Clawed dinosaur. Dinosaur: Deinonychus "Terrible Claw"
The largest representative of his squad is rightfully considered its main symbol. The dinosaur had a strange barrel-shaped body and at the same time managed to move on two short legs. Latin name comes from a pair of ancient Greek words - mower lizard. It is directly related to the long claws on his upper limbs, shaped like curved daggers.
Business card
Time and place of existence
Therizinosaurs existed at the end of the Cretaceous period, about 71 - 69 million years ago (the beginning of the Maastrichtian stage). They were distributed in the territory of modern Mongolia, in the Gobi Desert.
This is how Argentine paleoartist Gabriel Lio imagines the dinosaur.
Types and history of discovery
Nowadays the only known species is Therizinosaurus cheloniformis, which is accordingly typical.The first remains of Therizinosaurus were discovered during a Soviet-Mongolian expedition to the Nemegt Formation (Umnegovi aimag, Mongolia) in 1948. They included several giant claws, which, taking into account the supposed cornea, reached a meter in length. The fossils were described by Russian paleontologist Evgeniy Maleev in 1954. He initially classified the therizinosaur genus as swimming turtles that reached as much as 4.5 meters in length. According to him, ancient reptiles used such impressive claws to collect their main food - algae. This historical fact is not at all surprising, since the available remains were extremely scarce, and therizinosaurids were not known at that time. The holotype specimen, which consists of claws, is labeled PIN 551-483.
At the beginning of the article, we explained the generic name of Therizinosaurus. The specific name cheloniformis is translated from Latin as “shaped in the image of a turtle.” It is not difficult to guess that this is connected with the above-mentioned assumption of Maleev.
The claws could belong to any order of reptiles and the question remained open until 1970. It was then that another Soviet paleontologist, Anatoly Konstantinovich Rozhdestvensky, identified a dinosaur close to theropods in the fossil remains. However, the appearance of Therizinosaurus continued to remain a mystery. This gave rise to unusual speculations in which the dinosaur was presented as a large predator, such as Giganotosaurus, but also had giant claws on its feet, like Deinonychus. And, like the latter, therizinosaurus used them as weapons when hunting.
Subsequent expeditions lifted the veil a little. In 1976, Mongolian paleontologist Rinchengiin Barsbold described specimen IGM 100/15-17, which was a set of claws and parts of the forelimbs of a therizinosaur. Then in 1982, his colleague and compatriot Altangereliin Perle described specimen IGM 100/45, consisting of hind limb bones.
Then follow the most important discoveries of close relatives, which finally made it possible to restore a fairly complete skeletal image of therizinosaur.
A group of females led by a brightly colored male by Spanish designer José Antonio Penas.
But at the same time, questions of origin still remained open for some time. Due to their external resemblance to prosauropods, it has been suggested that they are the direct ancestors of therizinosaurids. However, the discovery of the Chinese Beipiaosaurus and Alshasaurus, and then the ancient Phalkarius, proved the theory of origin from theropods.
Body structure
The body length of the therizinosaur reached 10 meters. The height is up to 5 meters. It weighed up to 5 tons. He was the biggest of them all famous representatives squad.
As is known, most bipedal dinosaurs were digitigrade, that is, they relied on the bones of their fingers when moving. However, now there is more and more evidence in favor of the fact that therizinosaurus was a plantigrade animal, that is, when moving, it relied on its formed foot. Firstly, this assumption is supported by the shape of therizinosaurid tracks, a detailed analysis of which is presented in the work of Russian paleontologist Andrei Gerasimovich Sennikov, “Reading the tracks of segnosaurs.”
Here is a skeletal reconstruction of Therizinosaurus from this work, showing the position of the bones when walking. Computer processing by Andrea Kau.
Secondly, this is evidenced by a number of anatomical features: The complex model is radically different from the model of classical bipedal dinosaurs. Therizinosaurus's tail was very short and could not serve as a serious balancing tool. At the same time, the body was high and ended long neck. Therefore, the structure becomes even less stable. The wide foot really makes the Therizinosaurus model more viable.
Forelegs with giant claws
Therizinosaurus had rather long and strong forelimbs (up to 3.5 m), on which there were three fingers. Each finger was equipped with a long sharp claw, reaching a length of 1 m. The latter was flat and slightly curved, thereby resembling the blade of a scythe. The photo shows reconstructed fingers from the collection of the Aatal Dinosaur Museum (a suburb of Zurich, Switzerland).
This strange adaptation of therizinosaurs has no analogues in the modern animal world, so it still remains a prehistoric mystery. What assumptions do you currently have?
