herbivorous dinosaur seemed to be completely armored. However, apparently this was not enough for nature, and she also rewarded him with a massive tail capable of striking, with a force of about 43,000 pounds.
Thanks to the upper tail muscle and "floating" vertebrae, his tail swung like a whip at an angle of 45 degrees in any direction at a speed of 77 km / h. In addition to everything, there was also a 45 kg bone mass on the tail, which could easily kill any opponent without even looking. The only thing that does not fit into the image of this mighty animal is its small beak, which was intended for chewing plants.
7. Oryctodromeus Cubicularis (Oryctodromeus Cubicularis)
How could a dinosaur, weighing almost 32 kg, survive in conditions inhabited by predatory animals that were ten times larger than itself? In the case of these small herbivorous dinosaurs that lived at the beginning of the Cretaceous period, they quickly "disappeared".
Digging small holes and hiding in them from predators, they thus managed not only to protect themselves, but also to wait out the harsh weather. Based on remains found in Australia and Montana, researchers have concluded that Oryctodromeus, whose name translates as "den digging runner", was a true master at digging. The dinosaur had a snout that it probably used as a shovel, strong shoulder muscles, and strong thigh bones with which it burrowed underground. However, even if all this did not help him escape from a suddenly appeared predator, he would use his long, strong hind legs in order to quickly run away from danger.
The hole in which the remains of the dinosaur were found exactly matched its size so that a dangerous predator could not penetrate it. Despite the fact that the length of the dinosaur was about 2 meters (not too impressive), half of this size was taken up by the tail. The fact that the bones of two other young dinosaurs were also found in the burrow indicates that parental care was practiced among these dinosaurs.
6. Spinosaurus (Spinosaurus)
Tyrannosaurus Rex often appears in films about dinosaurs as the most scary predator However, the palm in this case is borne by the Spinosaurus, which is considered the largest carnivore in the world that has ever existed on earth. Weighing 9.9 tons, Spinosaurus, which means "vertebral lizard" in Greek, got its name from the distinctive "fins" on its back, covered with long spines. This imposing 'sail', which could have served as a built-in thermostat, mating bait, or simply to intimidate, reached a height of 2 meters when Spinosaurus arched its back.
Another distinctive feature of this dominant predator of its period was its 2-meter head (the longest among all known meat-eaters) and narrow muzzle full of knife-like teeth. While most other carnivorous dinosaurs had curved teeth, Spinosaurus had straight teeth, possibly for catching slippery prey. Based on the similarities between this prehistoric creature and a crocodile, the spinosaurus probably also grabbed its prey and turned its head in different directions, thereby finishing it off.
5. Sauroposeidon
Although carnivores such as spinosaurs were often viewed as animals whose life was quite difficult, since finding, eating and digesting food for a 60-ton body was not an easy task, 18 meters high and 30 meters long, Sauroposeidon, belonging to the family of carnivorous sauropods , was the tallest terrestrial animal that ever existed. Moreover, the neck alone was 11 meters long.
His physique indicated that he had to consume about a ton of vegetation daily, an almost endless work. To accomplish this "feat", the dinosaur had 52 chisel-like teeth that cut down plants in one fell swoop. He didn't even bother to chew his food, swallowing delicious vegetation, which immediately fell into a 1-ton stomach, the size of a swimming pool. Then his gastric juice, which had incredible strength and could dissolve even iron, did all the rest of the work. The dinosaur also ingested rocks that helped it digest fiber.
It's good that dinosaur worked so well digestive system, because with a lifespan of 100 years (one of the longest in the kingdom of dinosaurs) and in the absence of such a metabolism, he would have grown old very quickly.
4. Deinonychus
This dinosaur got its name for obvious reasons, since it means " terrible claw", and this clearly describes his nature. The bird-like dinosaur was approximately 1.5 meters in height, 3 meters in length and weighed about 91 kg. However, despite its rather modest characteristics, it developed great speed when moving, he was smart and had a good arsenal of defense.
His hind and forelimbs were equipped with razor-sharp, as well as long and curved claws, about 13 cm long. With these claws, he not only grabbed prey with a stranglehold and tore the unfortunate victim to shreds, he also used them when walking. Deinonychus also had an impressive tail, which he used to balance when he stood on one leg, while the other was fighting with the enemy.
As one of the deadliest hunters of its period, Deinonychus was a force to be reckoned with.
3. Triceratops (Triceratops)
If any dinosaur could withstand the wrath of Deinonychus and his ilk, then this is exactly the Triceratops. A large, heavy and horned dinosaur, he was one of the most dangerous animals that lived on land. This species both attacked and defended very well.
