Allosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period. The name Allosaurus means "different lizard". It is derived from the Greek ἅλλος/allos ("different, other") and σαυρος/sauros ("lizard"). The first remains that can definitely be ascribed to this genus were described in 1877 by paleontologist Othniel Charles Marsh. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles. Indeed, it has been a top feature in several films and documentaries about prehistoric life...