Allosaurus was a carnivore from the late Jurassic Period. It was about 8.5 metres long and weighed 3,600kg.

How did Allosaurus get its name?

"Allosaurus" comes from two Greek words:

  • Allo meaning "different," and
  • Saurus meaning "lizard"

So if you put the words together, the name means "different lizard."


Allosaurus's backbone was different than other dinosaurs. Instead of being mostly solid bone, the vertebre was filled with air sacs, making it lighter than those of other dinosaurs.

Allosaurus had bony ridges over its eyes.

What else is really cool about Allosaurus?

  • The most famous Allosaurus skeleton is called "Big Al."
  • Allosaurus was the official state fossil of Utah.
  • Allosaurs had hooked teeth and claws for hanging onto struggling prey.

Created by Carrie Johns
Copyright April 28, 2018
Revised April 29, 2018