The dinosaur had a nose in the form of a horn, and one horn above each eye, up to 1 meter long, thus its weapon, consisting of the strongest materials, could easily gore even the most formidable enemy. As armor, Triceratops used a 2-meter shell that protected the head and neck, which is 6 times thicker than a human skull. However, in addition to defensive characteristics, this shield also served as a body temperature regulator and to lure partners for copulation.
This "steroidal rhinoceros" was half the size of a Tyrannosaurus rex, but weighed the same - about 6 tons. The positioning of the dinosaur's limbs also provided him with significant advantages. In a straight splayed posture, the center of gravity was directed to the head, which was ideal for the strongest frontal attack.
With such an incredibly equipped amount of features, Triceratops was the most common dinosaur of its time.
2 Tyrannosaurus Rex
Most famous dinosaur in the world, Tyrannosaurus Rex has been the dominant predator for 25 million years. Possessing very sharp senses, a bite force of 16 stronger than a bite crocodile and seven tons of pure muscle, this is one of the dinosaurs that definitely lives up to its name, which translates as "lizard tyrant king".
One of the dinosaur's most impressive features was its head. The size of an adult, its head was 2/3 muscle and weighed about 454 kg. The strongest jaw with 50 teeth, each of which was up to a foot long, could easily bite a car. The brain of a Tyrannosaurus Rex was one of the largest in relation to the body of an animal among the entire animal kingdom of the prehistoric period, which was well suited for analyzing information visible to the eyes. By placing the eyes 41 cm apart, Tyrannosaurus rex had excellent binocular vision and could see fine details up to 6 km away. The large olfactory bulbs in the brain of a Tyrannosaurus indicated that its sense of smell was as strong as its eyesight. According to some reports, the strength of his nose was equal to the strength of 1000 bloodhounds.
Contrary to what you may have seen in the movies, Rex couldn't run fast. Based on the ratio of the length of his femur and lower leg, he most likely developed a negligible speed when running. However, with such keen senses, steel jaws and dagger-sharp teeth, did he really need speed?
1. Archeopteryx
Is it a bird or is it a dinosaur? It's... Archeopteryx!
A transitional link between birds and reptiles, this animal has arguably generated more controversy than any other. Moreover, the debate is so heated that until now scientists have not been able to reach a real consensus on its classification. Although its remains, first discovered in 1861, clearly resembled feathers, similar to those of modern birds, they were also strikingly similar to those of small carnivorous dinosaurs found. As a result, today Archeopteryx occupies a worthy place, both among primitive birds and among feathered dinosaurs.
The size of a crow, Archeopteryx had a wingspan of 0.6 meters, however, it also had the characteristics of a dinosaur, which included the presence of sharp teeth, a flat sternum, a bony tail and claws. It is still unclear whether this curious creature used its feathers for flight, temperature regulation, or both. However, the flat sternum indicated that even if they did fly, they did not do so for an extended period of time.
Regardless of his flying prowess, Archeopteryx's status as the first famous bird laid the foundation for our current understanding of how birds evolved.
Any person imagines a dinosaur in the form of a ferocious lizard of terrifying size, baring its huge mouth and destroying everything in its path. Indeed, most of the ancient reptiles were gigantic in size, amazing. This is evidenced by numerous finds of individual fragments and even entire skeletons of fossil pangolins. However, not all dinosaurs were giants; among them there were certain types, which nature, as if in mockery, endowed with the growth of a chicken. These tiny creatures darted in numerous flocks among the thickets of relic ferns, trying not to get under the feet of their huge relatives and looking for even smaller prey.
Why, until recently, scientists knew so little about these amazing crumbs? It was the small stature that played with them bad joke. The bones of these dinosaurs were so light and fragile that they did not stand the test of time and practically did not survive to this day. Only a few finds allowed these small reptiles to make themselves known.
This pangolin has gained fame as the smallest predator of the Jurassic period. Its length did not exceed a meter, and its weight reached only two kilograms. He moved on fast hind legs, had a long tail and a movable head. The nimble dinosaur hunted insects and lizards. In total, three Compsognathus skeletons were found. Two of them were found on the territory of Europe in the middle of the nineteenth and at the end of the twentieth century, and one skeleton was preserved in Russia and was found quite recently, in 2010. Thanks to these findings, scientists were able to restore the appearance and habits of the fossil dinosaur.
Nkvebasaurus
The only fragment of the skeleton of this pangolin was found in 2000 in Africa, near the Sahara desert. Most likely the remains belonged to the cub. The structural features of these lizards include the presence of long fingers, which made it possible to capture prey. The so-called stomach stones, which are usually intended for grinding plant foods, have been preserved in the intestines. This allowed scientists to conclude that the nquebasaurs are omnivores. In length, the dinosaur did not exceed a meter and was a contemporary of Compsognathus.