The first version talks about intraspecific competition and determining the place in the general hierarchy depending on the size and shape of the therizinosaur’s claws. Here we will add attracting a partner to mating season through unusual dances, screams and simultaneous waving of long limbs with claws.
The second version is a tool for obtaining food. With its claws, therizinosaurus could cut off the soft stems of some plants, and also extract edible roots from the ground that were at a shallow depth.
The third version has primarily defensive functions: the claws helped the therizinosaur protect itself and its offspring from groups of relatively small predators.
In our opinion, the version of a universal instrument is the most justified, that is, several of the listed points could have taken place at once. Here we can draw a parallel with the graceful antlers of deer. Most likely, the claws grew throughout life, that is, even a break at the base was not a problem for the therizinosaur.
Other aspects
Even though the skull of Therizinosaurus has not yet been discovered, it can be said with reasonable confidence that it was similar to the skulls of its closest relatives. That is, small and elongated, with a set of small teeth. The body was large and barrel-shaped.Although most modern paleoartists depict Therizinosaurus as feathered, this is nothing more than speculation.
American artist Todd Marshall offers us an elegant version of feathers. It is based only on the confirmed plumage of some early therizinosaurids. So far, there is no physical evidence specifically for Therizinosaurus.
The stiff tail was very short. Overall, the adult Therizinosaurus was a massive bipedal animal. He led a measured lifestyle, somewhat reminiscent of a giant ground sloth.
Therizinosaurus skeleton
The photo shows the upper limbs of the species Therizinosaurus cheloniformis from the Experimentarium Museum (Copenhagen, Denmark).
Below is another rough reconstruction of the skeleton.
Nutrition and lifestyle
To date, the head of Therizinosaurus has not been found. However, as was said in the previous section, it was most likely similar to the heads of close relatives. Consequently, the jaws were equipped with small, straight teeth suitable for plucking soft elements of vegetation. This could include foliage, young needles and branches, as well as ripe fruits. With strong paws, therizinosaurus was able to bend young trees and thereby reach the tops of the crowns. With its claws, it could also extract suitable tubers and roots from the damp soil, although they are unlikely to form the basis of its diet.In the literature one can find suggestions that therizinosaur was able to destroy anthills or termite mounds with its claws and eat their inhabitants, like anteaters. However, it is unfounded, because such food would not be enough for five-ton adult therizinosaurs even for partial saturation. For example, a giant anteater weighs only 41 kilograms. Anteaters do have long claws, but they are much thicker and curved. That is, they are more adapted for regular digging without the risk of serious damage. At the same time, the modern anteater has a lot of unique skeletal details that allow it to occupy this niche. Nothing similar is observed in therizinosaurus, so the version is quickly dismissed.
Despite the colossal size of the “mower lizards,” they had in the flourishing Nemegt formation natural enemies- Tarbosaurs. Adult representatives of these posed a threat to any herbivorous individual. After all, the long thin claws of the therizinosaur posed very little danger to their thick skin. The only hope left was for the effect of intimidation and a strong blow with developed limbs.
But the claws, coupled with the latter, could be quite effective against small predators.
Baryonyx
It's no surprise that this British dinosaur was nicknamed "clawed". The huge claws that grew on the fingers of its forelimbs were almost as long as human hand!
For the first time, the remains of Baryonyx were found next to the fossilized bones of Iguanodon, another dinosaur with opposable claws. Examining the skeleton of Baryonyx, which experts assembled from scattered pieces, we can confidently identify a number of characteristic features. Such features include, for example, an oblong skull sitting on a long neck.
The body of Baryonyx was the length of a bus - about 9 meters, and weighed accordingly - approximately 2 tons. For comparison, we note that this weight is equal to the total weight of twenty-five adult men of average height and stature.
| Name | Class | Superorder | Squad | Suborder |
| Baryonyx | Reptiles | Dinosaurs | Lizard-pelvic | Theropods |
| Family | Height/Length/Weight | What did you eat? | Where did you live? | When he lived |
| Spinosaurids | 2.7 m /8-10 m/ 2 t | fish | Europe | Cretaceous period (130-125 million years ago) |
Eating fish
The hind legs of Baryonyx were very powerful, although the forelimbs were almost as strong as them. Some scientists even believe that Baryonyx could walk on four legs, wandering along the river bank and looking for fish.
Imagine a scene like the one below. Such scenes could well have played out some 120 million years ago on that part of the earth's landmass that is now called England. It was the early Cretaceous period, and lush greenery grew along the banks of numerous rivers and lakes.
