Front tyrannosaurus. Other ancient reptiles. The female Tireks were larger than the males.
Tirex (Tyrannosaurus Rex) is by far the most popular dinosaur that lived on our planet. He became the hero of a huge number of books, films, TV shows and even video games.
For a very long time, Tirex was considered the most powerful carnivore that ever walked the Earth.
10 Little-Known Facts About Tirex
1 Tyrannosaurus Rex Was Not The Largest Carnivorous Dinosaur
Most people subconsciously believe that the North American Tyrannosaurus Rex, at 12 meters long from head to tail and weighing up to 9 tons, was the largest carnivorous dinosaur that ever walked the planet. However, an interesting fact is that in ancient times there were two types of dinosaurs that surpassed the Tirex in size - this is the South American Giganotosaurus, which weighed about nine tons and grew up to 14 meters long, and the North African Spinosaurus, which weighed more than 10 tons. Unfortunately, these theropods never had the opportunity to fight among themselves, because they lived in different times and in different lands, they were separated by thousands of miles and millions of years.
2. Tirex's front legs weren't as tiny as many people think.
One anatomical feature of the Tyrannosaurus Rex that many scoff at is its front legs, which appear disproportionately tiny compared to the rest of its massive body. But in reality, T. Rex's front legs were over 1 meter long and may have been capable of lifting up to 200 kg.
You will be interested to know that the most caricature-tiny front legs belong to the giant Carnotaurus. His arms were like tiny bumps.
3. Tirex had very bad breath.
Of course, most dinosaurs of the Mesozoic era did not have the ability to brush their teeth, and very few of them were denticulate. Some experts believe that the remains of rotten meat contaminated with bacteria that were constantly present between the terrible teeth made the bite of the Tirex poisonous. Such a bite would infect (and ultimately kill) the bitten victim. The problem is that this process would probably take days or weeks.
4 Female Tireks Were Bigger Than Males
We don't know for sure yet, but there is good reason to believe (based on the size of T. rex fossils found and the shape of their hips) that female T. rex outsized their males by 800 kg, a sign of sexual dimorphism.
What for? The most likely reason is that the females of the species had to lay huge eggs, which is why evolution gave females such large thighs, or perhaps females were simply more experienced hunters than males (as is the case with modern lions) and consumed more food.
5. The average lifespan of a Tirex was about 30 years.
It is difficult to infer the lifespan of dinosaurs from their fossilized remains, but based on the analysis of skeletal specimens found, paleontologists suggest that Tyrannosaurus Rex may have lived up to 30 years. Since this dinosaur was at the top of the food chain in its range, most likely its death was from old age, disease, or starvation, and not from fights with predators. Very rarely, a Tyrannosaurus rex could die from the teeth of another predator when it was too young and weak. (By the way, in parallel with T. Rex, Titanosaurs may have lived, whose weight exceeded 50 tons, their life expectancy was about 100 years!)
6. Tirex was hunting and picking up carrion
For years, paleontologists have debated whether T. Rex was a vicious killer, or a commonplace scavenger, that is, did he actively hunt, or pick up the carcasses of dinosaurs that died of old age or disease? Today, these contradictions seem rather strange, since the Tyrannosaurus Rex could use these two ways of subsistence simultaneously, like any massive predatory animal that constantly wanted to satisfy its hunger.
7 T. Rex Hatchlings May Have Feathered
We all know that dinosaurs are the progenitors of birds, and that some carnivorous dinosaurs (especially carnivores) were covered in feathers. Consequently, some paleontologists believe that all tyrannosaurs, including T. rex, must have been covered in feathers at some point in their life cycle, most likely when they first hatched from their eggs. This conclusion is supported by the discovery of feathered Asian tyrannosaurs such as Dilong and the nearly equal T. rex Yutyrannus.
8. Tyrannosaurus Rex, most of all loved to hunt triceratops
If you think that Mayweather vs. Pacquiao was the most brutal boxing fight, then you are greatly mistaken. Imagine a hungry eight-ton Tyrannosaurus Rex attacking a five-ton Triceratops! Such an unthinkable fight could certainly happen, since both of these dinosaurs lived in the late Cretaceous period in the lands of North America. Of course, the average T. Rex would prefer to deal with a sick or newly hatched Triceratops. But if he was too hungry, large individuals became his victims.
Back in 1996, a team of scientists from Stanford University, who studied the skull of this dinosaur, determined that T. Rex bit its prey with a force of 700 to 1400 kg. per square inch, the largest modern alligators bite with the same force. More detailed examination of the skulls showed that its bite force was in the range of 2,300 kilograms per square inch. (For comparison, an average adult can bite with about 80 kg per inch of force). The powerful jaws of the T. Rex could even bite through the horns of Ceratops himself!
10 Tyrannosaurus Rex Was Originally Named Manospondylus
When famed paleontologist Edward Pinker Cope unearthed the first fossilized T. Rex skeleton in 1892, he referred to it as "Manospondylus gigax - Greek" "giant slender vertebrae". After further impressive fossil searches, it was the then-president of the American Museum of Natural History, Henry Fairfield Osborn, who gave the immortal name Tyrannosaurus Rex, "king tyrant lizard."
In late 1905, newspapermen were writing excitedly about the bones of a prehistoric monster that paleontologists had unearthed in the badlands of Montana. The New York Times presented the "tyrant lizard" as the most formidable fighting animal in history. More than a hundred years have passed and Tyrannosaurus rex still excites the imagination of the public and paleontologists.
More than 12 meters from muzzle to tail, dozens of pointed teeth the size of a rail crutch: a Tyrannosaurus rex that lived 66 million years ago is not just one of the prehistoric predators, but an icon of ancient horror. He is so charismatic that the routine paleontological discussion can be inflated to ugly proportions.
This happened last year when a group of paleontologists presented their views on the fact that T. rex was not so much a hunter as a scavenger. The media presented it as a sensation, which infuriated paleontologists. In fact, the issue has long been resolved: enough evidence has been collected that suggests that the dinosaur not only ran after prey, but also did not disdain carrion.
It is only discussed what role living and dead animals played in his diet. What is especially annoying is that this not the most important problem hid other, more interesting aspects from the public.
