Tell about Tyrannosaurus ?

One feature of Tyrannosaurus rex that everyone makes fun of is its arms, which seem disproportionately tiny compared to the rest of its massive body.

The M. gigas remains were, in 1907, identified by Hatcher as those of a theropod rather than a ceratopsid. Henry Fairfield Osborn recognized the similarity between Manospondylus gigas and Tyrannosaurus rex as early as 1917, by which time the second vertebra had been lost.

The name Tyrannosaurus rex means "king of the tyrant lizards": "tyranno" means tyrant in Greek; "saurus" means lizard in Greek, and "rex" means "king" in Latin. In 1905, Henry Fairfield Osborn, president of the American Museum of Natural History at the time, named Tyrannosaurus rex.

T. rex's arms were over three feet long, however, and may have been capable of bench pressing 400 pounds each. In any event, T. rex didn't have the smallest arm-to-body ratio among carnivorous dinosaurs; that was the Carnotaurus, whose arms looked like tiny nubs.

Aside from Tyrannosaurs, other Tyrannosaurid genera include Albertosaurus, Alectrosaurus, Alioramus, Chingkankousaurus, Daspletosaurus, Eotyrannus, Gorgosaurus, Nanotyrannus (a controversial genus that might, in fact, be an adolescent T. rex), Prodeinodon, Tarbosaurus and Zhuchengtyrannus.

The dinosaurs of the Mesozoic Era obviously didn't brush their teeth or floss. Some experts think shards of rotten, bacteria-infested meat constantly lodged in its closely packed teeth gave Tyrannosaurus rex a "septic bite," which infected and eventually killed its wounded prey.

Owing to the fragmentary nature of the Manospondylus vertebrae, Osborn did not synonymize the two genera, instead considering the older genus indeterminate. In June 2000, the Black Hills Institute found around 10% of a Tyrannosaurus skeleton (BHI 6248) at a site that might have been the original M. gigas locality.

There's good reason to believe, based on fossils and the shapes of their hips, that female T. Rexes outweighed males by a few thousand pounds. The likely reason for this trait, known as sexual dimorphism, is that females had to lay clutches of T. rex-size eggs and were blessed by evolution with bigger hips.

T. rex fossils are found in western North America, from Alberta to Texas. But it's possible that T. rex was an invasive species from Asia, according to a 2016 study published in Scientific Reports.

It's difficult to infer a dinosaur's life span from its fossils, but based on analysis of existing specimens, paleontologists speculate that Tyrannosaurus rex may have lived as long as 30 years.

An analysis of T. rex's skeletal features showed that the dinosaur king was more similar to two Tyrannosaurs in Asia, Tarbosaurus and Zhuchengtyrannus, than it was to North American Tyrannosaurs, the researchers told Live Science.

Barnum Brown, assistant curator of the American Museum of Natural History, found the first partial skeleton of Tyrannosaurus rex in eastern Wyoming in 1900. Brown found another partial skeleton in the Hell Creek Formation in Montana in 1902, comprising approximately 34 fossilized bones.

It's difficult to infer a dinosaur's life span from its fossils, but based on analysis of existing specimens, paleontologists speculate that Tyrannosaurus rex may have lived as long as 30 years.

The largest and most complete T. rex skeleton ever found was nicknamed Sue, after its discoverer, paleontologist Sue Hendrickson.

T. rex had strong thighs and a powerful tail, which counterbalanced its large head (Sue's skull is 5 feet, or 1.5 m, long) and allowed it to move quickly. The 2011 study, which also modeled T. rex's muscle distribution and center of mass, suggests the giant could run 10 to 25 mph (17 to 40 km/h), as previous studies had estimated.

Writing at the time Brown said "Quarry No. 1 contains the femur, pubes, humerus, three vertebrae and two undetermined bones of a large Carnivorous Dinosaur not described by Marsh.... I have never seen anything like it from the Cretaceous". Henry Fairfield Osborn, president of the American Museum of Natural History, named the second skeleton Tyrannosaurus rex in 1905.

dinosaur was atop the food chain, it would most likely have died from old age, disease, or hunger rather than attacks by fellow theropods, except when it was young and vulnerable.

Current thinking is that there's no reason Tyrannosaurus rex couldn't have done both, as would any carnivore that wanted to avoid starvation.

The generic name is derived from the Greek words τύραννος (tyrannos, meaning "tyrant") and σαῦρος (sauros, meaning "lizard"). Osborn used the Latin word rex, meaning "king", for the specific name. The full binomial therefore translates to "tyrant lizard the king" or "King Tyrant Lizard", emphasizing the animal's size and perceived dominance over other species of the time. Osborn named the other specimen Dynamosaurus imperiosus in a paper in 1905.

Its two-fingered forearms were puny, making it unlikely that T. rex could use them to kill or even get a meal to its mouth. However, it's possible that T. rex had such tiny arms because of its powerful bite, according to research from Michael Habib, an assistant professor of clinical cell and neurobiology at the University of Southern California and a research associate at the Dinosaur Institute at the Natural History Museum of Los Angeles County.

Neck and arms muscles compete for space in the shoulder, and it appears that the neck muscles edged out the arm muscles in T. rex's case, according to Habib's research. Moreover, long arms can be broken, are vulnerable to disease, and take energy to maintain, so having short arms may have been beneficial to the king in the long run, Habib's research shows.

In 1906, Osborn recognized that the two skeletons were from the same species and selected Tyrannosaurus as the preferred name.

T. rex, were covered in feathers at some point during their lives, most likely when they hatched, a conclusion supported by the discovery of feathered Asian tyrannosaurs such as Dilong and the almost T. rex-size Yutyrannus.

In 1996, a team of Stanford University scientists examining a T. rex skull determined that it chomped on its prey with a force of 1,500 to 3,000 pounds per square inch, comparable to that of a modern alligator.

More recent studies put that figure in the 5,000-pound range. (The average adult human can bite with a force of about 175 pounds.) T. rex's powerful jaws may have been capable of shearing off a ceratopsian's horns.