The carnivorous lizard Baryonyx could easily find food for itself in the form of many small living creatures. However, there is evidence that he obtained food in such an unusual way for a dinosaur as fishing, as can be seen in the picture.
A huge claw on the opposite blubber could be very useful for fishing. Scientists learned that Baryonyx ate fish by finding fish fossils in its remains.
Tooth and claw
Another feature of Baryonyx is the double (compared to other carnivorous lizards) number of teeth in its long crocodile-like jaws. The largest teeth were located in the front cavity of the mouth; as they moved towards the back, the size of the teeth decreased.
The teeth were conical and slightly serrated—an ideal shape for grasping slippery, squirming prey such as fish or a small dinosaur such as Hypsilophodon or even a juvenile Iguanodon.
Scientists have concluded that Baryonyx has claws on the hind limbs that are not as huge as those on the front. Baryonyx was too heavy to stand on one hind leg and use the other claw to strike an opponent, as a much smaller and lighter dinosaur like Deinonychus could easily do.
Yet the forelimbs of Baryonyx were powerful enough to carry such formidable weapon. It probably wasn't easy sea fish, even the most nimble ones, when Baryonyx went hunting!
Deinonychus or Deinonychus is a predatory dinosaur of the theropod suborder. The species name comes from the Latin word Deinonychus, meaning "terrible claw".
Species: Deinonychus "Terrible Claw"
This amazing dinosaur was first discovered in 1963 in North America in sediments dating back to the mid-Cretaceous period. Having a height of 1.5 meters and a length of 3-4 meters, this animal could not be classified as a giant of its time. Moreover, the length of the tail was half the entire length of the animal. This tail was rigid at the back and supported the stability of the body when running. Deinonychus ran parallel to the surface of the earth.
The same tail, flexible at the base, helped the animal quickly change the direction of its run. Deinonychus used it as a steering wheel and this made it possible to quickly change the direction of movement, preventing the victim from escaping. The hind limbs had one large curved claw. While pursuing prey, the animal could take it upward.
Was very dangerous predator, although its size was small. The lizard's body was ideally suited for bloody hunting. Its jaws were equipped with sharp teeth.
But his most important weapon was his large and sharp claws, both on his front and hind legs. If the victim was overtaken by Deinonychus, she was doomed to death. The predator quickly, with all its strength, plunged all its claws into the body of the victim. And then, tenaciously holding the unfortunate animal with its forelimbs with sharp claws curved down, Deinonychus beat the victim with his strong hind paws and at the same time dug into it with his jaws and chewed out pieces of prey.
The death grip of the predator's jaws was ensured by the structure of its skull: the lower jaw was attached to the back of the head, while it could open its mouth wide. Plus, Deinonychus’s teeth were located at an angle inside the jaw and there was no way for the victim to free himself from his grip. Even if the unfortunate creature resisted furiously, with each movement the predator's teeth pierced deeper and deeper.
Polish paleontologists came up with the name “Deinonychus,” which means “terrible claw,” for good reason. The reason was the sickle-shaped claw of the second finger, which grew up to 13 cm in length. It was pointed upward and the predator was ready to use it at any moment.
Who were the victims of Deinonychus? Apparently, these were babies and young dinosaurs of a wide variety of species. But most often these were herbivorous lizards, for example, gypsylophodon.
results archaeological excavations always interesting, and often unpredictable. However, sometimes surprise reaches such a limit that one involuntarily thinks: apparently, nature itself mocked these creatures... Some fossil prehistoric animals had very strange looking, equipped with such “devices” as vaulted skulls or crescent-shaped toenails. NationalGeographic magazine presented a ranking of the most bizarre dinosaurs that once lived on planet Earth.
1. Amargasaurus
Outstanding Feature: Double row of spines along the neck and back
Period of residence: 130-125 million years ago
Found: in Argentina
This diplodocid had a very interesting feature: a row of spines up to 65 cm in length each, located on the back and neck. They could form a spiky mane or be covered with skin, creating a structure like a double sail. Whatever form they took, it was a very unusual adaptation, and probably played a role in the animal's social life or was used for defense - a valuable asset for an animal that was almost half the length of its relatives.
Amargasaurus had a thin whip-like tail and blunt teeth adapted for tearing leaves from branches. Like other sauropods, it probably swallowed stones, or gastroliths, to aid digestion. With its spiny spine, Amargasaurus resembled a dicraeosaur, and some paleontologists classify the two species as a separate family.