For example, the origin of dinosaurs remains a mystery. Researchers cannot yet determine how the kings of the Cretaceous period (145-66 million years ago) grew from tiny dinosaurs of the Jurassic period (201-145 million years ago). What T. rex looked like as a young adult is heavily debated: it is suspected that some specimens described decades ago as separate species are in fact juveniles of other species.
Even the appearance of the Tyrannosaurus rex remains controversial: many argue that the giant body was covered with fluff and feathers, and not scales. The controversial question of why the animal had such a massive head and legs, but tiny forelimbs, has not gone anywhere.
Fortunately, there is enough material. “Fossils abound,” reports Stephen Brusatte of the University of Edinburgh (UK). “It is rare that so many good specimens remain from one species. With T. rex, we may wonder how it grew, what it ate, how it moved; many other dinosaurs we can't ask that."
In the first decades after Henry Fairfield Osborne named and described the rex rex, paleontologists saw it as the culmination of the growth of land carnivores. Therefore, T. rex was considered a descendant of the Allosaurus, a 9-meter predator that lived more than 80 million years earlier. Both of them, along with other carnivorous giants, were united in the taxon Carnosauria, with T. rex considered as the last and largest member of the ferocious family.
But in the 1990s, a more rigorous research method, cladistic analysis, began to be applied, and the evolutionary relationships between groups of dinosaurs were revised. It turned out that the ancestors of T. rex "a were small furry creatures that lived in the shadow of the allosaurus and other predators of the Jurassic period.
According to the new view, T. rex and its closest relatives (Tyrannosauridae) represent the top branch on a large evolutionary "bush" called Tyrannosauroidea, which arose about 165 million years ago. Among the earliest members of this group is Stokesosaurus clevelandi, a 2-3 m long bipedal predator that lived about 150 million years ago.
Little is known about this creature, but other early tyrannosauroids suggest that Stokesosaurus most likely had a long, low skull and slender forelimbs. In the Jurassic size hierarchy, early tyrannosauroids were at the very bottom. “By today's standards, they were at the level of lapdogs,” Mr. Brusatte jokes.
How did it happen that, over time, tyrannosaurs ended up at the top of the food chain in North America and Asia? So far, history is silent on this. A very small number of rocks aged 90-145 million years were found (it was during this period that tyrannosaurs crushed competitors), so the biodiversity of those times was reconstructed very fragmentarily. Nothing can be said about changes in sea level and climate in general, which could lead to the dominance of this particular group.
Recently, the main attention of paleontologists studying this time interval has been riveted to China. In 2009, Peter Makowitzky of the Field Museum in Chicago (USA) and his colleagues described a long-snouted Tyrannosaurus Rex called Xiongguanlong baimoensis, which was found in western China in rocks formed 100-125 million years ago.
In length, the animal reached almost four meters - a solid step forward compared to the tyrannosaurs of the Jurassic period. And in 2012, Xu Xing from the Institute of Vertebrate Paleontology and Paleoanthropology (PRC) and colleagues described a 9-meter tyrannosaurus named Yutyrannus huali, which belongs to the same era.
This may have been a crucial time interval when tyrannosaurs and allosaurs fought to the death for the same ecological niches. In the rocks from the north of China, Mr. Brusatte and his colleagues found the allosaurus Shaochilong maortuensis, 5-6 m long, which lived about 90 million years ago, that is, the sizes of competitors approximately coincided. But exactly when and why the tyrannosaurs won remains unknown.
It's just not interesting to portray our hero. He must be fighting someone! (Fig. ameeeeba.)
A similar situation with how T. rex looked in his youth. At the center of the discussion is Nanotyrannus lancensis, found in the same North American deposits as T. rex, and possibly growing in length over 6 m. At first it was considered a separate species, but some researchers see it as a minor T. rex "a.
According to Thomas Holtz, Jr. of the University of Maryland at College Park (USA), the differences between N. lancensis and T. rex resemble those between juveniles and adults of other tyrannosaur species. It should be noted that all samples of nanotyranus seem to him "minor".
Lawrence Whitmer of Ohio University (USA) does not think so. In 2010, he and his colleague Ryan Ridgeley, following a CT scan of a skull from the Cleveland Museum of Natural History (H. lancensis holotype), discovered unusual depressions in the skull and paranasal sinuses in the back of the skull, where air sacs were located during the dinosaur's life. With these formations, this specimen is very different from T. rex "a, which makes it possible to attribute the specimen to another species.
In addition to what was said, Peter Larson, president of the Black Hills Institute of Geological Research (USA), argues that the teeth of nanotyranus have too small serrations and are too densely packed. He also points out the differences in the anatomy of the glenoid cavity of the scapula and the openings in the skull.
However, critics have noted that some of this information was gleaned from the analysis of fossils that have not yet been described in the scientific literature. Moreover, scientists may even lose one of the key samples of nanotyranus, because in November it will be sold at auction in New York.
The hype has done its job: the specimen is estimated to fetch the owner $9 million. Most paleontologists simply refuse to consider fossils that are not freely available in a reputable museum. Does some private trader have the audacity to rob science?
“In the current situation, there is only one thing left - to advise again in a tired voice to look for other samples,” says Mr. Whitmer. For the nanotyrannus to be finally recognized as a separate species, either a young T. rex "a, more like an adult than a nanotyrannus, or the remains of an animal that was undoubtedly an adult nanotyrannus and clearly different from T. rex "and must be found. But Mr. Whitmer is pessimistic about the chances of stopping the discussion: "I don't know how much data is needed to convince everyone." T. rex is too charismatic, and views on it have already developed, so paleontologists will not simply abandon the usual opinion.
Another example of this is the controversy regarding the appearance of our hero. For generations, it has been depicted as being covered in scales like modern reptiles, although they are very distant relatives. But in the past two decades, specimens from many groups of dinosaurs with feathers and down have been discovered in China. Some of them are species closely related to T. rex.
