The allosaurus is among the first fossils discovered, but also among those of which the most fossils have been found.
Its name comes from the Greek allos meaning “different” and sauros, meaning “lizard.” At the time of its discovery, it was the only dinosaur to have vertebrae of different shapes.
Due to its large bipedal predator silhouette, it is often confused with Tyrannosaurus rex. But upon closer inspection, you can quickly see that these two dinosaurs are quite different.
The allosaurus had a massive body; its long tail, held horizontally, served as a counterbalance. It was smaller, less massive, and therefore faster than the T-rex, which made it an excellent hunter. Its muscular hind legs allowed it to run at over 30 km/h. Equipped with enormous jaws armed with pointed, serrated teeth like a knife, it could easily tear the flesh of its prey. Moreover, the teeth curved backwards helped prevent prey from escaping its grip. It is considered one of the largest predators of the Jurassic.
Despite having a large skull, it is believed that the allosaurus’s bite force is lower than that of a crocodile or even a lion. To make up for this, it would open its jaw wide, up to 90 degrees, and use the upper part like a club to violently drive its teeth into the body of its prey, tearing its flesh. During its hunts, many teeth would become detached or remain stuck in its victim, but they were quickly replaced throughout its life.