Was Tyrannosaurus rex a Ferocious Predator or a Wimp?

Tyrannosaurus rex is the most famous dinosaur in the world: beloved by paleontologists and the public alike (especially kids). How T. rex lived is one of the most hotly debated topics in dinosaur research. T. rex was the largest predator in its ecosystem with a powerful and (possibly) poisonous bite. It has been suggested, however, that T. rex was a scavenger, like the dinosaurian equivalent of a vulture, rather than an active predator. The aim of this article is therefore to examine the behavior and lifestyles of these incredible animals and to provide you with clues on whether T. rex was a predator.


INTRODUCTION
Tyrannosaurus rex is the most famous and most beloved dinosaur on the planet. The genus Tyrannosaurus only contained a single species, T. rex. The name T. rex appropriately translates to Tyrant Lizard King. The first T. rex skeleton was unearthed by Barnum Brown in and was described and named by Henry Fairfield Osborn years Figure   Figure Drawing of a T. rex skull compared to that of a human.
later [ ]. T. rex was the largest predator in North America during the PREDATOR A meat-eating animal that kills its own prey.
Late Cretaceous-the last period in which dinosaurs (not including

CRETACEOUS
The final period of the Mesozoic (which also included the Triassic and Jurassic) which lasted from to million years ago. birds) lived-between and million years ago. Much of what we know about T. rex comes from the mid-western United States. T. rex was a theropod (the group of predominantly meat-eating dinosaurs) that could reach up to m (or feet) in length and could have weighed as much as metric tons, which is much more than an African Elephant bull!

A GIANT SKULL WITH THE BITE EVER
The most striking feature of Tyrannosaurus is their giant skulls which could reach a colossal . m ( ft) in length ( Figure ). It is thought that T. rex had the strongest bite force of any land animal that has ever lived. Computer simulations based on the shape and strength of T. rex's skull showed that its bite force was incredibly powerful. For you to have an idea of how powerful it was, T. rex's bite was up to times stronger than that of most humans [ ].
In contrast to the thin and blade-like teeth of most other theropods (which include Allosaurus, Velociraptor, and even birds), the teeth of tyrannosaurids were oval in cross-section. The thick cross-section of tyrannosaurid teeth shows that they were very strong, and this was confirmed by a -cm coprolite (fossilized poo) from Canada, which was packed with bone fragments. The broad teeth of tyrannosaurids provided structural support to withstand the stresses associated with subduing struggling prey.
It has been hypothesized that tyrannosaurs had septic bites. The shape

SEPTIC BITE
This is when a bite allows bacteria to move from the mouth to a wound which leads to a bacterial infection and eventually blood poisoning-a condition called sepsis. and angle of the spaces between tooth serrations of tyrannosaurids most closely resemble those of Komodo dragons, a species known for their septic bites. Grease and other food particles become trapped between the T. rex's teeth serrations leading to colonization by septic bacteria, meaning that a non-fatal bite by a tyrannosaur would have led to a serious bacterial infection [ ]. However, the tooth serrations are like those found in other theropods, so it would be hard to argue that tyrannosaurs were exceptional in this regard. Besides, because tyrannosaur mostly hunted prey much smaller than themselves, a septic bite would not have made that much di erence to their e ectiveness as a predator.

THE SENSES OF T. REX
T. rex had an amazing sense of smell. We know this because the size of the parts of the brain responsible for smell (the olfactory bulbs) are bigger compared to other theropods suggesting that this was behaviorally important to tyrannosaurs [ ]. T. rex could locate prey over great distances like a Cretaceous vulture.
Their eyes were large for a theropod of its size, and computerized tomography scans of its fossilized brain and skull-which creates thousands of sequential X-ray images along with the fossilized brain and skull-show that the optic nerve, which carries information from the eyes to the brain, is very well-developed. On top of this, the eyes of tyrannosaurs faced forward. This would have given T. rex good depth perception. It could, therefore, judge distances, an adaption common to modern hunters. The size and position of the eyes, as well as brain structure, has led scientists to think that T. rex had eyesight as good as modern-day birds of prey [ ].

THE TINY POWERFUL ARMS OF T. REX
The arms of T. rex were relatively tiny, about the size of a human's, though with di erent proportions and only two fingers (Figure ). There has been much debate about the possible functions of their forelimbs. Rather than being useless, T. rex arms were muscular some estimates able to pull kg ( lbs) as estimated by the size of their biceps-though this is at the higher end of the estimates. This suggests that their arms did serve a purpose, but the exact nature of that purpose is still debated by paleontologists [ ]. They are smaller and with less sharp claws than ancestral tyrannosaurs, so whatever they were doing with their arms, they were doing it less than their forbears.

GROWING UP
Just like how human change as we get older so did dinosaurs. Unlike the large-headed and bulky adults, juvenile T. rex's were di erent with smaller, slender heads, long legs and thinner and more blade-like teeth. So, paleontologists concluded that young tyrannosaurs had a di erent lifestyle than adults. The longer limbs and more slender bodies meant that juveniles could run much faster than the adults, while the smaller skulls and bladed teeth imply that they did not crush bone like the adults.
The classic view of T. rex is that it was a terrifying predator and saying anything else seems almost heretical. In , American paleontologist Jack Horner published an article that suggested that a view of T. rex for over a years should be turned on its head … T. rex, the Tyrant Lizard King, was a scavenger. The theory that T. SCAVENGER A meat-eating animal that finds and eats animals that are already dead. rex and its close relatives were scavengers are based on tooth shape, sense of smell, and the size of the arms [ ]. Many of these points have already been discussed in this paper, so what do you think? Was T. rex a scavenger or a predator?
The best answer is that, like most living carnivores T. rex both! There are good examples in the fossil record of large tyrannosaurs acting as scavengers [ ], but there is definitive evidence of T. rex hunting, or at least trying to. Paleontologists have found several examples of failed attempts of predation where tyrannosaurs have left marks, or even teeth behind in their prey. One good example is seen is a duck-billed hadrosaur-a medium sized plant-eating dinosaurs called Edmontosaurus annectens, and very common during CONCLUSION T. rex was the largest predator in North America during the last million years of the age of dinosaurs. By analyzing the fossil remains of T. rex, paleontologists have discovered much about the behavior of these incredible animals. By studying the strength of their skulls, we know that they had the strongest bite force of any land animal that has ever lived. Although T. rex was an active predator, like most large predators, it also engaged in scavenging behaviors too when the opportunities arose. . doi: . /frym. .

CONFLICT OF INTEREST:
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