In 2004, Mr. Xu described a small early Tyrannosaurus rex, Dilong paradoxus, with filament impressions around the tail, jaw, and other parts of the body. Is it a fluffy coat? The giant Y. huali was also feathered. The feathers of tyrannosaurus rexes were not like those of modern birds, but their primitive predecessors. According to Mr. Xu, they were primarily used for decoration, and later they were used for thermal insulation. It is possible that T. rex also proudly wore some kind of proto-feathers.
No, no one wants to say that T. rex looked like a chicken. We are talking about thin fibers, a kind of hairs - for example, on the muzzle.
Since not a single T. rex skin print has been found, all these are just assumptions, which is what skeptics use. Thomas Carr from Carthage College (USA) refers to skin prints of species close to T. rex that have not yet been described in the scientific literature. y, on which the scales are supposedly clearly visible. Well, it's entirely possible that early tyrannosauroids had feathers, but the subgroup of tyrannosaurids that includes T. rex evolved to abandon them in favor of scales.
The issue of feathers is very important not only for artists who no longer know how to depict the ancient miracle Yudo. If there were feathers, then we can assume some kind of mating games and talk about how the tyrannosaurus regulated body temperature.
Another secret is the giant's small hands. They are so short that you can't even reach your mouth with them. Paleontologists are all right with fantasy, and for a hundred years the most exotic hypotheses have been expressed: they say, it was so convenient to hug a partner during mating or climb steep slopes. Gradually, the opinion was established that the forelimbs are a rudiment. Countless cartoonists to this day depict tyrannosaurs, which on this basis are pursued by one embarrassment after another.
But Sarah Birch from Ohio University (USA) believes that such jokes are unfair. She studied the musculature of crocodiles and the only living descendants of dinosaurs, birds. If the arms of T. rex were indeed useless vestiges, they did not have any significant muscles, but the fossils retained signs that very significant muscles were attached to the bones.
So T. rex used his handles. But for what? Grabbed and held certain objects (for example, prey), as did all the other theropods?
Mr. Holz has a different idea. Estimates of muscle strength suggest that these short arms were still relatively weak tools. And since specimens were found with healed fractures of the forelimbs, the scientist concludes that they did not play a vital role. One thing remains: short arms could come in handy during mating games. Who knows, what if they were wrapped in multi-colored feathers? ..
(68-65 million years ago)
Its sense of smell was better developed than most other dinosaurs, and its eyesight was so sharp that even a hawk could not be compared with it. Plus, it was binocular, he could look in different directions, and the picture was reunited into one whole, which made it possible to determine the distance to the victim with sufficient accuracy, which the larger giganotosaurus did not have.
Tyrannosaurus rex is perhaps the most famous of all the carnivorous predators of the Cretaceous. He was one of the largest land predators, his mouth with a powerful jaw and strong teeth was considered the main weapon.
What did they eat and what kind of life did they lead?
There were several opinions about how and what this huge lizard ate, only carrion or still attacked other dinosaurs and reptiles. Most scientists agreed that he hunted smaller representatives of the animal world, although he did not disdain to profit from carrion. This was decided only after tyrannosaurus rex bite marks were found on the skeletons of other dinosaurs. They were so bloodthirsty that they did not hesitate to attack their own kind. It was later revealed that it was not uncommon for tyrannosaurs to fight for territory with other large carnivores. Also, eye sockets testify to its predation.Details about the structure of the body
The skin was scaly, like a lizard's. The posture was slightly tilted, but even so, this bloodthirsty giant could easily look into the window of today's three-story house.
Dimensions
It could reach 13m in length, on average -12mHeight 5-5.5m
Body weight: was quite large - from 6 to 7 tons
Head
The largest skull in length reached 1m 53cm. The shape of the skull: wide at the back, and tapering in front, when viewed from above, it resembles the letter U together with the jaws. The brain is small in size, in terms of intelligence it could be compared with a crocodile.
The teeth were very sharp and long (15-30 cm long, the longest of any existing saur). The bite was very powerful, the pressure of several tons exceeded the force of a lion's bite by 15 times. With the help of jaws, he could crush any bones and even skulls, his enemies almost never survived after a bite.
limbs
There were four limbs, but he moved only on 2 hind limbs, the two front ones were small and completely undeveloped, unlike spinosaurus. The usual speed of movement is up to 20 km / h, if necessary, the tyrannosaurus could reach speeds of up to 60 km / h. The tail helped to maintain balance, it could also be a murder weapon - with its help it was easy to break the spine or cervical vertebrae. The hind legs were also very powerful, they had 4 fingers. 3 of them were supporting, and the last one did not even touch the ground.Video about tyrannosaurs №1.
Video #2.
Fight with King - Kong (from the movie King - Kong).
Tyrannosaur fight.
Tyrannosaurus (lat. Tyrannosaurus - "tyrant lizard") is a monotypic genus of predatory dinosaurs.
A group of coelurosaurs of the theropod suborder with the only valid species Tyrannosaurus rex (lat. rex - "king").Habitat: about 67-65.5 million years ago in the last century of the Cretaceous period - Maastrichtian.
Habitat: the western part of North America, which was then the island of Laramidia.
The last of the lizard dinosaurs that lived before the cataclysm that ended the age of the dinosaurs.
Appearance
A bipedal predator with a massive skull balanced by a long, stiff and heavy tail. The front paws were very small, but very strong, had two fingers with large claws.
The largest species of its family, one of the largest representatives of theropods and the largest land predators in the history of the Earth.
Dimensions
The largest known complete skeleton, FMNH PR2081 "Sue", reaches a length of 12.3 meters, a height of 4 meters to the hip. The mass of this individual during life could reach 9.5 tons.
But fragments were found that belonged to even larger tyrannosaurs. Gregory S. Paul estimates that Specimen UCMP 118742 (81 cm long maxillary bone) is approximately 13.6 meters long, 4.4 meters high at the hips, and weighs 12 tons.
Lifestyle
Tyrannosaurus rex was the largest carnivore in its ecosystem and most likely was an apex predator, preying on hadrosaurs, ceratopsians, and possibly sauropods. However, some researchers suggest that it fed mainly on carrion. Most scientists believe that the tyrannosaurus could both hunt and eat carrion (it was an opportunistic predator).