Scipionyx
The perfectly preserved skeleton of this pangolin was found in Italy at the end of the twentieth century. The skeleton that belonged to a baby dinosaur pleased scientists with an extensive base for research, because the fossilized remains preserved the structure of not only the soft tissues of the animal, but also its internal organs. Most likely, the body of the lizard was covered with primitive feathers. He moved on his hind legs, supporting his body with the help of his tail. The size of adults, according to scientists, reached two meters. The dinosaur lived in the Cretaceous period and was a predator. In any case, scientists found lizards and fish among the undigested food residues.
One of the very first finds that were discovered in England was a fragment of the lower jaw with a pair of huge teeth. It was not difficult to guess that the jaw belonged to one of largest carnivorous dinosaurs. The largest carnivorous dinosaur is called megalosaurus (huge lizard). Unfortunately, no other fragments of the skeleton could be found, which prevented exact definition the true size and shape of the reptile. After some time, various remains of the lizard skeleton were found, but they also failed to draw an accurate picture from them.
Scientists conducted comparative characteristic the largest predatory dinosaur Megalosaurus with others like it, and came to the consensus that the lizard walked on two hind legs, it was about 9 meters long and weighed approximately 1000 kg.
Among the huge variety of dinosaurs, scientists singled out another species, his name is Allosaurus. In the United States, more than 60 different skeletons of reptiles of various sizes were found during excavations, presumably the animals weighed from 1000 to 2000 kg, and were up to 12 meters long.
More large sizes possessed Tyrannosaurus and Tabrosaurus, who lived on Earth more than 80 million years ago, in the Cretaceous period. Their skeletons were found mostly without tails, but presumably it can be stated that their length was up to 15 meters, height up to 5 meters and body weight up to 6 tons.
The skull of Tarbosaurus was 145 cm long, Tyrannosaurus rex - 137 cm. The length of the teeth was more than 15 cm, which allowed the reptile to hold almost any animal actively resisting in its mouth. From such an impressive size and weight, one may wonder, but really the largest carnivorous dinosaurs could they keep up with prey or did they feed mainly on carrion? The front paws of such dinosaurs were very small and weak with two toes.
Tertsinosaurus had a huge finger, its length was 80 cm, but scientists are not sure that everything that was during the life of the reptile was preserved on the skeleton, most likely there were more such fingers.
The spinosaurus, or prickly lizard, had a fin-membrane on its back, 1.8 meters high, which, perhaps, served as a heat exchanger or a tool to scare away rivals and enemies. Oh, these are all trifles, compared with the find in Mongolia. The largest predatory dinosaur was found here. The length of the front small paws was 2.5 meters. Each paw was equipped with three huge claws that could easily kill the victim. Polish researchers dubbed this monster "Deinocheirus", which means "terrible hand".
For comparison, you can take an ostrich dinosaur, which has almost the same structure of the front paws, but several times shorter in length, then we can assume that Deinocheirus was larger than a tyrannosaurus rex one and a half times! Was Deinocheirus the largest carnivorous dinosaur?
During the Cretaceous period, the dinosaurs of South America became, for reasons unknown to science, larger and more ferocious than their counterparts elsewhere. the globe. Giganotosaurus is an eight to ten ton three-toed predator. By the way, its remains were found in close proximity to the remains of Argentinosaurus, one of largest dinosaurs world.. The inevitable conclusion - Giganotosaurus was one of the few theropods capable of destroying the Argentinosaurus! . For more on this scenario, see Giganotosaurus vs. Argentinosaurus - Who Wins?
Utahraptor
Utahraptor was one of the most dangerous predators in the Cretaceous period. Its adults weighed almost a ton. Utahraptors are characterized by such features: single curved claws, outwardly similar
on a medieval sword and a swiss army knife. Oddly enough, this predator giant size lived 50 million years before his more famous descendants, who were much smaller but much faster.
Tyrannosaurus Rex
We will never know if Tyrannosaurus Rex was stronger than giants like Albertosaurus or Alioramus. Was he hunting live prey or most of his time was looking for carrion. In any case, there is no doubt that the T. Rex was just the perfect killing machine when circumstances called for, given its weight of 5 to 8 tons, acute vision and a huge head dotted with numerous sharp teeth. True, his tiny paws - hands from the point of view of a person gave this king of dinosaurs a slightly comical look.