2. Carnotaurus
Outstanding Feature: Strong legs and small front paws
Period of residence: 82-67 million years ago
Found: in Argentina
The carnotaurus's well-developed front legs give the impression that the beast was conceived as a perfect killing machine, but at the final stage some details were missing. However, the predatory happiness is not in the front legs - the Carnotaurus instilled fear in other dinosaurs with its strong jaws and long and fast hind limbs. Carnosaurus exhibits features similar to dinosaurs of the Northern Hemisphere, such as the sharp, thin, crooked teeth characteristic of carnivorous therapods.
Its forelimbs were very short, like those of tyrannosaurs. North America and Asia. However, the carnosaurus also had individual characteristics: it had a horn. The horns were bony outgrowths in the upper part of the skull, directed to the side and upward. During life, they were apparently covered with a horny membrane, like the horns of modern bulls or bulls.
The horns of the carnosaurus most likely played the role of identification marks, but since only a few skeletons of these dinosaurs have been found, it remains unclear whether only males or females had horns. The carnosaurus's muzzle was very narrow, but below the horns the skull widened sharply, so that the eyes were shifted slightly to the side. Thanks to this, the carnosaurus could have binocular vision, when the visual fields of the left and right vision intersect. Humans also have the same type of vision. An animal with such vision can accurately determine distance, which makes it excellent hunter: Carnosaurs looked out for their prey and caught it with dexterity.
3. Parasaurolophus
Outstanding Feature: Tube Shaped Comb
Period of residence: 76 million years ago
Discovered: North America
Parasaurolophus is the most remarkable representative of the hollow-crested duck-billed dinosaurs. The nasal bones of his skull turned into giant, long hollow tubes that curved and stretched behind his head. Why were such educations needed? Paleontologists don't yet know for sure, but they believe that these were some kind of voice amplifiers, similar to the nasal folds on the heads of hadrosaurs without crests. With such an “instrument” the animal could make sounds like a trombone in order to attract females or challenge rivals to a duel.
According to another point of view, such pipes created air circulation in the skull and cooled the brain in the heat. The luxurious crest of the parasaurolophus could have another function: to work as a kind of reflector of branches whipping on the face when the lizard made its way through the forest thicket - note that the crest fits exactly into the notch of the spine, while the shape of the body becomes streamlined. It is quite possible that all these hypotheses are correct and the ridge was a multifunctional structure. And if it had a signaling function, then the animal’s tail probably performed the same duties. The tail was wide, flattened on the sides, and very much resembled a board. It appears that large areas of the skin on the sides of the tail were brightly colored. With its help, parasaurolophus also probably challenged the enemy to a fight, or gave signs.
4. Masiakasaurus
Outstanding Feature: Amazing Teeth
Period of residence: 70-65 million years ago
Found: Madagascar
The fossilized remains of the jaw of Masiakasaurus, a dinosaur the size of a German shepherd, were found in Madagascar in 2001. Translated from the local dialect, the name of the dinosaur is translated as “irregular lizard.”
The main feature of Masiakasaurus is not its small sizes, but in specific teeth. The first tooth of the lower jaw protrudes forward at an angle of 90˚. Other teeth are straightened and positioned vertically. The teeth themselves are also unique: in the back of the jaw they are flattened and jagged, the front ones are long, almost conical, with spiny ends and tiny notches. This indicates a special way of obtaining food: Masiakasaurus caught up with the victim, wounded it with its front teeth, and chewed it with its back teeth.
5. Tuojiangosaurus
Standout Feature: Shoulder spines
Period of residence: 161-155 million years ago
Discovered: in China
IN best traditions The Jurassic-era bulky Tuojiangosaurus has a long, spiny tail and spine-like plates along its back. But this dinosaur is unique, the remains of which were found in the mid-twentieth century in China, thanks to the sharp conical spines that “decorate” its shoulders. Scientists have differing opinions about the function of spines. One version: the spines protected the body of Tuodzhiangosaurus from attacks by Alosaurus or other predators.
6. Deinocheirus
Standout Feature: Giant Paws
Period of residence: 70 million years ago
Found: in Mongolia
Deinocheirus (translated from Greek as “terrible hand”) is a theropod, a predatory dinosaur. Anatomically, Deinocherus was probably similar to a modern ostrich, but scientists do not know for certain what the body of this predator with huge arms looked like. Each of the found paws of Deinocheirus extends 2.4 m. This anatomy was especially useful during hunting. It is assumed that, thanks to its clawed paws, Deinocheirus could climb trees.
7. Dracorex
Outstanding Feature: Pointed Head
Period of residence: 67-65 million years ago
Discovered: North America
"Dracorex" is Latin for "king of dragons." His skull, covered with spikes and sharp projections, truly has a royally menacing appearance. However, its owner himself most likely resembled not a fire-breathing monster, but a wild pig.
