Scientists have estimated Tyrannosaurus put on the equivalent of the weight of an elephant each year during its 'teenage' growth spurt.  Weight gain/teenage year: 1790kg (3946lbs) 

The small forelimbs of Tyrannosaurus were tiny, odd looking appendages. We can still only guess at what these forelimbs were used for. Could they have been useful when grasping prey, in some kind of mating ritual or even just to push the dinosaur up if it fell over?

As if Trex wasn't terrifying enough, recent fossil discoveries show that it was also a cannibal. Several Trex bones have been found with tooth marks perfectly matching the teeth of Trex. So even a Trex would have feared Trex!

Surprisingly, fossils of Trex are not very rare. More than half of all dinosaur species are known from only a single fossil, whereas hundreds of specimens of Trex have been discovered over the past century. This rich fossil record allows scientists to study Trex in incredible detail.


Tyrannosaurus rex

"Tyrant Lizard King"


Tyrannosaurus rex was a huge, bipedal, carnivorous dinosaur with a large, heavy skull, long tail, and unusually short forearms.



Tyrannosaurus rex lived during the Late Cretaceous, 66 million years ago.

Extinct for about: 00,000,000,000 Days00 Hours00 Min00 Sec

How old are you?
00,00,00.00 of your lifetimes have passed since their extinction.

They Call it Home

Tyrannosaurus fossils have been found among numerous rock formations in North America, including the famous Hell Creek Formation, which also contains the gigantic pterosaur Quetzalcoatlus, the armoured Ankylosaurus, and the horned dinosaur,Triceratops. T. rex has been found as far south as New Mexico and as far north as Canada.








  • Alberta, Canada
  • Colorado
  • Montana
  • Wyoming

What We Heard About Their Hearing

Human Ear

Tyrannosaurus had excellent hearing and balance. These fearsome creatures would certainly have been able to hear their prey coming. There really would have been no escape. 


What Big Teeth You Have

Dinosaur Tooth

Tyrannosaurus teeth are amongst the largest ever known, measuring 30cm (12in) long including the root. In fact they were the size and shape of a banana - a lethal banana. T. rex jaws were powerful enough to crush bone and extract bone marrow and could open up to 1m wide. 


Nose Knowledge

Human Nose

Tyrannosaurus had large olfactory bulbs and nerves, allowing it to sniff out its prey like a great white shark.


The Poop Scoop

Dinosaur Poop

Tyrannosaurus coprolites (fossilised poo) have been found measuring 2 litres (3.5 pints) in volume. Some T. rex droppings have been found to contain the remnants of Triceratops and Edmontosaurus bones. 


The Most Fantastic Find

Sue the T. rex was named after her discoverer Sue Hendrickson. Sue is one of the largest, most extensive and best-preserved T. rex fossils ever uncovered. She was auctioned for a whopping $8.3 million - the highest ever paid for a fossil. She is now housed within the Field Museum of Natural History in Chicago. Scientists have found that Sue reached the grand old dinosaur age of 28, which would have been about the maximum age for a Tyrannosaurus. They believe that Sue might have died from a parasitic infection, common today among pigeons, which affects the mouth and throat. So Sue died rather unspectacularly of a sore throat! 

From The Expert

The body proportions and biological habits of T. rex changed dramatically as it grew. The young T. rex was slender, long-limbed, speedy, and had large arms but weak jaws. As the animal aged it became stockier and slower. Its arms wasted away while the jaws became massive and strong. An adult T. rex couldn't chase down prey easily, but it could crunch the bones of anything it met.


Sizing it Up


Compare to:

4m / 13.12ft

T. rex was 1m (3ft) taller than Triceratops.

1 human
1 human
4 m / 13.12 ft


Number of people head-to-toe to reach the top of Tyrannosaurus rex. (average human height 1.76 m / 5.7 ft)

Compare to:

13m / 42.64ft

T. rex was 4m (13ft) longer than Triceratops.

1 human
1 human
13 m / 42.64 ft


Number of people side by side touching finger tips to match this length (average arm span 1.7 m / 5.58 ft ).

Compare to:

7.0tonnes / 7.84short tons

T. rex weighed about the same as Triceratops.

tyrannosaurus rex weight

Number of people weighing 70.31 kg / 155 lbs needed to match the weight of Tyrannosaurus rex.


Dino On The Go!

40kph / 24.85mph

  • Horse 52 kph / 32.3 mph
  • Tyrannosaurus rex40 kph / 24.85 mph
  • Cheetah 120.7 kph / 75 mph

22.5kph / 14mph

The average human sprint speed.


Family Album

Family Album

Tyrannosaurus was a very specialised type of theropod dinosaur, only appearing during the Late Cretaceous period and disappearing along with all dinosaurs (except for birds) during the mass extinction event at the end of the Cretaceous. In fact, Tyrannosaurus would have been one of the last non-avian dinosaurs ever to have walked the Earth.



Tyrannosaurus rex Vision

Tyrannosaurus had the vision of a hawk, pouncing with ease onto its prey.

Tyrannosaurus rex Vision.

Human Vision

The human field of view is roughly 180 degrees.

Human Field of View

The Skinny On Their Skin

Tyrannosaurus rex

There is a possibility that Tyrannosaurus had feathers, because two of its cousins did: the human-sized primitive tyrannosaur Dilong and the much larger, nearly T. rex sized Yutyrannus.


What's In The Nest?

Tyrannosaurus rex Egg

Tyrannosaurus eggs are assumed to fit the usual theropod pattern. They were probably bird-like in shape, measuring between 10 and 15 cm (4-6in) long and a couple of millimetres (0.07in) thick - about the size of a mango. 



tyrannosaurus rex brain size

Tyrannosaurus had a relatively large brain and excellent senses compared to other dinosaurs.


Quite The Bite

Tyrannosaurus' jaw measured 1.5m (5ft) long and had possibly the most powerful bite of any terrestrial animal ever, being equivalent to 3 tonnes in force or the weight of an elephant. 

Tyrannosaurus rex Bite
  • Alligator
  • Lion
  • Leopard
  • Tyrannosaurus rex

    Bite Force (N)


    Average force of human bite, measured at molars.


    Good Eatin'

    Plant Icon

    Tyrannosaurus probably ate the small and medium sized dinosaurs of the time, including Triceratops and young or ailing titanosaurs. There is still debate as to whether T. rex actively hunted or just scavenged. In fact it probably did both.


    Parental Guidance

    Tyrannosaurus rex Parent and Child

    Scientists believe Tyrannosaurus guarded its eggs and watched over its offspring. It was certainly too big to sit on its nest, so T. rex might have used rotting plants to incubate its brood, much like modern alligators today. However, Trex eggs have never been found, so this remains an educated guess. 


    True Colours

    Color Wheel

    If Tyrannosaurus did have feathers, they might have been pretty colourful like a parrot!