Body type
The neck of Tyrannosaurus, like other theropods, was S-shaped, short and muscular, holding a massive head. The forelimbs had only two fingers with claws and a small metacarpal bone - a vestige of the third finger. The hind limbs were the longest relative to the body among all theropods.
The spine is composed of 10 cervical, 12 thoracic, five sacral and about 40 tail vertebrae. The tail was heavy and long, acting as a balancer to balance the massive head and overweight torso. Many bones of the skeleton were hollow, which greatly reduced their weight with almost the same strength.
Scull
The largest complete tyrannosaurus skull ever found reaches a length of about one and a half meters. The skull of Tyrannosaurus rex differed from that of large non-tyrannosaurid theropods. Its back was wide and its snout narrow, thanks to which the lizard had highly developed binocular vision, which allows the brain to form a reliable model of space, estimating distances and sizes. Presumably, this testifies in favor of a predatory lifestyle.
The nasal and some other bones of the skull were united, preventing foreign objects from getting between them. The bones of the skull were airy, it had paranasal sinuses, like other non-avian dinosaurs, which made them lighter and more flexible. These properties signify in tyrannosaurids a tendency towards an increase in bite force, which significantly exceeded the bite force of all non-tyrannosaurid theropods in these lizards.
The end of the upper jaw was U-shaped, while in most non-tyrannosaurids it was V-shaped. This form made it possible to increase the volume of tissues that the tyrannosaurus tore out of the victim's body in one bite, and also increased the pressure of the lizard's front teeth.
Tyrannosaurus rex has a well-defined heterodontism, the difference in teeth in shape and function.
The teeth on the anterior side of the maxilla are D-shaped in cross-section, closely spaced, equipped with a chisel-shaped blade, reinforcing ridges, and an inward curvature. Due to this, the risk of breaking a tooth during biting and dragging the victim was reduced.
Other teeth are stronger and more massive, more like bananas than daggers, set wider apart and having reinforcing ridges.
The largest of the found teeth reached a height of 30 centimeters together with the root, being the largest carnivorous dinosaur teeth ever found.
Tyrannosaurids did not have lips, their teeth remained open, like modern crocodiles. On the muzzle were large scales with pressure receptors.
bite force
Research by paleontologists Carl Bates and Peter Falkingham in 2012 suggested that the bite force of a Tyrannosaurus rex was the greatest among all land animals that have ever lived on Earth. According to the teeth marks on the bones of Triceratops, the back teeth of an adult Tyrannosaurus rex could compress with a force of 35 to 37 kilonewtons, which is 15 times the largest measured bite force of an African lion, three and a half times the bite force of an Australian combed crocodile, and seven times more Allosaurus bite force.
Lifespan
The smallest specimen found, LACM 28471 ("Jordanian theropod") weighed 30 kilograms, while the largest, FMNH PR2081 "Sue", weighed over 5400 kilograms. Histology of Tyrannosaurus bones showed that at the time of death, "Jordanian theropod" was two years old, and "Sue" was 28 years old. Thus, the maximum lifespan of tyrannosaurs probably reached 30 years.
Paleontologists believe tyrannosaurs "lived fast and died young" because they reproduced quickly and lived too dangerous lives.
Posture
The initial reconstructions of scientists depicting the Tyrannosaurus rex, like other bipedal lizards, in the pose of a "three-legged tripod" turned out to be incorrect. The lizards of this type of posture moved, keeping the body, tail and head almost on the same line, horizontal with respect to the ground. The tail was straight and constantly curved to the sides in opposition to the movements of the head.
Forelimbs
The forelimbs of a Tyrannosaurus rex are extremely small in relation to the size of the body, reaching only one meter in length. However, their bones have large areas for muscle attachment, indicating great strength.
Scientists believe that they could serve to get up from a resting position, to hold a sexual partner during mating, and also to hold a victim trying to escape.
The exceptionally thick, non-porous surface layer of the bones of these limbs indicates the ability to withstand significant load. The biceps brachii of an adult Tyrannosaurus rex was capable of lifting a load of 200 kilograms. The shoulder muscle worked in parallel with the biceps, increasing elbow flexion. The T-rex's biceps were three and a half times more powerful than a human's. The massive bones of the forelegs, muscular strength and limited range of motion speak of a special forelimb system of the tyrannosaurus rex, which developed to firmly hold the victim, making a desperate effort to escape.
Leather and feathers
Scientists believe that at least parts of the body of T. rex had feathers. This version is based on the presence of feathers in smaller related species.
Tyrannosauroid feathers were first discovered in the small dinosaur Dilong paradoxus from China's famous Yixian Formation. Its fossilized skeleton, like that of many other theropods from the same formation, was fringed with a layer of filamentous structures commonly thought of as proto-feathers. Larger tyrannosauroids were found to have fossilized scales, so the scientists concluded that the number of feathers decreased with age, because. immature individuals were feathered to keep warm, and by adulthood, large animals had only scales. However, subsequent discoveries showed that even some large tyrannosauroids had feathers over most of their bodies.
It is possible that the number of feathers and the nature of the cover could change in tyrannosauroids depending on the season, changes in the size of the lizards, climate changes, or other factors.
thermoregulation
Most likely, the tyrannosaurus was warm-blooded, as it led a very active lifestyle. This is supported by the high growth rate of tyrannosaurs, similar to that of mammals and birds. Growth charts show that their growth stopped at immature age, unlike most other vertebrates.
Scientists analyzing the ratio of oxygen isotopes in the bones of tyrannosaurus found that the temperature of the spine and tibia differed by no more than 4-5 ° C, which indicates the ability of the tyrannosaurus to maintain a constant internal body temperature due to a metabolism that is average between the metabolisms of cold-blooded reptiles and warm-blooded mammals.
Even if a Tyrannosaurus rex maintained a constant body temperature, this does not mean that it was completely warm-blooded, since such thermoregulation could be explained by an advanced form of mesothermy observed in the leatherback sea turtles that exist today.
Motion
Most of the mass of Tyrannosaurus rex is removed from its center of gravity, it could reduce this distance by arching its back and tail and pressing its head and limbs to the body. Most likely, the tyrannosaurus turned rather slowly, it could make a 45 ° turn in 1-2 seconds.