8. Epidendrosaurus
Outstanding Feature: Extra Long Finger
Period of residence: 160 million years ago
Discovered: in China
The title of smallest among the most bizarre dinosaurs belongs to the tiny Epidendrosaurus, a sparrow-sized theropod. However, this little creature had prominent forelimbs. Epidendrosaurus was described in 2002 by paleontologists from the Chinese Academy of Sciences. It is the smallest dinosaur known to science, although scientists cannot say for sure whether the bone imprints on the stone belong to a juvenile or an adult. But the object of greatest interest to experts is the function of the limbs of Epidendrosaurus. According to a common version, Epidendrosaurus used its long fingers to search for insect larvae in trees.
9. Styracosaurus
Standout Feature: Horned Collar
Period of residence: 75 million years ago
Discovered: North America
Styracosaurus is a herbivorous dinosaur that makes it into this ranking thanks to its amazing collar. The Styracosaurus's collar is decorated with six long, pointed spines. In addition, the dinosaur is armed with a 60 cm long horn. Such an animal is not afraid of any predators.
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Material from NationalGeographic supplemented with materials and illustrations from dinopedia.ru
Materials used: http://anastgal.livejournal.com/1390092.html#cutid1
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A pack of ceratosaurs attacks a stegosaurus At the end Jurassic period North America was inhabited by dinosaurs of a very formidable species - stegosaurs (Stegosaurus). Living side by side with large predators, they had several levels of protection: their body size was comparable to a bus, and along the ridge from the very neck stretched two rows of spatulate plates, turning into four bone spikes on the tail. But with such a terrifying appearance, they were very clumsy and represented a tasty morsel for the most dangerous hunters of its time - ceratosaurs (Ceratosaurus). True, no predator would have dared to cope with such a giant alone, so ceratosaurs preferred to attack in a pack. It is unlikely that the hunt was easy and fast; most likely, some of the attackers died from the blow of the stegosaurus’s tail, but if successful, the rest got more meat. |
Attack is a common strategy in the animal world. Its motives are varied: they attack for food, possession of a female, while protecting cubs or a nest. Dinosaurs were no exception; on the contrary, they became one of the most striking examples of such behavior, invented, by the way, by completely different creatures and long before them - approximately 570 million years ago. It was then that organisms that fed on animal foods instead of eating dead organic matter or algae became widespread on Earth. In other words - predators. And even then, means of hunting (various articulated appendages, spines, “harpoons”, poisonous glands) and means of protection (shells, shells) arose. With the advent of new life forms, adaptations for attack and defense naturally changed; their original modifications also appeared in dinosaurs: curved claws and teeth in several rows, huge horns, collars and shells. Although by their nature all these wonderful devices are nothing more than modified skin or skull bones. After the dinosaurs, some reptiles and mammals also tried to arm themselves and defend themselves in a similar way, but they were all far from the dinosaurs of the Mesozoic. Now on Earth only turtles and crocodiles are content with a modest share of the terrifying equipment that dinosaurs owned.
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Tarbosaurus stalks an ankylosaur An Asian relative of the Tyrannosaurus, Tarbosaurus was one of the largest predators of its time and occupied the top step in the food chain. The five-meter lizard moved on two muscular legs and could catch up with any herbivorous dinosaur. Most of its huge head was made up of a mouth lined with 64 dagger-shaped teeth. Such teeth entered the flesh like sharp curved spears, and, coming out, tore it with their jagged edges. But did this “king of beasts” dare to attack Tarchia? After all, the latter was an armored monster from the ankylosaurid family and had only one unprotected place - its belly, which could only be reached by turning the Pinacosaurus over, while avoiding the blow of its tail club. Such an attack is too risky even for a Tarbosaurus - maybe it would be easier to look for smaller prey or take a piece of carrion from someone? In the foreground: the height of a fight between a velociraptor (he is below) and a protoceratops. |
Deadly weapon
Predators are those animals that kill their own kind for food. This action requires special behavioral qualities and external fixtures, which allow you to track, catch up with and attack prey. Among dinosaurs, animal-footed lizards - theropods - hunted for predation. Dinosaurs of this group walked on two legs, but their forelimbs were reduced to small appendages. The hind legs, equipped with powerful muscles, allowed the animals to develop decent speed. According to calculations, the tyrannosaurus - the most studied predator - could move at a speed of 30 km/h, which is quite a lot for a 7-ton creature. But, of course, this figure is much lower than the speed of modern large predators, for example a tiger, sometimes reaching 80 km/h. Small and agile dinosaurs won in terms of speed. It is estimated that the 3-kilogram Compsognathus (lived in Europe 150 million years ago) could run with maximum speed 64 km/h.
