Theropoda › Allosaurus
Allosaurus
Allosaurus fragilis
- Length 9 m
- Mass 2700 kg
Allosaurus is a genus of theropod dinosaur that lived 155 to 143 million years ago during the late Jurassic period. The first fossil remains that could definitively be ascribed to this genus were described in 1877 by Othniel C. Marsh. The name "Allosaurus" means "different lizard", alluding to its lightweight vertebrae, which Marsh believed were unique. The genus has a very complicated taxonomy and includes at least three valid species, the best known of which is A. fragilis. The bulk of Allosaurus remains come from North America's Morrison Formation, with material also known from the Alcobaça, Bombarral, and Lourinhã formations in Portugal. It was known for over half of the 20th century as Antrodemus, but a study of the abundant remains from the Cleveland-Lloyd Dinosaur Quarry returned the name "Allosaurus" to prominence. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles.
Attributes
- Length
- 9 m
- Mass
- 2700 kg
- Time range
- 154.8 - 143.1 Ma
- Size class
- Medium
- Region
- United States
Sources
Facts are drawn from the Paleobiology Database and Wikipedia. Images are reconstructions, not photographs.
