In the "Reptiles and Amphibians" section, for the first time we decided to talk about such an animal, which was undoubtedly the king of beasts, if you can call it that. To begin with, we will find out what the tyrannosaurus means in Latin, we will name the closest relatives of this predator. Then we'll talk more about its appearance and size. Of course, an article about the tyrannosaurus would not be complete if we did not tell who he hunted, where and when he lived on Earth.
Tyrannosaurus Rex is one of the most famous carnivorous dinosaurs. Even a modern lion can not be compared with him. It owes part of its popularity to the media, especially the release of the movie Jurassic Park. At the American Museum of Natural History in New York, this is the most beloved exhibit by visitors.
The meaning of the name Tyrannosaurus and its closest relatives
Tyrannosaurus - literally translated from Latin "tyrant lizard". This name comes from the ancient Greek words - "tyrant" and - "lizard, lizard." Rex means "king". So named and first described this dinosaur in 1905 by the famous American biologist and paleontologist Henry Fairfield Osborne, who at that time was president of the American Museum of Natural History in New York.
The genus Tyrannosaurus belongs to the Tyrannosaurus family and consists of only one animal species - Tyrannosaurus Rex - a large carnivorous dinosaur. In addition to it, Tyrannosaurids include another subfamily, which includes Albertosaurus, Alectrosaurus, Alioramus, Chingkankousaurus, Daspletosaurus, Eotiranus, Gorgosaurus, Nanotyrannus and Tarbosaurus.
Dimensions, appearance and structural features of Tirex
The largest and most complete Tirex skeleton ever found was named Sue, after its discoverer, paleontologist Sue Hendrickson. By carefully measuring Sue's bones, the scientists concluded that Tirex was one of the largest carnivorous dinosaurs. It was up to 4 meters (13 ft) high and 12.3 m (40 ft) long. Sue's recent analysis, which was published in 2011 in the journal PLoS ONE, shows that the Tyrannosaurus weighed as much as 9 tons (8160 kg to be exact).
The Tirex had powerful hips and a long, strong tail., which served not only as a deadly weapon, but primarily as a counterweight to its large head (Sue's skull is 1.5 m, or 5 feet long) and allowed the dinosaur to move quickly. In 2011, studies were conducted that were able to model the distribution of muscle tissue over the skeleton of a lizard. The results suggest that this carnivorous dinosaur could reach speeds of 17 to 40 km/h (10 to 25 mph).
The two-toed forepaws were so tiny that it becomes very unlikely that T. Rex could have used them for hunting or used them to bring food to his mouth. “We don’t know why he needed these small paws,” University of Kansas paleontologist David Burnham said honestly.
Tyrannosaurus has the strongest bites of any animal
A 2011 study of the massive skull of the Tirex, published in the journal Biology Letter, showed that this dinosaur's bite could rightfully be considered the most powerful of the bites of all animals that have ever lived on Earth. These figures reached an impressive figure - 12,814 pounds-force (57,000 Newtons).
Tirex had the strongest and sharpest teeth, the largest of which reached 12 inches in length. But according to a 2012 study published in the journal Earth Sciences, not all teeth performed the same function. In particular, the front teeth of the dinosaur grabbed food, the side teeth tore it apart, and the back teeth already grinded and sent pieces of food further along the alimentary tract. It should be noted that the front teeth were flat and fit much closer together than the side teeth. This ruled out the possibility of breaking a tooth during the capture of the victim, when she was still trying to resist and escape.
Who did the Tyrannosaurus prey on?
This is a huge predator that primarily preyed on herbivorous dinosaurs, including Edmontosaurus and Triceratops. "Hunting constantly, this predator has eaten hundreds of pounds of meat over the course of its life," Burnham said.
“It is possible that Tirex shared his prey, but did so reluctantly,” Burnham said. "He had a hard life, he was constantly hungry and therefore hunted all the time." Note: dragonflies also have to hunt all the time, you can read about this in the article about dragonflies.
“Over the years, evidence has been collected that The main occupation of the Tyrannosaurus was hunting for food.. All of them were indirect and were based only on bite marks, on fallen teeth found near the remains of other dinosaurs, as well as the presence of traces and even entire hunting trails of Tyrannosaurus rex,” Burnham said. But in 2013, in the official journal Proceedings of the National Academy of Sciences, Burnham and his colleagues finally presented direct evidence of the predatory nature of the Tirex. They found a Tyrannosaurus rex tooth stuck between the tail vertebrae of a duck-billed dinosaur. Moreover, the victim managed to get away from Tirex, and over time, this wound with a tooth healed.