Since the front legs of predatory dinosaurs were practically non-functional, their main weapon of attack was their teeth. They actually reached terrifying sizes and shapes in some theropods. A typical example is the mouth of a tyrannosaurus, studded with six dozen sharp teeth of different sizes, among which 30-centimeter “daggers” stood out. All the teeth had a sawtooth cut along the back edge and curved back, which made it possible to hold the victim and tear it to pieces. Scientists are finding T. rex bite marks on the bones of other animals. For example, about 80 marks are present on the pelvic bones of the herbivorous Triceratops, which clearly indicates its murder. When studying one of the tyrannosaurs, bite marks were found on its cranial bones, and in its cervical vertebra- a tooth that belonged to a representative of the same species. Does this indicate a fight between two tyrannosaurs? Yes, they could have mated over food or a female. Although the latter is unlikely, since it presupposes the presence of developed sexual behavior, and dinosaurs are unlikely to have such behavior. Rather, it can be assumed that tyrannosaurs practiced cannibalism during the hungry season.
Allosaurus, which lived before Tyrannosaurus rex, could have hunted giant Diplodocus and Apatosaurus. This is confirmed by those found in American state Wyoming tail vertebrae of the Apatosaurus with deep marks from the teeth of the Allosaurus, and one 15-centimeter tooth of the Allosaurus, just like in the previous example, was completely stuck in the tail of the enemy. Apparently, he was knocked out in a fight between lizards.
Another terrible weapon of attack - sharp saber-shaped claws did not appear in small predatory dinosaurs immediately, but only in Cretaceous period(145-65 million years ago). A small dinosaur, Baryonyx, a “heavy claw” that lived in what is now England 130 million years ago, had a sickle-shaped claw on its front paws. Velociraptor, a “swift-footed hunter” a little less than two meters long, was armed with claws on its hind legs, one on each. A similar 3-meter-long Deinonychus, the “terrible claw,” had in its arsenal three sharp claws on its front paws and one saber-shaped claw 13 centimeters long on its hind paws. This long claw was mobile and leaned back while running. Deinonychus hunted young herbivorous dinosaurs like hypsilophodon and iguanodon; they caught up with the victim, jumped onto its back with a running start or clung to its side, immediately plunging its saber-shaped claw into the victim’s belly.
The details of how exactly carnivorous dinosaurs used teeth and claws, and the list of their victims, are mainly theoretical generalizations, but there is very little direct evidence (that is, finds), and even those allow different interpretations. Like, for example, the most famous discovery of two skeletons of mated lizards - the herbivorous Protoceratops and the predatory Velociraptor, made in 1971 in the Gobi Desert by scientists of the Soviet-Mongolian paleontological expedition. It would seem that everything is obvious: both dinosaurs received heavy injuries in the fight, and they did not have the strength to open their jaws and run away when the dust storm began. And so the opponents died in each other’s arms. However, in paleontology, the same fact can often be interpreted in different ways. No, there was no fight, say opponents, but simply a seething water stream that bizarrely connected two dead animals and buried them entangled under a layer of sand and silt.
Bodily adaptations, such as teeth or claws, certainly served as the main tools of a predator, but they were powerless against animals of comparable size. To cope with large dinosaurs, which also grazed in herds, additional techniques were needed. Researchers believe that for the sake of efficiency, some predators may have mastered collective hunting, as lions and wolves do. True, hunting in a pack has both pros and cons: on the one hand, it is easier to deal with the prey, on the other, each hunter gets less food. There is evidence of a group attack even among large dinosaurs: For example, the bones of seven mapusaurs found during excavations in Argentina lay nearby. The researchers found that these dinosaurs died at the same time and may have been members of a pack that hunted together. Technically, there is nothing incredible about the fact that several mapusaurs felled a 40-meter Argentinosaurus. Similar collective burials are known for Coelophysis. It is believed that two or three of them hunted giganotosaurs. Although, on the other hand, the discovery of several skeletons of predators that died at the same time only indirectly indicates that this is a pack. The general location of their death may be explained by another fact, for example, animals exhausted by the heat came to a dry watering hole.
