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Tyrannosaurus Rex: 5 Facts About the Tyrant Lizard King

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Around 90 million years ago lived one of the most ferocious predators ever to have walked the earth.

Tyrannosaurus Rex, which means "Tyrant Lizard King" reigned supreme during the Late Cretaceous Period (90 to 66 million years ago).

It's a classic movie monster, but unlike most other movie monsters, the T Rex actually existed. It excites and fascinates us to know there was a time when this fearsome giant roamed the forests and plains of North America.

Here are five facts about the Tyrannosaurus Rex.

1. It had the most powerful bite of any land animal in history

The Tyrannosaurus Rex had a maximum bite force of 12,800 pounds, powerful enough to crush a car.

This seems to have been its primary predatorial asset. Its arms were too small to be of much use, and although it had muscular thighs, it couldn't run very fast. So it probably relied on its mighty jaws to take down prey. One bite would have wounded its target so deeply as to make escape unlikely.

Its lack of speed has led some to suggest that the T Rex was an ambush predator. Alternatively, it may have hunted large herbivores that were just as slow.

2. It was cannibalistic

Fossil evidence indicates that the only dinosaur that could hunt a T Rex was another T Rex.

Only one other dinosaur species, the Majungatholus, is known to have fed on its own kind.

"If I was a tyrannosaur facing another tyrannosaur face-to-face, I'd say the only real strategy is to wait for an opening and then go straight for the head," says researcher Nicholas Longrich.

This also supports the theory that the Tyrannosaurus Rex was a solitary animal that hunted alone rather than in packs.

3. There was a long-running debate about whether it was a hunter or scavenger

The debate centred around the T Rex's anatomy. Many researchers didn't believe that such a slow, tiny-armed dinosaur could be an effective predator.

This led some to conclude that the Tyrannosaurs Rex was the tyrant king of leftovers rather than lizards. Thankfully, fossil evidence appears to have rescued the its fearsome reputation.

In a 2013 study, University of Kansas palaeontologist David Burnham unveiled a duckbill dinosaur fossil with a T Rex tooth embedded in its tail bone. The bone around the tooth mark had healed, indicating that the dinosaur had been alive when it was attacked and that it had managed to escape.

"We found the smoking gun!" Burnham said. "With this discovery, we now know the monster in our dreams is real."

The prevailing theory nowadays is that the T Rex was an opportunistic feeder that would scavenge or hunt depending on what was available.

But it could not have relied solely on scavenging or it would have gone extinct, as there were much smaller scavenger species that were quicker and could cover more ground. Most carcasses would have been consumed before the T Rex could reach them.

Tyrannosaurus rex holotype specimen at the Carnegie Museum of Natural History, Pittsburgh.

Tyrannosaurus rex holotype specimen at the Carnegie Museum of Natural History, Pittsburgh.

4. The first T Rex fossil was discovered in 1902

Famous fossil hunter Barnum Brown discovered the first Tyrannosaurus Rex skeleton in Hell Creek, Montana. "There is no question but what this is the find of the season," he wrote to his boss. Six years later, he uncovered an almost complete T Rex skeleton, currently on display at the American Museum of Natural History.

In 1990, Susan Hendrickson uncovered the largest-ever Tyrannosaurus rex skeleton yet to be found. The skeleton is 90% complete and is currently on display at the Field Museum in Chicago.

5. It was a relatively smart dinosaur

An analysis of the Tyrannosaurus Rex skull indicates that it contained a large brain compared to other species of dinosaurs around at the time. Palaeontologist Dr. Steve Brusatte claims in his book The Rise and Fall of the Dinosaurs that the T Rex was as smart as a chimpanzee.

Brusatte also points out that, as much as we all love Jurassic Park, the idea that the T Rex couldn't see you if you stood still is not supported by the evidence. It was smart enough to see through such a trick. Furthermore, the size of its olfactory bulb suggests a sense of smell comparable to bloodhounds.

The Cretaceous Period was the last of the three periods of the Mesozoic Era. It lasted from about 145 to 66 million years ago.

The Cretaceous Period was the last of the three periods of the Mesozoic Era. It lasted from about 145 to 66 million years ago.

More Facts about the Tyrannosaurs Rex

  • Height 12 feet
  • Length 40 feet
  • Type of dinosaur Theropod (characterised by hollow bones and three-toed limbs). The group includes all flesh-eating dinosaurs.
  • Average lifespan 30 years.
  • Habitat The forests and floodplains of North America and Asia (both of which were still part of the supercontinent Pangaea at the time).
  • Tooth size The largest T Rex tooth yet discovered is 12 inches (30 cm) long.


Joseph Castro. 2017, 17 October. Tyrannosaurus Rex: King of the Dinosaurs (

Riley Black. 2012. The Tyrannosaurus Rex’s Dangerous and Deadly Bite (

Jennifer Viegas. 2010, 15 October. Tyrannosaurus Rex Was a Cannibal (

Christopher Joyce. 2011, 14 September. Bone To Pick: First T. Rex Skeleton, Complete At Last (

Dr Stephen Brusatte. 2018, 27 November. How brains, not brawn, helped the Tyrannosaur become king (

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.