Allosaurus means “different lizard.” and was named by Othniel Charles Marsh. Allosaurus was one of the most prevailing carnivorous dinosaurs throughout the Late Jurassic 145 – 155 million years ago. Among the best-known theropods, paleontologists have discovered numerous remains around the globe. Allosaurus dominated Western North America during the Late Jurassic period and was on the top of the hierarchy. The Allosaurus diet was mostly large herbivores.

What Does Allosaurus Mean

The name Allosaurus did derive from the Greek allos (“different” or “other”) and sauros (“lizard”). During the discovery, in 1877. At the time, it was quite different than other dinosaurs known, therefore named “different lizard.” although that is not true at the current time.

What Does A Allosaurus Look Like

What did allosaurus look like

Allosaurus had a short neck and quite a large skull. The skull contained a distinctive pair of horns located over the eyes. Compared to the hindlimbs, Allosaurus had shorthand’s with sharp, large claws.

Juvenile Allosaurus had comparatively more elongated legs as opposed to adults. Paleontologists possibly suggest Juvenile Allosaurus required more speed to hunt prey in small sizes compared to adults. Adult Allosaurus was more of an ambush predator.

Where and When Did The Allosaurus Live

Allosaurus got discovered in the Morrison Formation, lived mostly in Western North America. The Morrison Formation is a semiarid environment with distinct wet and dry seasons and flat floodplains[1]. Floodplains are the ideal environment for an ambush predator Allosaurus, hunting near riversides where large herbivores drank water to ambush.

Allosaurus lived in the Late Jurassic period, 145 – 155 million years ago.

What Did Allosaurus Eat

Allosaurus was large-carnivorous dinosaurs. Most of their diet consisted of large sauropods. Paleontologists found scraping on sauropod bones suiting Allosaurus teeth shows that they were scavengers as well as active hunters.


Sauropods were the largest herbivores in the history of the earth have seen sizes ranging around 15-20 meters in length and weight of 15 tons.

  • Brachiosaurus
  • Camarasaurus
  • Haplocanthosaurus
  • Cathetosaurus
  • Suuwassea
  • Apatosaurus
  • Brontosaurus
  • Barosaurus
  • Diplodocus
  • Supersaurus
  • Amphicoelias

Did Allosaurus Have Feathers

Paleontologists are not sure if Allosaurus had feathers or not. Phylogenic bracket states it’s likely but nothing absolute. It’s more probable that any given theropod would be at least partially feathered than unfeathered. Paleontologist agrees on Tyrannosaurus rex having feathers, although Tyrannosaurus only was covered in feathers when they were juveniles as they grow, became more scaly, this could be the situation for Allosaurus as well though they not in the same family. There are confirmed indications of dinosaurs being covered in feathers such as Velociraptor, Utahraptor and Deinonychus.

Did Allosaurus Hunted In Packs

Social behavior among Allosaurus has speculated since the 1970s. Allosaurus is believed to show social behavior such as hunting in pack and grouping. Rather than docile cooperative interactions, it was more of aggressive interactions that took place between the groups, could have been due to fighting for the alpha status or leader of the group could have been the case. Allosaurus also shows signs of cannibalism. A study of paleontologists suggests that Allosaurus’ social behavior is quite similar to crocodiles and komodo dragons.

A paleontologist believed the found shed of allosaur teeth and chewed bones of large prey were an indication of parental care of Allosaurs, meat pieces were carried to their juvenile.

How Fast Can Allosaurus Run

The legs of Allosaurus were not suited for speed. Allosaurus was an ambush predator it didn`t prefer long chases. The speed of Allosaurus running(top speed) speed been estimated to be around 19 – 34 mph (30 – 55 kph) [2]

Allosaurus Size (Height and Weight)

Allosaurus weight has been controversial since 1976 as the latest studies have shown Allosaurus weighed 3,100 lb – 4,400 lb (1,400 kg – 2,000 kg). The biggest found Allosaurus reached 32 ft (9.7m) in length while on average, they were 28ft (8.5 m).


  1. Russell, Dale A. (1989). An Odyssey in Time: Dinosaurs of North America. Minocqua, Wisconsin: NorthWord Press. pp. 64–70. ISBN 978-1-55971-038-1.
  2. Christiansen, Per (1998). “Strength indicator values of theropod long bones, with comments on limb proportions and cursorial potential”. Gaia15: 241–255. ISSN 0871-5424