Allosaurus

Allosaurus (name meaning "different lizard") is a theropod dinosaur that lived in North America during the late Jurassic period.

Description
Allosaurus was a large dinosaur that was on average 8.5 to 9 meters but fragmentary remains indicate it could grow up to 12 metres long, 4 metres high, and weighed 4.5 tonnes (4.6 tons). It had a large metre long skull with crests over its eyes. It had relativley powerful arms with three clawed digits. Recently, some study had been done on the skull of Allosaurus. The results on one Allosaurus fragilis specimen called "Big Al" reveal two extraordinary things about this predator had a weak bite. Allosaurus had relatively weak jaw muscles. It had a bite force of only 200 kilograms, which is the same as a leopard's. It also had fragile teeth. So it was no bone crusher, like tyrannosaurs were. 2. Despite its relatively weak bite, Allosaurus had strong neck muscles and sharp teeth. Its skull was structured to carry tremendous levels of stress. This shows that Allosaurus would have used its head like a hatchet, using its strong neck muscles to ram its jaw into the body of its prey. Dilophosaurus was an ancestor to Allosaurus

Lost World
Allosaurus was briefly seen in a database scene with Carcharodontosaurus.

Fight for Life
An Allosaurus is seen by some Camptosaurus, which bark to alert their herd (composed of both Stegosaurus and Camptosaurus) of danger, but a Stegosaurus walks through their field of vision, blocking their view. When it walks away, the predator has dissapeared. When the Camptosaurus let their gaurd down and resumes eating, the Allosaurus makes its ambush and runs after the Camptosaurus, but they are too fast. The Allosaurus stalks back to the Stegosaurus, first searching for a weak, sick, or young individual. It then approaches a Stegosaurus. It rushes around, dodging its swinging tail and grabs a plate on the stegosaur's back, and then fastens its jaw into its neck. A larger Stegosaurus attacks the Allosaurus, punching a hole in the spine of the Allosaurus. The Allosaurus limps away and crouches on the ground, bleeding and panting with much effort. However, this Allosaurus survived.

Later, another Allosaurus is seen hunting a Camptosaurus. The Camptosaurus looks around, and continues to graze. Another Camptosaurus comes, but suddenly the Allosaurus attacks. It chases one, and rams it's jaw into the Camptosaurus' back repeated, until it collapses and the Allosaurus finishes the prey's life. Just as it takes a bite, a Saurophaganax comes into view. The Saurophaganax bites the Allosaurus on the snout, and steals the kill.

New Giants
Allosaurus was seen in two database scenes explaining how giant killers were always accompanied by giant sauropods, with Diplodocus shown as Allosaurus' accompanying sauropod.

Trivia

 * In the book, Allosaurus' fact file is incorrect. The Allosaurus is shown as the colour of (on the series) Saurophaganax. On the part Hatchet killer the colour is shown as the series shows.
 * It's possible that Saurophaganax is just a large species of Allosaurus, although this is disputed.