"We found a smoking gun!" Burnham says. “Thanks to this discovery, we now know for sure that the monster from our dreams really existed.”
In the journal PLoS ONE in 2010, the results of analyzes of deep bites and cuts received from Tyrannosaurus rex teeth were published. Yet it is not clear whether Tyrannosaurs were subject to cannibalism, fighting to the death with other relatives, or simply eating their remains.
Scientists are sure that Tyrannosaurus hunted both alone and together with other dinosaurs. In 2014, footprints were discovered in the Rocky Mountains of British Columbia that belonged to three dinosaurs from the Tyrannosaurus rex family. Presumably these were Albertosaurus, Gorgosaurus and Daspletosaurus. A study published in the journal PLoS ONE states that at least relatives of T. rex hunted in packs.
In what places and at what time did Tirex live?
Dinosaur fossils can be found in various rocks belonging to the Maastrichtian stage of the late Cretaceous period, which was about 65-67 million years ago, at the end of the Mesozoic era. Tyrannosaurus was one of the last dinosaurs to did not evolve into birds, and lived until the Cretaceous-Paleogene extinction, during which the dinosaurs disappeared.
Tyrannosaurus Rex, unlike other terrestrial dinosaurs, constantly roamed the entire western part North America, which at that time was a huge island - Laramidia. According to National Geographic, more than 50 Tirex skeletons have been discovered, some of them very well preserved. Even the remnants of skin and muscles are visible on them.
The fossil hunter Barnum Brown discovered the first partial skeleton of a Tyrannosaurus Rex at Hell Creek (Montana) in 1902 and some time later sold it to the Carnegie Museum of Natural History in Pittsburgh. Other Tyrannosaurus rex remains are at the American Museum of Natural History in New York.
In 2007, scientists discovered the footprint of T. Rex in Hell Creek and published this discovery in the journal Palaios. But if this print really belongs to a Tyrannosaurus Rex, then it will be the second one that paleontologists have found. The first trace was discovered in 1993 in New Mexico.
History of study
general description
The front two-toed limbs are relatively small in comparison with the powerful legs. The tail is long and heavy. The spine consists of 10 cervical, 12 thoracic, five sacral and about 40 tail vertebrae. The neck, like that of other theropods, is S-shaped, but short and thick to support a massive head. Some bones of the skeleton have voids, thus reducing the overall mass of the body without significant loss of strength. The body weight of an adult tyrannosaurus reached 6-7 tons, the largest individuals (Sue) could weigh about 9.5 tons.
The largest known Tyrannosaurus skull is 1.53 m long. There is a fragment of the jaw (UCMP 118 742), the length of which could be 1.75 meters, the estimated weight of the owner of such a jaw could reach 12 - 15 tons. The shape of the skull differs significantly from that of theropods from other families: it is extremely wide at the back, and the skull is strongly narrowed at the front. According to experts, with such a structure of the skull, tyrannosaurs had excellent binocular vision. The structural features of the skull bones in the tyrannosaurid family make their bite incomparably more powerful than other theropods. The tip of the upper jaws is U-shaped (in most other carnivorous theropods it is V-shaped), which increases the volume of meat and bones that a Tyrannosaurus rex can tear off in one bite, albeit at the expense of additional load on the front teeth.
Tyrannosaurus rex teeth vary in shape. D-shaped in cross section, the anterior teeth fit snugly together. They are bent inside the mouth and reinforced with ridges on the back side. The location and shape of the front teeth reduce the risk of them being pulled out during biting and tugging. The inner teeth are more banana-shaped than dagger-shaped. They are more widely spaced, but also have ridges that reinforce strength on the back side. The full (including the root) length of the largest tooth found is estimated at 30 cm. This is the longest tooth found among all carnivorous dinosaur teeth.
Tyrannosaurus rex moved on its hind limbs, like other members of the tyrannosaurid family.
A tyrannosaurus rex running at 5 m/s needs almost 6 liters of oxygen gas per second, which also leads to the idea that tyrannosaurus rex is warm-blooded.
