About
Few animals in the history of life have captured human imagination like Tyrannosaurus rex. With a skull over 1.5 meters long packed with banana-sized teeth, T-Rex was the of its world — and it knew it.
For decades, scientists debated whether T-Rex was an active hunter or a . The answer, it turns out, is both. Bite marks found on Triceratops bones show healed injuries — meaning the prey survived the attack — settling the question: T-Rex hunted live prey.
Its famous tiny arms weren't or useless. Recent research suggests they may have been used to grip struggling prey at close range, or during mating. Each arm could curl roughly 180 kilograms.
T-Rex almost certainly had some form of feathering, at least during early life stages — close relatives like Yutyrannus were fully feathered. Whether adults retained feathers or had scaly skin (like the impressions found with some specimens) is still debated.
The largest known individual, nicknamed 'Scotty,' lived in what is now Saskatchewan and is estimated to have weighed over 8,800 kg — making it the heaviest land predator on record.
Explore the anatomy
5 featuresOver 1.5 metres long, this massive skull had large holes throughout that kept it light but strong — essential for handling a bite force of up to 57,000 newtons (enough to crush a car). Fossil skulls like the famous 'Sue' show textured surfaces on the snout, hinting that it may have been covered in tough, horn-like skin rather than bare bone.
Instead of thin, blade-like teeth for slicing, these chunky teeth were D-shaped and built for crushing — powerful enough to splinter bone and get to the nutritious marrow inside. Bite marks matching these teeth have been found on Triceratops and Edmontosaurus bones, and some prey fossils even show healed wounds, proving this was a hunter, not just a scavenger.
Those famously small arms were actually surprisingly powerful, with two strong clawed fingers that could have gripped prey up close. A 2022 study suggested they may have shrunk on purpose over time — shorter arms meant less chance of getting them accidentally bitten off during group feeding!
Fossilised skin impressions show patches of small, pebbly scales on areas like the neck and tail. But here's the twist: a feathered relative called Yutyrannus weighed over a tonne and was covered in fluff, so young T-Rex or those living in colder climates might have had feathers too. Scientists are still debating this one!
Forward-facing eyes gave a binocular vision field of about 55 degrees — better than a hawk's — meaning excellent depth perception for judging exactly when to strike. Brain casts also reveal huge smell-processing areas, so this predator hunted with both super sharp eyesight and an incredible sense of smell.
Where fossils were found
Hell Creek Formation
+1 more formation
Montana, North Dakota, South Dakota, Wyoming · United States
72.2–66 million years ago(6.2m year span)
Where T-Rex Roamed
Keep exploring the vault
Triceratops
Triceratops horridus
Multiple Triceratops fossils from Hell Creek and Lance formations show T. rex bite marks on frill and horn cores.
Edmontosaurus
Edmontosaurus regalis
Edmontosaurus tail vertebrae from the Hell Creek Formation show healed T. rex bite marks, demonstrating predation on living animals.
Giganotosaurus
Giganotosaurus carolinii
Both represent independent evolution of giant apex theropod predators — Giganotosaurus from Carcharodontosauridae in South America (Cenomanian, ~97 mya) and T. rex from Tyrannosauridae in North America (Maastrichtian, ~68 mya).
Nanuqsaurus
Nanuqsaurus hoglundi
Same family: Tyrannosauridae
Gorgosaurus
Gorgosaurus libratus
Same family: Tyrannosauridae
Carcharodontosaurus
Carcharodontosaurus saharicus
Parallel evolution of giant theropod apex predators on different continents — Carcharodontosaurus in Africa and T. rex in North America.