Spinosaurus
Spinosaurus had the same weight class as Giganotosaurus and Tyrannosaurus Rex. The North African Spinosaurus had the added evolutionary advantage of being the world's first identified dinosaur that could swim. This ten-ton predator spent his days near deep-sea rivers and reservoirs, catching fish with massive crocodile-like jaws and occasionally diving like a shark to prey on small dinosaurs.
Majungasaurus
Majungasaurus, once known as Majungatol, has been called a cannibal dinosaur by the press. The discovery of ancient Majungasaurus bones showing bite marks from Majungasaurus teeth is good evidence that these one-colored theropods preyed on their congeners (of course, when they were very hungry, or perhaps they ate their already dead relatives). These predators were much feared by the smaller dinosaurs of their range.
Ankylosaurus
The armored dinosaur Ankylosaurus was a genetic relative of Stegosaurus. These dinosaurs were equally protective of their enemies. Stegosaurus had a spiked sledgehammer at the end of its tail, Ankylosaurus was equipped with a massive 45 kg tail hammer, appearance reminiscent of a medieval mace. The purposeful swinging of such a mace could easily break the hind leg of a hungry Tyrannosaurus Rex or even open the jaws of an enemy. True, there is speculation that Ankylosaurus could also use its tail during intraspecific combat during the mating season.
Allosaurus
Allosaurus was more cruel predator than the much later Tyrannosaurus Rex. Numerous specimens of this ferocious, strong three-ton meat-eater have been found in the western United States. Yes, he was deadly, but not very smart.
Diplodocus
The fact is that this 30-meter huge sauropod had one chip for protection - a seven-meter thin tail, which, according to some paleontologists, he could use like a whip when hitting, and the impact speed was supersonic. Apparently, thanks to this technique, diplodocus kept such a predator as Allosaurus at bay. Of course, Diplodocus (not to mention the Brasiosaurus and Apatosaurus) could simply trample the enemy with their huge flat hind legs. By the way, filmmakers like to show a brighter "tail trick" in their scripts than simple trampling.
Troodon
The feathered dinosaur Troodon weighed only about 68 kg, about the same as an adult human. It is interesting to know that this predator did not have particularly sharp and scary teeth. This theropod, stood out relatively big brain, at least when compared to other carnivorous dinosaurs of the Late Cretaceous of North America. There is an assumption that the Troodon hunted in packs together with their relatives at night (its big eyes well seen in the dark). Troodonts could well compete in their bloodthirstiness with the T. Rex itself!
Theropod dinosaurs are bipedal carnivorous dinosaurs. But it is also a suborder of lizards. They lived in prehistoric times Mesozoic era since the Triassic period. The heyday of their life fell on the Jurassic and Cretaceous period, the latter became the sunset of the life of all dinosaurs.
Predatory "beast" dinosaurs
Theropods differed from all other dinosaurs in that they walked on two legs. The front paws were very small in size, no more than half a meter. Theropods hardly used them. Scientists still can not decide on their purpose.
Among them there were both predatory and
Carnivorous dinosaurs were from huge to very small sizes. The most ancient are found in the Triassic period. Scientists believe that their ancestors were some coelurosaurs from the group of carnosaurs, including tyrannosaurs. It is also believed that the origin of birds originates from theropods.
The oldest predatory dinosaurs include: the record holder for length and weight - Aliwalia (8 meters / 1.5 tons), Staurikosaurus, Coelophysis, Herrerasaurus, Herrerasaurids. The latter appeared at the very beginning of the Triassic period and died out before or at the beginning of the Jurassic period. They were relatively small, only 2-3 meters long and about 80 centimeters high.
Tyrannosaurus rex - a ferocious theropod predator
Tyrannosaurs have existed since the beginning of the Jurassic period. The only well-studied late Cretaceous predator is the Tyrannosaurus rex. Theropod had a nasty bloodthirsty character, sharp teeth and a brutal appetite, as well as a strong body, powerful legs and neck.
A huge head about 1.5 meters long was held on a short neck. In addition, it weighed almost seven tons and was 12-14 meters long. With all his ferocious appearance, he terrified all herbivores, even the largest dinosaurs. In nutrition, he did not disdain anything, even small relatives.
Rex mainly fed on herbivorous dinosaurs, but could take already killed prey from small predators. If he was very hungry, he could eat carrion.
Tyrannosaurus Neighbors
Not only the tyrannosaurus had such a ferocious disposition. Other predatory dinosaurs lived nearby. Here is a description of the predatory dinosaurs that lived next to the tyrannosaurs.
This is a Seratosaurus North America), on the head of which there is a whole ridge of horns. The eight-meter Metriacanthosaurus wore an incredible sail on its back, and liked to eat herbivorous dinosaurs.
