Allosaurus was a large carnivorous dinosaur with a length of up to twelve metres (thirty-nine feet), and four metres tall. The animal had a skull that measured three feet long, with a pair of blunt crests just above its eyes, in the orbital region. It had a strong S-shaped neck, and had vertebrae that was different from those of other dinosaurs
Allosaurus also had a large powerful jaw with long, sharp, serrated teeth that were two - four inches long. These teeth were curved inward, shaped like a "D" to help secure its prey. It had a bulky body, a massive tail and thick bones. Its arms were short and had three fingered hands, with sharp claws that were up to six inches long. Allosaurus was one of the largest meat-eating dinosaurs of the Late Jurassic, 156-145 million years ago, and was also one of the largest predators until the tyrannosaurs appeared 50 million years later.
Allosaurus was listed in Connor Temple's database on extinct vertebrates.
When biting down on the remote for Tom and Duncan's TV, Dodi caused the TV to switch over to a scene from the 1925 film The Lost World, in which a Tyrannosaurus rex fought with an Agathaumas and an Allosaurus killing and eating an Anatotitan roaring as it eats.
When the ARC team arrived in a Cretaceous forest, Connor Temple mentioned Allosaurus as one of the creatures possibly living in the forest. However, this was presumably discredited by the fact that the forest was in the Cretaceous rather than Allosaurus' home time in the Jurassic.