Tyrannosaurus Max Speed:
According to average estimates, about 39.6 km / h or 11 m / s.
The lowest rating is from 18 km/h or 5 m/s.
72 km/h or 20 m/s.
Numerous footprints of large theropods have been found while walking, but none have been found while running. This may mean that tyrannosaurs were not capable of running. However, other experts noted the greater development of the muscles of the legs of the tyrannosaurus compared to any modern animal, which gives them reason to believe that it could reach speeds of 40-70 kilometers per hour.
For such a massive animal, a fall while running fast could have resulted in fatal injuries. However, modern giraffes can reach speeds of up to 50 km / h, risking breaking a leg or being crushed to death, not only in the wild, but also in a zoo. It is likely that in case of need, the tyrannosaurus also exposed itself to such a risk.
In a 2007 study, a running speed computer model estimated a Tyrannosaurus rex's top speed at 29 km/h (8 m/s). By comparison, a sprinter can reach a top speed of 43 km/h (12 m/s). The maximum speed of a three-kilogram (possibly juvenile) Compsognathus specimen was estimated by the model at 64 km/h (17.8 m/s).
Brain and sense organs
Coelurosaurids had enhanced sensory abilities. This is evidenced by fast and well-coordinated movements of the pupils and head, the ability to pick up low-frequency sounds, thanks to which the tyrannosaurus detected prey at great distances, as well as an excellent sense of smell.
It is also believed that Tyrannosaurus rex had very sharp eyesight. Its binocular range was 55 degrees - more than that of a modern hawk. The visual acuity of a Tyrannosaurus rex exceeded that of a human by 13 times, respectively, exceeding the visual acuity of an eagle, which is only 3.6 times higher than a human. All this allowed the tyrannosaurus to distinguish objects at a distance of 6 kilometers, while a person can only recognize them at a distance of 1.6 kilometers.
Tyrannosaurus rex's heightened depth perception may have been related to its prey items. They were the armored dinosaur Ankylosaurus, the horned dinosaur Triceratops, and the duck-billed dinosaurs, which either ran away or camouflaged themselves and hid.
Tyrannosaurus rex had large olfactory bulbs and olfactory nerves relative to the size of its entire brain, allowing it to smell carrion from a great distance. It is likely that Tyrannosaurus rex's sense of smell is comparable to that of modern vultures.
Tyrannosaurus rex's very long cochlea is uncharacteristic of a theropod. Cochlear length has been linked to hearing acuity, showing how important hearing was to his behavior. Studies have shown that Tyrannosaurus is best at picking up low-frequency sounds.
The eye sockets of the Tyrannosaurus rex were located so that the gaze was directed forward, the lizard had good binocular vision - better than that of hawks. Horner noted that in the tyrannosaur lineage there is a steady improvement in binocular vision, while scavengers do not need increased depth perception.
In the modern world, excellent stereoscopic vision is characteristic of fast-running predators.
Tyrannosaurus tooth marks are quite common on Triceratops bones with no signs of healing. Fossils exist showing smaller tyrannosaurids, possibly young tyrannosaurids, successfully hunting large Triceratops.
While examining the "Sue" specimen, Peter Larson found a fibula and tail vertebrae fused after a fracture, as well as cracks in the facial bones and a tooth stuck in the cervical vertebrae of another tyrannosaurus rex. This may indicate aggressive behavior between tyrannosaurs. It is not known for sure whether tyrannosaurs were active cannibals or simply engaged in intraspecific competition for territory or mating rights.
Further research showed that lesions on the facial bones, fibula and vertebrae were due to an infectious disease.
The current view is that tyrannosaurs occupied different ecological niches depending on size and age, similar to modern crocodiles and monitor lizards.
So, newborn cubs most likely fed on small prey, and as they grew, they switched to larger ones. Perhaps the largest tyrannosaurs hunted carrion, taking prey from smaller relatives.
poisonous saliva
There is a hypothesis that the tyrannosaurus could kill the victim with the help of its infected saliva. Between the teeth of a tyrannosaurus rex, rotten remnants of meat could accumulate, a bite of a tyrannosaurus rex infected the victim with harmful bacteria.
Probably, the tyrannosaurus pulled out pieces of meat from the carcass, shaking its head from side to side, as crocodiles do. In one bite, an adult tyrannosaurus rex could tear out a piece of meat weighing 70 kg from the body of the victim.
paleoecology
Tyrannosaurus rex ranged from Canada to Texas and New Mexico. Triceratops dominated among the herbivores in the northern regions of this range, while sauropods of the Alamosaurus species dominated in the southern regions. Tyrannosaurus rex remains have been found in a variety of ecosystems, from inland landmasses to wetlands and arid and semi-arid (arid and semi-arid) plains.
Several notable Tyrannosaurus rex finds have been made in the Hell Creek Formation. During the Maastrichtian era, the area was subtropical, with a warm and humid climate. Flora is represented mainly by flowering plants, there were coniferous trees like metasequoia and araucaria. Tyrannosaurus shared a habitat with Triceratops and its closely related Torosaurus, as well as the platypus edmontosaurus, armored ankylosaurus, pachycephalosaurus, thescelosaurus, and the theropods ornithomimus and troodon.
Another deposit of Tyrannosaurus remains is the Lance Formation of Wyoming. Millions of years ago, it was a bayous ecosystem, similar to the modern Gulf Coast. The fauna of this formation is very similar to the fauna of Hell Creek, however, the niche of the ornithomim was occupied by the strutiomym. Also there lived a small representative of ceratopsians - leptoceratops.
In the southern regions of the range, the tyrannosaurus lived with the alamosaurus, torosaurus, edmontosaurus, with the representative of the ankylosaurs Glyptodontopelta and the giant pterosaur quetzalcoatl. Semi-arid plains prevailed there, on the site of which the Western Inland Sea previously ran.
Tyrannosaurus - this monster is called the brightest representative of the tyrannosauroid family. It disappeared from the face of our planet faster than most other dinosaurs, having lived for several million years at the end of the Cretaceous period.