Evolution
At about the same time as the tyrannosaurus, an almost indistinguishable species lived on the territory of present-day Asia - tarbosaurus. Tarbosaurs had a slightly more elegant structure and slightly smaller sizes.
Feeding method
It has not been definitively established whether tyrannosaurs were carnivores or whether they fed on carrion.
Many large herbivorous dinosaurs had protection on their backs, which indicates the danger of being attacked by a high predator with powerful jaws.
Tyrannosaurs are predators and scavengers. Many scientists believe that tyrannosaurs could have had a mixed diet, like, for example, modern lions - predators, but can eat the remains of animals killed by hyenas.
Way to travel
The mode of movement of the tyrannosaurus rex remains a controversial issue. Some scientists are inclined to the version that they could run, reaching a speed of 40-70 km / h. Others believe that tyrannosaurs walked, not ran.
“Apparently,” writes HG Wells in the famous “Outlines of the History of Civilization,” “tyrannosaurs moved like kangaroos, relying on a massive tail and hind legs. Some scientists even suggest that the Tyrannosaurus rex moved by jumping - in this case, it must have had absolutely incredible muscles. A jumping elephant would be much less impressive. Most likely, the tyrannosaurus hunted herbivorous reptiles - the inhabitants of the swamps. Half immersed in liquid swamp mud, he pursued his victim through the channels and lakes of swampy plains, such as the current Norfolk swamps or the Everglades swamps in Florida.
Opinion about bipedal dinosaurs - the likeness of kangaroos was widespread until the middle of the 20th century. Examination of the tracks, however, showed no tail prints. All carnivorous dinosaurs kept their body horizontal when walking, the tail served as a counterweight and balancer. In general, the tyrannosaurus is close in appearance to a huge running bird.
Phylogenesis
Recent studies of proteins found while examining a fossil T. rex femur have shown dinosaurs to be closely related to birds. Tyrannosaurus is descended from small carnivorous dinosaurs of the late Jurassic era, not from carnosaurs. The currently known small ancestors of Tyrannosaurus (such as the dilong from the Early Cretaceous of China) were feathered with fine, hair-like feathers. The Tyrannosaurus rex itself may not have had feathers (known impressions of the skin of the thigh of a Tyrannosaurus rex bear a pattern of polygonal scales typical of dinosaurs).
Tyrannosaurus in popular culture
Thanks to huge size, huge teeth and other impressive attributes, in the 20th century, the tyrannosaurus rex became one of the most recognizable dinosaurs in the world. That is why he often became a "super monster" - a killer dinosaur in films such as The Lost World, King Kong, etc. The main and most memorable film with the participation of a tyrannosaurus is Steven Spielberg's Jurassic Park, where this character has undergone careful study and therefore looked very impressive.
In the sequel - the film "Jurassic Park 2" - there was already a whole family of tyrannosaurs - a male and a female with a cub, which significantly reduced their negative role; moreover, the tyrannosaurs' pursuit of the film's characters, and then the rout perpetrated by the male tyrannosaurus on the streets of San Diego, was justified to some extent by their parental instinct and desire to save their cub.
Ultimately, in the movie Jurassic Park 3, the developers needed a new dinosaur to play the role of the main villain, and their choice fell on the Egyptian spinosaurus. The Tyrannosaurus Rex himself appeared in the film only sporadically.
Tyrannosaurus Rex is featured in many documentaries such as Walking with Dinosaurs, The Truth About Killer Dinosaurs, etc. It was most accurately represented in the series documentaries"Dinosaur Battles"
The image of a tyrannosaurus rex "rooted" in cartoons as well. Under the name "Sharptooth", the tyrannosaurus appears as the main negative character in the popular series of American full-length cartoons "The Land Before Time", actors which are the dinosaurs.
Tyrannosaurus also became a character in a number of animated series about transformers. So, in his "image and likeness" Trypticon was created - a colossal transformer, a city-fortress of the Decepticons. He is also the "mount" of Zadavala, the commander of the "Fighting Dinosaurs" squad in the Transformers: Victory series. The leader of the predacons Megatron in the TV series "Beast Wars" transforms into a tyrannosaurus rex (as the most terrible earthly creature), when the transformers, once on the prehistoric Earth, take on the appearance of terrestrial animals - both living and extinct. However, the guise of a tyrannosaurus is taken not only by carriers of an evil inclination: Grimlock, the commander of a group of Dinobots, is also transformed into a tyrannosaurus rex - not particularly smart, but powerful robotscreated by the Autobots and fighting with them against the Decepticons.
