al·​lo·​sau·​rus | \ ˌa-lə-ˈsȯr-əs How to pronounce allosaurus (audio) \

Definition of allosaurus

: any of a genus (Allosaurus) of very large carnivorous North American theropod dinosaurs of the Late Jurassic period

Examples of allosaurus in a Sentence

Recent Examples on the Web Taylor came to see the bones, and identified them as belonging to an allosaurus. Charles Bethea, The New Yorker, "Mark Meadows and the Undisclosed Dinosaur Property," 1 Oct. 2019 Discover fossils at Dinosaur National Monument, Utah Take a giant stride back 150 million years to the Jurassic era and explore the fossils of allosauruses and stegosauruses that once roamed northeastern Utah. National Geographic, "Electrifying places to visit if you love science," 17 June 2019 But people can also bypass that completely and head right toward that violent T. rex vs. triceratops display, as well as to view other dinosaurs like the allosaurus and stegosaurus. David Oliver, USA TODAY, "Want to see a T. rex gnawing on a triceratops? There's a new Smithsonian exhibit for that," 5 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'allosaurus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of allosaurus

1886, in the meaning defined above

History and Etymology for allosaurus

borrowed from New Latin, genus name, from allo- allo- + -saurus -saurus

Note: Genus name introduced by the American paleontologist Othniel Charles Marsh (1831-99) in "Notice of New Dinosaurian Reptiles from the Jurassic Formation," The American Journal of Science and Arts, vol. 114 (3rd series, vol. 14) (Jul.-Dec., 1877), no. 84, pp. 514-16. The combining element allo- is apparently meant to represent its distinctness: "This genus may be distinguished from any known Dinosaurs by the vertebræ, which are peculiarly modified to ensure lightness" (p. 515).

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The first known use of allosaurus was in 1886

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Cite this Entry

“Allosaurus.” Dictionary, Merriam-Webster, Accessed 12 Jul. 2020.

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More Definitions for allosaurus


all·​o·​sau·​rus | \ ˌa-lə-ˈsȯr-əs How to pronounce allosaurus (audio) \

Kids Definition of allosaurus

: a large meat-eating dinosaur related to the tyrannosaur

More from Merriam-Webster on allosaurus

Rhyming Dictionary: Words that rhyme with allosaurus Encyclopedia article about allosaurus

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