Description of tyrannosaurus rex
The generic name Tyrannosaurus comes from the Greek roots τύραννος (tyrant) + σαῦρος (lizard). The Tyrannosaurus rex, which lived in the USA and Canada, belongs to the lizard-like order and represents the only species of Tyrannosaurus rex (from rex "king, king").
Appearance
Tyrannosaurus Rex is considered perhaps the largest predator during the existence of the Earth - it was almost twice as long and heavier.
Body and limbs
The complete skeleton of a Tyrannosaurus rex contains 299 bones, 58 of which are in the skull. Most of the bones of the skeleton were hollow, which had little effect on their strength, but reduced weight, compensating for the prohibitive bulkiness of the beast. The neck, like that of other theropods, was S-shaped, but was short and thick to support the massive head. The spine included:
- 10 cervical;
- a dozen breasts;
- five sacral;
- 4 dozen tail vertebrae.
Interesting! Tyrannosaurus rex had an elongated massive tail, which acted as a balancer, which had to balance the overweight body and heavy head.
The forelimbs, armed with a pair of clawed fingers, seemed underdeveloped and inferior in size to the hind limbs, which were unusually powerful and long. The hind limbs ended in three strong fingers, where strong curved claws grew.
Skull and teeth
One and a half meters, or rather 1.53 m - this is the length of the largest known complete skull of a tyrannosaurus rex that fell into the hands of paleontologists. The bone skeleton surprises not so much with its size as with its shape (different from other theropods) - it is widened at the back, but noticeably narrowed at the front. This means that the lizard's gaze was not directed to the side, but forward, which indicates its good binocular vision.
Another feature speaks of a developed sense of smell - large olfactory lobes of the nose, somewhat reminiscent of the structure of the nose in modern feathered scavengers, for example,.
The grip of a Tyrannosaurus rex, due to the U-shaped bend of the upper jaw, was more palpable than the bites of carnivorous dinosaurs (with a V-shaped bend), not included in the family of tyrannosaurids. The U-shape increased the pressure of the front teeth and made it possible to tear solid pieces of meat with bones from the carcass.
The teeth of the lizard had a different configuration and different functions, which in zoology is commonly called heterodontism. The teeth growing in the upper jaw were superior in height to the lower teeth, with the exception of those located in the back.
Fact! To date, the most gigantic tooth of a Tyrannosaurus rex is considered to be one found, whose length from root (inclusive) to tip is 12 inches (30.5 cm).
Teeth of the anterior side of the upper jaw:
- resembled daggers;
- closely intertwined;
- bent inward;
- had reinforcing ridges.
Thanks to these features, the teeth held tightly and rarely broke when the tyrannosaurus tore apart its prey. The rest of the banana-shaped teeth were even stronger and more massive. They were also equipped with reinforcing ridges, but differed from the chisel-shaped ones in a wider arrangement.
Lips
The hypothesis about the lips that carnivorous dinosaurs had was voiced by Robert Reisch. He suggested that the teeth of predators covered the lips, moisturizing and protecting the first from destruction. According to Reish, the Tyrannosaurus rex lived on land and could not do without lips, unlike crocodiles that live in water.
Reisch's theory was challenged by his US colleagues led by Thomas Carr, who published a description of Daspletosaurus horneri (a new tyrannosaurid species). The researchers emphasized that the lips do not fit at all with his muzzle, covered with flat scales up to the dentition.
Important! Daspletosaurus did without lips, in place of which there were large scales with sensitive receptors, like in the current crocodiles. The teeth of Daspletosaurus did not need lips, just like the teeth of other theropods, including Tyrannosaurus Rex.
Paleogeneticists are sure that the presence of lips would harm the tyrannosaurus rex more than the daspletosaurus - it would be an additional vulnerable zone in fights with rivals.
Plumage
The soft tissues of the Tyrannosaurus rex, poorly represented by the remains, have been studied (in comparison with its skeletons) clearly insufficiently. For this reason, scientists still doubt whether he had plumage, and if so, how dense and in what parts of the body.
Some paleogeneticists came to the conclusion that the tyrant lizard was covered with thread-like, akin to hair, feathers. This hairline was most likely in young/young animals, but fell out as they matured. Other scientists believe that the plumage of Tyrannosaurus rex was partial, with feathered areas interspersed with scaly ones. According to one version, feathers could be observed on the back.
Tyrannosaurus rex dimensions
Tyrannosaurus rex is recognized as one of the largest theropods, as well as the largest species in the tyrannosaurid family. Already the first fossils found (1905) suggested that Tyrannosaurus grew up to 8–11 m, surpassing Megalosaurus and Allosaurus, whose length did not exceed 9 meters. True, among the tyrannosauroids were dinosaurs and larger than Tyrannosaurus rex - such as Giganotosaurus and Spinosaurus.
Fact! In 1990, the skeleton of a Tyrannosaurus Rex was brought to light, after reconstruction it received the name Sue, with very impressive parameters: 4 m height to the hip with a total length of 12.3 m and a mass of about 9.5 tons. True, a little later, paleontologists found fragments of bones, which (judging by their size) could also belong to larger than Sue, tyrannosaurs.
So, in 2006, the University of Montana announced the possession of the most voluminous skull of a tyrannosaurus, found back in the 1960s. After the restoration of the destroyed skull, scientists stated that it is longer than Sue's skull by more than a decimeter (1.53 versus 1.41 m), and the maximum opening of the jaws is 1.5 m.
A couple more fossils have been described (a foot bone and anterior part of the upper jaw), which, according to calculations, could belong to two tyrannosaurs 14.5 and 15.3 m long, each of which weighed at least 14 tons. Further research by Phil Curry showed that the calculation of the length of the lizard cannot be done based on the size of scattered bones, since each individual has individual proportions.
Lifestyle, behavior
Tyrannosaurus walked with its body parallel to the ground, but with its tail slightly raised to balance its heavy head. Despite the developed leg muscles, the tyrant lizard could not run faster than 29 km / h. This speed was obtained from a computer simulation of the running of a Tyrannosaurus rex, conducted in 2007.
A more frisky run threatened the predator with falls, associated with tangible injuries, and sometimes even death. Even when pursuing prey, the tyrannosaurus kept reasonable caution, maneuvering between bumps and pits so as not to crash down from the height of its gigantic growth. Once on the ground, the Tyrannosaurus (not seriously injured) tried to rise, leaning on its front paws. At least, this is the role that Paul Newman assigned to the forelimbs of the lizard.