Tyrannosaurus is also seen in the Dino Crisis series of games. In Dino Crisis, he is the strongest dinosaur (as well as in Dino Stalker) throughout the game, and in Dino Crisis 2, only at the end of the game, the tyrannosaurus presumably dies in the fight against the giganotosaurus, which is represented in the game by a much larger one (length over 20 meters) than is known from fossil remains. computer game ParaWorld, the Tyrannosaurus Rex is the strongest unit in the Desert race and the strongest unit in the game. In the game, the Tyrannosaurus Rex is much larger than in reality.
Notes
- Erickson, Gregory M.; Makovicky, Peter J.; Currie, Philip J.; Norell, Mark A.; Yerby, Scott A.; & Brochu, Christopher A. (2004). "Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs". Nature 430 (7001): 772–775. DOI:10.1038/nature02699.
- Brochu Christopher A. Osteology of Tyrannosaurus Rex: Insights from a Nearly Complete Skeleton and High-resolution Computed Tomographic Analysis of the Skull. - Northbrook, Illinois: Society of Vertebrate Paleontology, 2003.
- see en:Denver Formation
- see en:Lance Formation
- Breithaupt, Brent H.; Elizabeth H. Southwell and Neffra A. Matthews (2005-10-18). "In Celebration of 100 years of Tyrannosaurus Rex: Manospondylus gigas, Ornithomimus grandis, and Dynamosaurus Imperiosus, the Earliest Discoveries of Tyrannosaurus Rex in the West" in 2005 Salt Lake City Annual Meeting . Abstracts with Programs 37 : 406, Geological Society of America. Retrieved 2008-10-08.
- , p. 81-82
- , p. 122
- , p. 112
- , p. 113
- , - Northern State University:: Aberdeen, SD
- Montana State University (2006-04-07). Museum unveils world "s largest T-rex skull. Press release . Retrieved 2008-09-13.
- Mickey Mortimer (2003-07-21). And the Largest Theropod Is..... Press release . Retrieved 2012-04-20.
- Stevens, Kent A. (June 2006). "Binocular vision in theropod dinosaurs" (PDF). Journal of Vertebrate Paleontology 26 (2): 321–330. DOI:10.1671/0272-4634(2006)262.0.CO;2.
- Jaffe, Eric (2006-07-01). "Sight for" Saur Eyes: T. rex vision was among nature "s best". science news 170 (1): 3. DOI:10.2307/4017288. Retrieved 2008-10-06.
- Holtz, Thomas R. (1994). "The Phylogenetic Position of the Tyrannosauridae: Implications for Theropod Systematics". Journal of Palaeontology 68 (5): 1100–1117. Retrieved 2008-10-08.
- Paul, Gregory S. Predatory dinosaurs of the world: a complete illustrated guide. - New York: Simon and Schuster, 1988. - ISBN 0-671-61946-2 Pattern:Pn
- Sue's vital statistics. Sue at the Field Museum. Field Museum of Natural History. (unavailable link - history) Retrieved September 15, 2007.
- All large dinosaurs were warm-blooded
- Mutant Tyrannosaurus rex fossil found in Mongolia
- T. rex, Meet Your Great-Grandfather Science Magazine September 17, 2009
- El antepasado enano del Tiranosaurio Rex El Mundo.es September 17, 2009 (Spanish)
- Denver W. Fowler, Holly N. Woodward, Elizabeth A. Freedman, Peter L. Larson, & John R. Horner. Reanalysis of "Raptorex kriegsteini": A Juvenile Tyrannosaurid Dinosaur from Mongolia // PloS ONE. - 2011. - Vol. 6. - No. 6. - PMID 21738646.
- Horner, J.R. and Lessem, D. (1993). The Complete T. rex : How Stunning New Discoveries Are Changing Our Understanding of the World's Most Famous Dinosaur. New York: Simon & Schuster.
- Sue at The Field Museum
- David W.E. Hhone and Mahito Watabe. New information on scavenging and selective feeding behavior of tyrannosaurs. (PDF)
- Tyrannosaurus Rex recognized as a cannibal (Russian). Membrana (October 19, 2010). Archived from the original on August 28, 2011. Retrieved October 19, 2010.