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Battle between Styracosaurus and Tyrannosaurus The debate continues about whether the Tyrannosaurus was a true predator or a carrion eater. Even if the last assumption is true, then real life reptiles, of course, there were fights with individuals of comparable sizes. The tyrannosaurus, being very hungry, could attack the first prey it came across, including a sick but still quite strong animal that had strayed from the herd. At the same time, the enemy did not necessarily find himself defenseless against the teeth of a predator, but could easily stand up for himself, as, for example, Styracosaurus - a ceratopsian with a half-meter horn on the muzzle and sharp spines around the cervical collar. How exactly the battle between these dinosaurs might have gone and who would have emerged victorious, one can only guess. Tyrannosaurus rex bites would have left monstrous lacerations on the Styracosaurus's body, and it could have weakened over time, bleeding to death. At the same time, the predator also had its Achilles heel - its belly, open to the sharp horn of the enemy. |
Intelligence is the main weapon of a predator
It is not enough to have teeth and claws, you also need to use them skillfully, and this is impossible without intelligence. After all, the hunter’s lifestyle presupposes the need to actively move in order to track and pursue the prey, and to anticipate its maneuvers. So the intelligence and sensory organs of predatory lizards were more developed than those of those who led a peaceful existence. And the higher the intelligence, the larger size brain, and dinosaurs were no exception to this rule. Fossil skulls show that the brains of theropods were clearly larger in volume than the brains of sauropods - gigantic herbivorous dinosaurs with a long neck and small head. Big brain Velociraptor and Deinonychus possessed, and the absolute champion in brain volume was Stenonichosaurus: its brain was six times larger than that of a modern reptile of the corresponding size. In addition, stenonychosaurs had very large eyes and presumably binocular vision, like birds and humans. With this type of vision, the animal does not see a separate picture with each eye, but the area of intersection of images received from both eyes. This allows him to move precisely towards the intended target. Undoubtedly, such an ability - innovative for the fauna of that time - helped Stenonychosaurus more effectively pursue prey. Modern technologies allowed us to draw some conclusions about the sensory organs of predatory dinosaurs. Sergei Savelyev from the Institute of Human Morphology of the Russian Academy of Medical Sciences and Vladimir Alifanov from the Paleontological Institute of the Russian Academy of Sciences made a silicone cast of the brain from the brain cavity of Tarbosaurus, using its entire skull, and compared it with the brain of birds and modern reptiles. It turned out that Tarbosaurus had large olfactory bulbs, well-developed olfactory tracts, and good hearing. But with the visual system everything turned out to be different - it was not so developed. It turns out that Tarbosaurus relied more on smell than on sight in search of prey. Why did he need this? Most likely in order to smell the smell of rotting meat from afar. Probably, Tarbosaurus, and by analogy with it, other large predatory dinosaurs did not lead a completely predatory lifestyle - they did not neglect to feed on carrion. To confirm this conclusion, scientists also pay attention to the enormous size of the lizards - such giants as Tarbosaurus and Tyrannosaurus could not always feed themselves by hunting; most likely they had to be content with what they found under their feet. There is a kind of compromise version of predation: the animal hunts under a successful combination of circumstances, for example, when the prey is very close and you can quickly run up to it to grab it; when she is sick and cannot escape, or the victim is a cub. In addition to these trade-offs, the predator ate more accessible food, the search for which did not require large expenditures of energy.
The armor is strong
The prey for which predatory dinosaurs “sharpened” their dagger teeth was a very diverse sight: all kinds of herbivorous species, as well as those animals that ate fish, did not disdain lizards and arthropods. Currently, the division of dinosaurs into carnivores and herbivores is generally quite arbitrary; most of them should rather be considered omnivores. The difference between active and passive animals is much more clearly expressed, because it was the latter that most often became the prey of the former. Dinosaurs that led a passive lifestyle, that is, did not know how to run and hunt, were probably the most amazing creatures who have ever lived on Earth. Many of them were simply overwhelming with their size. For example, the gigantic sauropods - Diplodocus, Brachiosaurus, Brontosaurus - reached 40 meters in length and weighed tens of tons. It’s not at all easy to kill them; not a single predator of that time could compare with them in size. It turns out that the very size of the body of sauropods served them as a kind of protection. Allosaurus and ceratosaurs that lived alongside diplodocus were unlikely to hunt adults alone. Most likely, predators followed the herd and waited for an old individual or a cub to break away from it. It was only possible to kill an adult diplodocus or brontosaurus through the efforts of several large predators.
