Tyrannosaurus rex was a huge, bipedal, carnivorous dinosaur with a large, heavy skull, long tail, and unusually short forearms.
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. Tyrannosaurus has been found as far south as New Mexico and as far north as Canada.
What we heard about their hearing
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
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. Tyrannosaurus jaws were powerful enough to crush bone and extract bone marrow and could open up to 1m (3.28ft) wide.
Nose knowledge
Tyrannosaurus had large olfactory bulbs and nerves, allowing it to sniff out its prey like a great white shark.
The poop scoop
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.
Tyrannosaurus rex features
Height: 4m (13.12ft)
Length: 13m (42.64ft)
Weight: 7 tonnes (7.84 short tons)
Top speed: 40kph (24.85mph)
Vision: Tyrannosaurus had the vision of a hawk, pouncing with ease onto its prey.
Skin: There is a possibility that Tyrannosaurus had feathers, because two of its cousins did: the human-sized primitive tyrannosaur Dilong and the much larger Yutyrannus.
Brain: Tyrannosaurus had a relatively large brain and excellent senses compared to other dinosaurs.
Prey: 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.
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.
Nest: 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 facts and theories
- 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 T. rex wasn't terrifying enough, recent fossil discoveries show that it was also a cannibal. Several T. rex bones have been found with tooth marks perfectly matching the teeth of T. rex. So even a T. rex would have feared T. rex!
- Surprisingly, fossils of T. rex are not very rare. More than half of all dinosaur species are known from only a single fossil, whereas hundreds of specimens of T. rex have been discovered over the past century. This rich fossil record allows scientists to study T. rex in incredible detail.
- 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.
- Scientists have estimated Tyrannosaurus put on the equivalent of the weight of an elephant each year during its teenage growth spurt.