Tyrannosaurus, who lived in the Cretaceous period, had a body length of about 14 m; he lived in Asia, North America; it is the largest carnivorous land animal ever.
The largest was the Tyrannosaurus rex, 5-6 meters high and 12 m long. Its mouth was 1 m long. In one sitting, it could swallow prey weighing 200 kg. Tyrannosaurs - the most terrible land predators in the history of the planet. Adults weighed about 5-6 tons, and therefore were 15 times heavier than the largest modern predator - polar bear. The dinosaur that roamed the Earth 65 million years ago was the largest land predator of all time.
How many years did tyrannosaurs live?
Tyrannosaurus rex - the most terrible land predators in the history of the planet - died young. The predator grew rapidly, gaining two kilograms a day, like a modern African elephant. How did they manage to grow to such a size? Some experts believed that they grew slowly all their lives, others that they grew rapidly in their youth, and then the rate of increase in size slowed down, like in birds and mammals. that all these creatures were between two and 28 years old at the time of death. Animals grew the most at the age of 14-18 years of their life, subsequently maintaining the achieved size.
Feathered tyrannosaurus
Ancestors tyrannosaurus rex were covered with small feathers, not bare skin. The ancestral skeleton, about 130 million years old, is the oldest representative of the genus of tyrannosaurs, and so far the only one whose "featheredness" is not in doubt among paleontologists. He was about a meter and a half from the nose to the tip of the tail. However, he walked on his hind legs and was a formidable predator - for smaller herbivorous dinosaurs. The tyrannosaurus itself was hardly covered with feathers - they would have interfered with it more than helped, because of its large size, it was more important for it to give off excess heat to the outside world so as not to overheat. However, his "chicks" could hatch from eggs, covered with some kind of fluff, and lose it as they grow older Slow predators
Most large predator in the world of dinosaurs, was probably quite slow.
The Tyrannosaur rex could not reach speeds of more than 40 km/h, although many scientists believe that it was able to run almost twice as fast. Scientists made their conclusions on the basis of a computer model of a six-ton lizard.
What did tyrannosaurs eat?
The size of the tyrannosaurs was a problem for these animals - becoming larger, they most likely gradually lost the ability to move quickly. Young small animals could reach speeds of up to 40 kilometers per hour, but as soon as the weight became more than a ton, this became impossible for biomechanical reasons. So if this animal was a predator and not a scavenger, it is a mystery how it managed to get enough food to maintain a gigantic body growth rate. Perhaps the Jurassic ecosystem produced enough carrion that the tyrannosaurs simply did not need to actively hunt. There was plenty of fall around. It is still unclear whether the tyrannosaurs were predators, or whether they fed mainly on carrion?
powerful bite
Tyrannosaurus did not just sink its teeth into the body of the victim, as, say, lions do today. He quickly and easily bit through muscles, cartilage and even thick bones to a great depth, and then pulled out large pieces of flesh from the victim. The ground bones were eaten along with the meat. Tyrannosaurus rex had a very strong skull and jaw. And the most amazing thing is that the monster also had a whole shock absorption system. In particular, unlike most animals, some of the bones that make up the skull of the tyrannosaurus retained some mobility relative to each other. Connective tissues helped to dissipate the impact energy. Of course, its sharp 15-centimeter teeth also contributed to this way of feeding the tyrannosaurus.
Tyrannosaurus rex is the largest predator dinosaur that lived in North America at the end of the Cretaceous period (68-65 million years ago).
Appearance description
Tyrannosaurus fully corresponded to its characteristic - the largest one. The body length was almost 13 meters, the height could reach 3.5-4 m, and the weight was almost 8 tons.
The skeleton of a T-Rex consists of 299 bones, of which 58 are reserved for the skull. The spine contains 10 cervical, 12 thoracic, 5 sacral, 40 tail vertebrae. The neck, like that of many other theropods, was S-shaped, but at the same time it was short and thick, which served as an adaptation for holding a large head. Another feature of tyrannosaurs was hollow bones, which contributed to a decrease in the total body weight without losing strength.
The shape of the skull was different from other theropods: it was wide at the back and narrowed at the front. Thanks to this, the dinosaur's eyes looked forward, and not to the side. Consequently, T. rexes had developed binocular vision.
The forelimbs are small, with 2 active fingers. Hindquarters - strong and powerful with 3 toes. The theropod tail was long and extremely heavy.