This is interesting! Tyrannosaurus was an extremely sensitive animal: in this he was helped by a sharper sense of smell than that of a dog (he felt the smell of blood for several kilometers).
The pads on the paws also helped to be always on the alert, taking the vibrations of the earth and broadcasting them up, along the skeleton to the inner ear. Tyrannosaurus had an individual territory, marking the boundaries, and did not go beyond it.
Tyrannosaurus rex, like many dinosaurs, was considered a cold-blooded animal for quite a long time, and they moved away from this hypothesis only in the late 1960s thanks to John Ostrom and Robert Bakker. Paleontologists have stated that Tyrannosaurus rex was active and warm-blooded.
This theory is confirmed, in particular, by its rapid growth rate, comparable to the growth dynamics of mammals/birds. The growth curve of tyrannosaurs has an S-shape, where a rapid increase in mass was noted at about 14 years of age (this age corresponds to a weight of 1.8 tons). In the accelerated phase of growth, the lizard added 600 kg annually for 4 years, slowing down weight gain upon reaching 18 years.
Some paleontologists still doubt that Tyrannosaurus was fully warm-blooded, not denying its ability to maintain a constant body temperature. Scientists explain this thermoregulation of one of the forms of mesothermia that leatherback turtles exhibit.
Lifespan
From the point of view of paleontologist Gregory S. Paul, tyrannosaurs multiplied rapidly and died too early due to the fact that their life was full of dangers. Estimating the lifespan of tyrannosaurs and at the same time the rate of their growth, the researchers studied the remains of several individuals. The smallest specimen, named Jordanian theropod(with an estimated weight of 30 kg). An analysis of its bones showed that at the time of death, the tyrannosaurus was no more than 2 years old.
Fact! The biggest find, nicknamed Sue, looked like a real giant against his background, whose weight was approaching 9.5 tons, and his age was 28 years. This period was considered the maximum possible for the species Tyrannosaurus rex.
sexual dimorphism
Dealing with the difference between the sexes, paleogenetics paid attention to body types (morphs), highlighting two that are common to all types of theropods.
Body Types of Tyrannosaurus Rex:
- robust - massiveness, developed muscles, strong bones;
- gracile - thin bones, slenderness, less pronounced muscles.
Separate morphological differences between the types formed the basis for the division of tyrannosaurs according to sexual characteristics. Females were classified as robust, taking into account that the pelvis of robust animals was expanded, that is, they most likely laid eggs. It was believed that one of the main morphological features of robust pangolins is the loss/reduction of the chevron of the first tail vertebra (this was associated with the release of eggs from the reproductive canal).
In recent years, conclusions about the sexual dimorphism of Tyrannosaurus rex, which were based on the structure of the chevrons of the vertebrae, have been recognized as erroneous. Biologists took into account that the difference between the sexes, in particular, in crocodiles, does not affect the reduction of the chevron (2005 studies). In addition, a full-fledged chevron also showed off on the first tail vertebra, which belonged to a remarkably strong individual nicknamed Sue, which means that this feature is characteristic of both body types.
Important! Paleontologists decided that the differences in anatomy were caused by the habitat of a particular individual, since the remains were found from Saskatchewan to New Mexico, or age-related changes (old tyrannosaurs were presumably robust).
Having reached a dead end on the identification of male / female species of Tyrannosaurus rex, scientists with a high degree of probability found out the sex of a single skeleton named Bi-rex. In these remains, soft fragments were found that were identified as analogues of medullary tissue (supplying calcium for shell formation) in modern birds.
Medullary tissue is usually present in the bones of females, but in rare cases it is also formed in males when they are injected with estrogens (female reproductive hormones). That is why Bi-rex was unequivocally recognized as a female who died during ovulation.
Discovery history
The first Tyrannosaurus rex fossils were found by an expedition of the Museum of Natural History (USA), led by Barnum Brown. This happened in 1900 in Wyoming, and a couple of years later a new partial skeleton was discovered in Montana, which took 3 years to process. In 1905, the finds received different specific names. The first is Dynamosaurus imperiosus and the second is Tyrannosaurus rex. True, the following year, the remains from Wyoming were also assigned to the species Tyrannosaurus rex.
Fact! In the winter of 1906, The New York Times informed readers of the discovery of the first Tyrannosaurus rex, whose partial skeleton (including the giant bones of the hind legs and pelvis) settled in the hall of the American Museum of Natural History. Between the limbs of the lizard, to enhance the impression, they placed the skeleton of a large bird.
The first complete skull of a tyrannosaurus rex was removed only in 1908, and its complete skeleton was mounted in 1915, all in the same Museum of Natural History. Paleontologists made a mistake by supplying the monster with the three-toed forepaws of an allosaurus, but corrected it after the appearance of an individual Wankel Rex. This specimen, consisting of a 1/2 skeleton (with a skull and complete forelegs) was excavated from the Hell Creek deposits in 1990. A specimen nicknamed Wankel Rex died at about 18 years old, and in its lifetime weighed about 6.3 tons with a length of 11.6 m. These were one of the few dinosaur remains where blood molecules were found.
This summer, and also in the Hell Creek Formation (South Dakota), not only the largest, but also the most complete (by 73%) Tyrannosaurus rex skeleton was found, named after paleontologist Sue Hendrickson. In 1997 the skeleton Sue, whose length was 12.3 m with a skull of 1.4 m, was sold for $7.6 million at auction. The skeleton was purchased by the Field Museum of Natural History, which opened it to the public in 2000 after cleaning and restoration, which took 2 years.
Scull MOR 008, found by W. McManis much earlier than Sue, namely in 1967, but finally restored only in 2006, is famous for its size (1.53 m). Sample MOR 008 (fragments of the skull and scattered bones of an adult tyrannosaurus rex) is on display at the Museum of the Rockies (Montana).
