The massively popular 1990 novel Jurassic Park by Michael Crichton and its subsequent movie adaptations led to a huge resurgence in interest in dinosaurs and the prehistoric world. That interest continues to the present day, even though most of the dinosaurs in Jurassic Park weren't actually from the Jurassic period. Triceratops, Velociraptor, Tyrannosaurus Rex and the huge sauropods such as Brachiosaurus that feature in the book and movies all actually belong to the Late Cretaceous period, more than 40 million years after the end of the Jurassic. Regardless, certain kinds of dinosaurs remain instantly recognizable, and among them, the "king" is undoubtedly the Tyrannosaurus.

The first discovery of a Tyrannosaurus was made in 1902 and the largest carnivorous dinosaur ever found at the time quickly gripped the popular imagination. Even its name was dramatic - Tyrannosaurus Rex means "King of the Tyrant Lizards." The T-Rex as it quickly became known didn't appear until the last age of the Late Cretaceous period, the Maastrichtian, but when it did, it was the biggest and most terrifying of all the theropod predators. The T-Rex was around 13 feet tall at the hips (its tallest point since it isn't believe to have stood upright), it was over 35 feet long, and it weighed about nine metric tons. Like most therapods, it had very powerful hind legs and much smaller fore legs, so the front legs look almost comically small. This dinosaur also had a large and powerful tail to counterbalance its very large head (some T-Rex skulls are nearly five feet long). Within the skull was a massive jaw lined with teeth up to a foot long. A reconstructive study has estimated that a T-Rex jaw was capable of exerting a pressure of over 55,000 Newtons; the equivalent of almost six tons of pressure. It was fast too, possibly capable of moving at speeds of up to 25 miles per hour.