Due to the peculiarity of the structure of the skull, tyrannosaurs had a powerful bite. The teeth were different in shape. The D-shaped ones fit snugly together, were bent inward and had small notches, and this reduced the risk of tearing when biting and jerking.
The inner teeth were banana-shaped. Widely spaced, they increased the strength of the entire jaw.
The length of one tooth, together with the root, found among the rest of the remains, is approximately 31 cm.
The running speed of the Ti-rex still causes heated discussions, since the indicator of the mass that the hind limb could withstand remains unknown. Some experts believe that tyrannosaurs had the most developed and voluminous leg muscles.
But studies conducted in 2002 found that theropods could have traveled no more than 40 kilometers per hour. And studies in 2007 showed a figure of 29 km per hour.
Tyrannosaurus rex nutrition
It is believed that T. rex were carnivorous predators, but the studied remains do not allow us to give an exact answer how they got food. There is a theory that tyrannosaurs cannot be considered ruthless and cold-blooded killers, since their only weapon was a powerful jaw. Yes, and poorly developed forelimbs and a huge body did not allow him to destroy everyone and everything.
There are 2 versions that describe the methods and types of feeding of theropods.
scavenger
This version is based on studies of the found remains of tyrannosaurs: most likely, they not only did not disdain the carcasses of their dead brothers, but also ate them with great pleasure. There are several facts in favor of this theory:
- massive body, weighing more than one ton, did not allow the Ti-rex to engage in long pursuits and tracking down prey.
- CT scan. With the help of the study of the restored dinosaur brain, it was possible to study in more detail the functionality and structural features of the “inner ear”, which is responsible not only for hearing. Tyrannosaurus rex had an "inner ear" different in structure from other dinosaurs, which were considered dexterous hunters.
- Vertebral studies. The giant lizard had some limitations in movement: maneuverability and agility were not its strengths.
- Teeth. The structure of the ti-rex's teeth suggests that they are adapted for crushing and grinding bones, extracting a large number food from the remains, including bone marrow. As a rule, the teeth of dinosaurs that ate fresh meat were more fragile: after all, they simply ate the body.
- slowness. The size of the tyrannosaurus harmed its owner: when falling, the lizard could damage or break the ribs or legs. Slow reaction and sluggishness, short forelimbs and two fingers did not help hunting.
Based on all of the above facts, scientists have come to the conclusion that the tyrannosaurus was a scavenger.
Hunter
The previous version with the scavenger T-rex has a fairly strong justification, but some paleontologists tend to think that the giants were hunters. And the following facts speak in favor of this version:
- Powerful Bite. His strength allowed the T-rex to break any bones.
- herbivorous dinosaurs. It is possible that the main prey of theropods were torosaurs, triceratops, anatotitans and others. Due to its size, the giant lizard could not pursue its victims. With binocular vision, Tyrannosaurus could presumably be able to judge the distance between itself and its prey, attacking with a single dash from an ambush. But, most likely, the choice fell on cubs or old and weakened dinosaurs.
The theory stating that the theropod was a hunter has one caveat: the T-Rex still did not disdain the remains of dead dinosaurs.
It is known that tyrannosaurs were loners, hunting exclusively in their territory.
But, of course, skirmishes happened.
If one of them died, the giant ate the meat of the deceased relative.
It turns out that if the ti-rex was not a pure scavenger.
You can also call him a hunter with a stretch: he could still eat dead carcasses or take food from other dinosaurs.
Luckily the size allowed it.
Reproduction of t-rex
Adult theropods were solitary. The territories on which they could hunt were measured in hundreds of km2.
When mating is necessary, the female called the male with a characteristic roar. But even here it was not easy. The courtship process took time and effort.
The female tyrannosaurs were much larger and more aggressive than the males.
In order to gain favor, the males had to bring the carcass of some pangolin as a treat.
The mating process itself was short-lived. After him, the male ti-rex went in search of food or other females, and the fertilized female was preparing to become a mother: she built a nest for laying eggs.
A few months later, the female theropod laid about 10-15 eggs.
Fossilized tyrannosaurus eggs
But the nest was located directly on the ground, and this was extremely risky: after all, small predators could eat the postponed offspring.
For the purpose of protection and protection, the female did not leave the eggs for 2 months.
After a couple of months, offspring hatched from the laid and carefully guarded eggs.
