What does allosaurus mean?
Allosaurus is an extinct genus of predatory theropod dinosaur that lived in North America during the Late Jurassic, roughly 150 million years ago. Its best-known species, Allosaurus fragilis, is particularly associated with the Morrison Formation, where numerous fossils have been found. The animal was a large bipedal hunter with powerful hind legs, sharp recurved teeth, and distinctive bony ridges above the eyes. In general usage, “allosaurus” can refer either to the entire genus or informally to an individual animal belonging to it, while formal scientific writing usually capitalizes the name. The term is also familiar from museum displays, books, films, and popular depictions of prehistoric North America. Its name combines Greek roots meaning “other” or “different” with a root meaning “lizard.” Despite being one of the best-known predatory dinosaurs, Allosaurus remains distinctive through its paired head ridges and its abundance in the fossil record.
nounAllosaurus is an extinct genus of large, carnivorous theropod dinosaur that lived in North America during the Late Jurassic. It is especially known from the species Allosaurus fragilis, one of the most abundant large predatory dinosaurs in the Morrison Formation.
- An extinct large carnivorous theropod dinosaur of the genus Allosaurus, especially Allosaurus fragilis, that lived in North America during the Late Jurassic; the name is also commonly used informally for an individual member of the genus.
"The museum mounted an impressive Allosaurus skeleton at the entrance to its dinosaur gallery."
"Fossil footprints suggest that Allosaurus was an active hunter in the landscapes of the Late Jurassic."
"Children often recognize Allosaurus from its distinctive paired ridges above the eyes and its powerful hind legs."
Allosauruses is the regular English plural, while allosauri is widely used as a plural in paleontology and dinosaur literature.
"Several allosauruses are represented in the museum's collection of Jurassic fossils."
Allosaurus literally means “different lizard”—an unexpectedly modest name for a fearsome Jurassic predator.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does allosaurus come from?
The name Allosaurus was coined by American paleontologist Othniel Charles Marsh in 1877 for a newly described Jurassic dinosaur. It was formed from Greek allos, meaning “other” or “different,” and sauros, meaning “lizard,” thus literally yielding “different lizard.” The suffix sauros also underlies names such as dinosaur, sauropod, and mosasaur, while Heterosaurus follows the same Greek naming pattern.
Related word forms
How allosaurus is actually used
In scientific writing, Allosaurus is treated as a genus name and is conventionally capitalized, although lowercase allosaurus is common when referring informally to the animal or the type of dinosaur. The plural forms allosauruses and allosauri are both accepted.
Easily confused with allosaurus
Allosaurus is the formal genus name, whereas allosaur is a shortened form commonly used for an individual animal of that genus.