Ornitholest - a medium-sized predator - could run on both two and four legs. Megalosaurus - up to nine meters in length, strong, muscular, predator with sharp teeth (remains found in Europe). Dilophosaurus had two bone crests on its head at once, the body length was six meters. He moved quickly and skillfully on two legs.
Allosaurus is another Jurassic nightmare. A bloodthirsty reptile 11 meters long with strong strong hind legs, short three-toed forelimbs with claws and a toothy mouth. He terrified all the inhabitants of the forests where he lived. Some scientists consider it to be the ancestor of Tyrannosaurus Rex.
Another medium-sized (three meters long) formidable killer predator is the "monstrous claw" deinonychus. It had two deadly bladed claws on both hind legs that popped out like spring-loaded bandit knives.
small carnivorous theropods
For example, the dinosaur oviraptor (in translation - a thief), devouring eggs, lived in East Asia. The small dinosaur Troodon (USA) had well developed both hind and forelimbs, with which it could rake leaves and sand poured to hide eggs. He sneaked up to the nest, grabbed the egg and threw it into his mouth, where he pierced it with sharp teeth.
The fastest carnivorous dinosaurs
Fast medium-sized dinosaurs include segisaurs - with lightning-fast movements and the embodiment of speed, with a huge, for their small stature, mouth with sharp teeth, which allows them to quickly swallow small prey.
Another runner is the pokesaur (translated as a swift-footed lizard) - fast as lightning, grabbing darting small prey underfoot. Compsognathus is the smallest, 60 cm long from nose to tail tip, and the height is like that of a medium-sized chicken, but the most ferocious dinosaur.
It was because of such small carnivores that the life of herbivores, especially small cubs, became deadly.
Herbivorous dinosaurs from the Triassic period
The most ancient herbivorous dinosaurs, they are also called prosauropods, lived in Triassic (South America). There were not very large ones, for example, Maszavr, about three meters in length, but the Riohasaurus found in the same place turned out to be much larger and more massive.
The remains of another ancient dinosaur Nyasosaurus was found in Africa, its length was only two meters. The tecontosaurus found in England turned out to be even older. All representatives were similar to each other. They had small heads long necks and tails, short forelimbs are most often five-fingered and with claws. They could not raise their heads high (due to problems with cervical vertebrae), they had to collect leaves (as food) from the ground or be content with shoots and twigs that grew lower.
Herbivorous theropods of the Jurassic and Cretaceous periods
Descendants from the Jurassic and Cretaceous periods were called "Ornithischian", they were very different in their huge size from their ancestors. They became larger, more massive, there were three fingers on the front paws, instead of five.
None of the animals living on earth could and cannot be compared with herbivorous dinosaurs. By creating them, nature has surpassed itself.
Apatosaurus (brontosaurs), diplodocus and brachiosaurus are real champions in height and weight. This large group dinosaurs were called "sauropods".
- The most massive was the Brachiosaurus, its weight was about 50 tons.
- The longest-necked is Mamenchisaurus, its neck was about 15 meters long.
- The longest tail has grown in diplodocus - as much as 12 meters.
- Shanosaurus turned out to have the most unusual tail, a bone outgrowth in the form of a mace grew at its end.
- Those who had not very long necks: Camarasaurus, Vulcanodon, Ouranosaurus with its magnificent sail on its back, which served to cool.
Relatively small dinosaurs: Iguanodon, Psittacosaurus and Protoceraptos with their beaks did not suffer much from a lack of food. Vegetation in jurassic there was enough for everyone, because trees and shrubs grew in abundance.
Caring mothers and their offspring
Dinosaurs, like most modern reptiles, laid eggs. This is confirmed by many finds of fossilized ovipositions, they differed in size and laying. In some dinosaurs, the eggs were laid in a circle, in others in a spiral, in others in a line. Interesting fact: in the entire history of excavations, archaeologists have never found eggs of a tyrannosaurus rex.
Having arranged a nest in an earthen hole, the female laid eggs there, then covered them with leaves and small debris on top so that predators would not notice. Some dinosaurs piled dry twigs and leaves on top not only for protection, but also to maintain a certain temperature.
Mothers did not leave the nest with eggs for a long time, they were constantly nearby to save the cubs from the attacks of various predators. They left only to eat and drink. Scientists concluded that the sex of future dinosaur babies depended on the temperature in the nest. But in any case, there were almost always more "girls" than "boys".
At first, newborn cubs stayed close to their mothers until they became large and strong enough to be able to get their own food and run away or defend themselves from enemies.