Tyrannosaurus rex – from Greek and Latin words meaning ‘tyrant’, ‘lizard’ and ‘king’ – was one of the largest carnivorous dinosaurs to walk the earth. It lived about 85 to 65 million years ago, in lightly forested North American river valleys and plains.
The T-Rex stood more than four metres tall and 12 metres long, weighing in at five to seven metric tons. Some fossil evidence shows that the female T-Rex may have been the larger of the sexes, although there’s no way to know for sure.
Its banana-shaped, serrated teeth gripped flesh and its massive jaw crushed bones as it downed more than 200 kilos of meat in one gulp. Likely prey included the Triceratops horridus and the Torosaurus, each about the size of an elephant.
There have been several nearly complete Tyrannosaurus rex skeletons found since the first bones were discovered in 1894, some of which included soft tissue. From these, palaeontologists have learned that the T-Rex had a lot of bird-like traits. It likely had a one-way air sac system that kept its lungs constantly full of fresh air, hollow bones to lighten its body weight, and binocular, colour sight. It also had a wishbone, or furcula. Some palaeontologists believe that our assumptions of scaly, lizard-like skin might not be entirely accurate and that T-Rex could’ve even had feathers.
Controversy about the T-Rex centres on whether it was a predator or a scavenger, as well as whether it moved slowly or quickly. Many palaeontologists believe that the Tyrannosaurus rex was strictly a predator, but those who question this assumption point to its short, weak arms with two-fingered hands, large legs suited for walking distances and a strongly developed sense of smell. These seem more in line with what we know of scavengers rather than predators. Others argue that muscle scars found on skeletons show that the T-Rex had strong arms. They also believe that their binocular sight and hollow bones indicate a faster-moving predator. However, predators today will sometimes scavenge if fresh prey isn’t around, so T-Rex could’ve actually been both.
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