Allosaurus

Genus of theropod dinosaur

Allosaurus ( AL-o-SAWR-us) is a genus of theropod dinosaur that lived 155 to 143 million years ago during the late Jurassic period (latest Oxfordian to latest Tithonian ages). 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.

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