apato·​sau·​rus | \ ə-ˌpa-tə-ˈsȯr-əs How to pronounce apatosaurus (audio) \
variants: or less commonly apatosaur \ ə-​ˈpa-​tə-​ˌsȯr How to pronounce apatosaurus (audio) \

Definition of apatosaurus

: any of a genus (Apatosaurus of the family Diplodocidae) of very large, herbivorous, sauropod dinosaurs that lived during the Late Jurassic period and reached a length of over 65 feet (20 meters) and a height of 12 feet (3.7 meters) and are thought to have attained a weight of up to 30 tons (27 metric tons)

Note: Apatosauruses were first identified as being of a separate genus (Brontosaurus) and continue to be commonly called brontosauruses or brontosaurs based on this earlier and now invalid classification.

Examples of apatosaurus in a Sentence

Recent Examples on the Web The fossil was found in the same Rocky Mountain region that has produced dinosaurs like apatosaurus, allosaurus and stegosaurus, according to the Utah DNR. Jordan Culver, USA TODAY, 22 May 2020 The resulting film is a sixth-grade sketchbook mash of dino-murder, cartoonish villains, and plot holes big enough for an apatosaurus to fit through. Sam Machkovech, Ars Technica, 22 June 2018 There were stegosauruses, apatosauruses, a T-rex, but the parasaurolophus, in all its weird glory, was always my favorite. Katherine Clover, The Cut, 15 Feb. 2018 Kids can also meet a baby apatosaurus, take an exciting spin in the Jurassic Jeeps and play in themed bounce houses, dig for fossils, do crafts, enjoy face-painting and more. Oc Disney Staff, Orange County Register, 1 Apr. 2017

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

See More

First Known Use of apatosaurus

1878, in the meaning defined above

History and Etymology for apatosaurus

borrowed from New Latin, genus name, from Greek apátē "deceit" (perhaps of substratal origin) + New Latin -o- -o- + -saurus -saurus

Note: The genus name Apatosaurus was introduced by the American paleontologist Othniel Charles Marsh (1831-99) in "Notice of New Dinosaurian Reptiles from the Jurassic formation," American Journal of Science and Arts, 3rd series, vol. 14, no. 74 (December, 1877), pp. 514-16. As with other genera he named, Marsh gives no explanation of the taxon's components. Presumably it was inspired by the distinct chevron bones of Apatosaurus relative to those of other dinosaurs ("The chevron bones differ from those of most known Dinosaurs in having the superior articular ends of the rami not united, but separated from each other, as in the Mososauria with free hæmapophyses.").

Learn More About apatosaurus

Time Traveler for apatosaurus

Time Traveler

The first known use of apatosaurus was in 1878

See more words from the same year

Dictionary Entries Near apatosaurus




See More Nearby Entries 

Statistics for apatosaurus

Cite this Entry

“Apatosaurus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/apatosaurus. Accessed 20 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for apatosaurus


apato·​sau·​rus | \ ə-ˌpa-tə-ˈsȯr-əs How to pronounce apatosaurus (audio) \

Kids Definition of apatosaurus

More from Merriam-Webster on apatosaurus

Britannica.com: Encyclopedia article about apatosaurus


Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!