In 1980, they found the so-called black handsome ( black beauty), whose remains were blackened by exposure to minerals. The fossils of the pangolin were discovered by Jeff Baker, who saw a huge bone on the river bank while fishing. A year later, the excavations were completed, and Black Beauty moved to the Royal Tyrrell Museum (Canada).
Another tyrannosaurus, named Stan in honor of paleontology lover Stan Sacrison, found in South Dakota in the spring of 1987, but they did not touch it, mistaking it for the remains of a Triceratops. The skeleton was removed only in 1992, having found many pathologies in it:
- broken ribs;
- fused cervical vertebrae (after a fracture);
- holes in the back of the skull from the teeth of a tyrannosaurus rex.
Z-REX are fossil bones found in 1987 by Michael Zimmershid in South Dakota. In the same area, however, already in 1992, an excellently preserved skull was discovered, which was excavated by Alan and Robert Dietrich.
Remains under the name Bucky, taken in 1998 from the Hell Creek area, are notable for the presence of fused forked clavicles, since the fork is called the link between birds and dinosaurs. T. rex fossils (along with remains of Edmontosaurus and Triceratops) have come to light in the lowlands of Bucky Derflinger's cowboy ranch.
One of the most complete Tyrannosaurus skulls ever recovered to the surface, the skull (94% integrity) belonging to the specimen is recognized Rees Rex. This skeleton was found in a deep gully in a grassy slope, also in the Hell Creek Geological Formation (northeast Montana).
Range, habitats
The fossils were found in deposits of the Maastrichtian, revealing that a Tyrannosaurus rex lived during the Late Cretaceous period from Canada to the United States (including the states of Texas and New Mexico). Curious specimens of the tyrant lizard were found in the northwestern United States in the Hell Creek Formation - during the Maastrichtian, there were subtropics here, with their excess heat and humidity, where coniferous trees (araucaria and metasequoia) were interspersed with flowering plants.
Important! Judging by the location of the remains, the tyrannosaurus rex lived in various biotopes - arid and semi-arid plains, swampy areas, as well as on land remote from the sea.
Tyrannosaurus rex coexisted with herbivorous and carnivorous dinosaurs such as:
- platypus edmontosaurus;
- torosaurus;
- ankylosaurus;
- thescelosaurus;
- pachycephalosaurus;
- ornithomimus and troodon.
Another famous deposit of Tyrannosaurus rex skeletons is a geological formation in Wyoming, which millions of years ago resembled an ecosystem like the modern Gulf of Mexico coast. The fauna of the formation practically repeated the fauna of Hell Creek, except that instead of ornithomimus, struthiomimus lived here, and even leptoceratops (a small representative of ceratopsians) was added.
In the southern sectors of its range, Tyrannosaurus rex shared territory with Quetzalcoatl (a huge pterosaur), Alamosaurus, Edmontosaurus, Torosaurus, and one of the ankylosaurs called Glyptodontopelta. In the south of the range, semi-arid plains dominated, which appeared here after the disappearance of the Western Inland Sea.
Tyrannosaurus Rex Diet
Tyrannosaurus rex was larger than most carnivorous dinosaurs in its native ecosystem, and therefore recognized as an apex predator. Each tyrannosaurus preferred to live and hunt alone, strictly in its own area, which was more than one hundred square kilometers.
From time to time, tyrant lizards wandered into the adjacent territory and began to assert their rights to it in violent skirmishes, often leading to the death of one of the combatants. With this outcome, the winner did not disdain the meat of a relative, but more often pursued other dinosaurs - ceratopsians (torosaurs and triceratops), hadrosaurs (including anatotitans) and even sauropods.
Attention! A protracted discussion about whether the Tyrannosaurus rex is a true apex predator or a scavenger led to the final conclusion - Tyrannosaurus rex was an opportunistic predator (hunted and ate carrion).
Predator
The following arguments support this thesis:
- the eye sockets are located so that the eyes are not directed to the side, but forward. Such binocular vision (with rare exceptions) is observed in predators who are forced to accurately estimate the distance to the prey;
- tyrannosaurus tooth marks left on other dinosaurs and even representatives of their own species (for example, a healed bite on the nape of a Triceratops is known);
- large herbivorous dinosaurs that lived at the same time as tyrannosaurs had protective shields / plates on their backs. This indirectly indicates the threat of attack from giant predators such as Tyrannosaurus rex.
Paleontologists are sure that the lizard attacked the intended object from an ambush, overtaking it with one powerful jerk. Due to its considerable mass and low speed, it was unlikely that he was capable of a protracted pursuit.
The tyrannosaurus chose mostly weakened animals as victims - sick, elderly or very young. Most likely, he was afraid of adults, since individual herbivorous dinosaurs (ankylosaurus or triceratops) could stand up for themselves. Scientists admit that the tyrannosaurus, using its size and power, took prey from smaller predators.
scavenger
This version is based on other facts:
- the sharpened sense of smell of a tyrannosaurus rex, provided with many olfactory receptors, like in carrion birds;
- strong and long (20-30 cm) teeth, designed not so much to kill prey, but to crush bones and extract their contents, including bone marrow;
- the low speed of movement of the lizard: he did not run as much as he walked, which made the pursuit of more maneuverable animals meaningless. It was easier to find carrion.
Defending the hypothesis about the predominance of carrion in the diet of the lizard, paleontologists from China examined the humerus of a saurolophus, which was gnawed by a representative of the tyrannosaurid family. After examining the damage to the bone tissue, scientists considered that they were inflicted when the carcass began to decompose.
bite force
It was thanks to her that the tyrannosaurus easily crushed the bones of large animals and tore apart their carcasses, getting to mineral salts, as well as bone marrow, which remained inaccessible to small carnivorous dinosaurs.
Interesting! The bite force of Tyrannosaurus rex far surpassed both extinct and living predators. This conclusion was made after a series of special experiments in 2012 by Peter Falkingham and Carl Bates.
Paleontologists examined the teeth marks on the bones of Triceratops and made a calculation showing that the back teeth of an adult tyrannosaurus rex closed with a force of 35-37 kilonewtons. This is 15 times greater than the maximum bite force of an African lion, 7 times greater than the possible bite force of an Allosaurus and 3.5 times greater than the bite force of the crowned record holder, the Australian combed crocodile.