As a rule, only 3-4 cubs appeared from the entire brood.
This is due to the fact that during the Late Cretaceous period, in which tyrannosaurs existed, the atmosphere was filled with gases due to volcanic activity.
They adversely affected the development of the embryo, destroying it from the inside. Thus, T-Rex were already doomed to death.
History of finds
Fossils were first found at Hell Creek, Montana in 1900. The expedition was organized by the American Museum of Natural History and led by B. Brown.
The remains obtained during this expedition were described by Henry Osborn in 1905. Then he attributed the tyrannosaurus rex to Dynamosaurus imperiosus.
A reconstructed specimen of a Tyrannosaurus rex obtained by B. Brown in 1902-1905.
1902: Fossil remains of a partial skeleton and an incomplete skull ( AMNH 973), the bones were extracted for three years.
Henry Osborn in 1905 described these fossils as Tyrannosaurus rex, and then the first remains were recognized Tyrannosaurus rex.
1906: The New York Times publishes an article about the first T-Rex.
A partial skeleton of huge bones from the hind limbs and pelvis has been installed in the American Museum.
1908: B. Brown discovered an almost complete specimen with a skull. G. Osborne described it in 1912.
1915: The first reconstruction of a complete Tyrannosaurus Rex skeleton appears at the American Museum of Natural History, with one drawback: the T-rex's arms replaced the Allosaurus's three-toed limbs.
1967: W. McManis, archaeologist, University of Montana, discovered the skull. The instance was given a number MOR 008. Scattered bones of an adult lizard were also found.
1980: The "black beauty" is found. black beauty got its name from the dark color of the remains. J. Baker discovered a large bone on a river bank in Alberta. For a whole year, the excavations of the entire ti-rex lasted. The sample is displayed in Royal Tyrrell Museum in Drumheller, Alberta, Canada.
1988: Cathy Wankel, a farmer, found bones sticking out of the ground in the sediments of Hell Creek (island national reserve Montana).
The specimen was only recovered in 1990 by a team at the Museum of the Rockies led by Jack Horner.
It includes about half of the skeleton. It was here that the full forelimbs of theropods were first discovered.
This sample is called Wankel Rex (MOR 555). He was about 18 years old at the time of his death. Adult but underachieving maximum dimensions dinosaur. These are the first fossils to contain biological molecules in their bones.
1987: Tyrannosaurus, nicknamed Sten. Discovered by Stan Sacrison in Hardling County, South Dakota. The excavations were completed in 1992. The remains were originally thought to be those of a Triceratops.
In 1993 and 2003, additional "Wall" bones were found. The length of its body is 12 meters, the length of the skull is 1.3 m. Moreover, the Ti-rex had many pathologies: broken ribs, fused cervical vertebrae, holes in the back of the head from the teeth of relatives.
Real skull "Sue"
1990: Sue Hendrickson was lucky enough to discover the largest complete specimen of a Tyrannosaurus Rex.
The remains are 73% complete. The length is 12.5 meters, the skull is 1.5 m.
1998-99: preparation and thorough cleaning of the found remains.
2000: The skeleton is completely assembled and presented to the public.
The study of "Sue" showed that the individual was about 28 years old at the time of death. And it reached its maximum size by the age of 19.
1998: found t-rex " Bucky". It was found along with the bones of Edmontosaurus and Triceratops. Bucky is the first giant to have a "fork" in his bones - fused collarbones in the shape of a "fork".
Skeleton "Sue"
Its dimensions were: 29 cm wide and 14 cm high.
"Fork" is the link between dinosaurs and birds.
2010: Tyrannosaurus rex skeleton discovered Tristan Otto". Carter County, Montana.
The excavations were completed in 2012, after which the bones were cleaned and processed for 2 years.
49% were recovered with a complete skull.
The individual died at the age of 20. The body length was 12 m, height - 3.5 m, weight -7 tons.
2015: A copy of " Rees Rex". Hell Creek, northeastern Montana.
Recovered 30% of the skeleton and a well-preserved skull, which is considered the most complete T-rex skull ever recovered.
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").Time of residence: about 67-65.5 million years ago in last century 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 Tyrannosaurus Rex had the strongest bite force of any land animal that has 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 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 speak of 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. In the era of the Maastrichtian century, this area was subtropical, with warm and humid climate. The flora is represented mainly by flowering plants, met 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.
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