Representatives of ornithischian dinosaurs - stegosaurs, ankylosaurs, horned dinosaurs were not as huge as sauropods, but very unusual in appearance. Their spikes, horns, protrusions and shells looked like powerful protective armor. For example, stegosaurs had bony plates on their backs that extended from the vertebrae. On the back of himself known species, the stegosaurus itself, there were bone plates alternately arranged in two rows, which looked very impressive. But did they provide protection from the teeth of a predator? Most scientists believe that the plates are unreliable as a means of protection: they were easy to break and left the sides of the reptile exposed. Most likely, the plates served for thermoregulation of the individual: the skin covering them was probably penetrated by a rich network of blood vessels, which allowed the lizard to warm up faster in the morning sun and begin to move when the predators were still sleeping. But recent studies cast doubt on this version: if there were blood vessels there, they were located in such a way that they could not effectively remove excess heat. It is possible that the dorsal plates served as species identification marks, like the bright colors of the plumage of birds, but this is not entirely certain. Why, for example, does one of the stegosaurs, the “spiny lizard” Kentrosaurus, found in Africa, have narrow and sharp plates on its back and a long spike on its sides on each side? In addition, stegosaurs had four powerful spines on their tail, which they could easily use to fend off attacks from predators.
The ankylosaurs that colonized vast territories were dressed in real protective armor. ancient earth- from North America to Antarctica. Their bodies were completely covered with shells made of ring-shaped bone shields encircling their backs, which provided passive protection. In some species, the shields grew together, like in turtles. The shields on the carapace of the ankylosaur (Ankylosaurus) were completely covered with bumps and spines, so that the lizard looked like a huge lump. Such protection had its costs: the armored animals were clumsy and slow, moving at a speed of no more than 3 km/h. Did the shell reliably protect them from predators? Probably yes. The ankylosaur became vulnerable only if it turned upside down with its belly devoid of shell. But even a large hunter was unable to do this to him. In addition, the ankylosaur was able to actively defend itself with its tail and a heavy bone mace, delivering powerful blows to the enemy with it.
Herbivorous lizards from the ceratopsian group, squat four-legged animals with a large head, acquired a horn on their muzzle. Their skeletons with impressive bony horns protruding directly from the skull were first discovered back in 1872, and subsequent discoveries showed that at the end of the era of dinosaurs, “horned lizards” reached great diversity. On their necks, ceratopsians wore a bone “collar” made of fused skull bones, and the end of their muzzle looked like a beak. North American horned lizards, Triceratops, wore three horns: one on the nose, like a rhinoceros, and two, meter long, sticking out above the eyes. Like modern horned animals (deer, rhinoceroses), the horns of dinosaurs played a primary role in sexual selection: those with more horns conquered the best females and received more viable offspring. In addition, Triceratops could actively defend themselves from predators with their horns: threaten, wave them off, hit the enemy from below, ripping open their belly, which, by the way, was open in bipedal theropods. Depending on the situation, the horns may have been used as an attack weapon - to clarify the relationship between rivals of the same species, for example, during mating fights.
The bony collars of ceratopsians also most likely served as a sign of external distinction, like the tail feathers of a peacock. In addition, strong masticatory muscles jaws. But still, the collars could protect the neck, although not completely, since many species of dinosaurs had holes in them. The Torosaurus skull, including the collar, reached a record size of 2.6 meters, and it had several large “windows”. On the contrary, the Styracosaurus found in Canada had a complete collar and was equipped with six long, sharp spines. Paleontologists believe that this good protection scared away predators from encounters with styracosaurs.
In November 2007, Canadian paleontologists unearthed the world's largest horned dinosaur, 9.75 meters long, in Horseshoe Canyon in Alberta, Canada. It was identified as the ancestor of Triceratops and named Eotriceratops xerinsularis. The length of the Eotriceratops skull was about three meters, almost like a car. The expedition members lifted it up the slope with great difficulty. Like Triceratops, Eotriceratops was armed with two one-and-a-half-meter-long supraorbital horns and a smaller pyramidal horn on the nose. It also had a bone collar with spikes along the edges.
Dinosaurs became extinct 65 million years ago, and mammals took over their habitat and dominant position on land. There is much in common between them, in particular, mammals use the same devices for attack and defense as dinosaurs. Lions and tigers, like Mesozoic theropods, are distinguished by their muscular build and sharp teeth and claws. And porcupines, hedgehogs and armadillos acquired shells and spines, that is, passive protection, like stegosaurs and ankylosaurs. Horns as a means of defense have not lost their relevance - they are used by rhinoceroses, buffalos and moose. Where does this similarity come from? We cannot say that mammals inherited all this from dinosaurs, since both groups of animals are not directly related. Biologists have another explanation: a largely similar habitat, as well as common features anatomical structure, similar sizes of individuals led to the fact that mammals developed the same behavioral strategies as dinosaurs.
Illustrations by Olga Orekhova-Sokolova
