ple·​si·​o·​saur | \ ˈplē-sē-ə-ˌsȯr How to pronounce plesiosaur (audio) , -zē- \

Definition of plesiosaur

: any of an order or suborder (Plesiosauria) of large carnivorous marine reptiles of the Mesozoic with dorsoventrally flattened bodies and limbs modified into flippers

Examples of plesiosaur in a Sentence

Recent Examples on the Web Neither did the squidlike ammonites that curled like rams’ horns, or marine reptiles including the plesiosaurs (Loch Ness conspiracies notwithstanding). Quanta Magazine, "A Rapid End Strikes the Dinosaur Extinction Debate," 25 Mar. 2020 This includes Ichthyosaurs, plesiosaurs, and even the Megalodon – the largest shark known to man. Matthew Cox,, "Guest Mourning Line: How we ended up here and what to do during the coronavirus pandemic," 13 Mar. 2020 While other marine reptiles such as porpoise-like ichthyosaurs and long-necked plesiosaurs had the evolutionary flexibility to expand into deeper ocean environments, hyper-specialized thalattosaurs like Gunakadeit may have struggled to follow suit. Katherine J. Wu, Smithsonian Magazine, "215-Million-Year-Old, Sharp-Nosed Sea Creature Was Among the Last of Its Kind," 5 Mar. 2020 Elasmosaurs make up a family of the plesiosaurs, which represent some of the largest sea creatures of the Cretaceous. National Geographic, "Fossil 'sea monster' found in Antarctica was the heaviest of its kind," 7 June 2019 The legend of the Loch Ness monster has commonly been attributed to a plesiosaur that somehow managed to survive the mass extinction event that killed off the dinosaurs. Fox News, "Loch Ness monster could be a giant eel, researcher claims," 6 Sep. 2019 Some believe Nessie is a long-necked plesiosaur-like an elasmosaur - that somehow survived when all the other dinosaurs were wiped out. Fox News, "Fossil of ‘real-life Loch Ness Monster’ found in Antarctica was the biggest sea dinosaur ever," 11 June 2019 The creature's appearance has been described as resembling a plesiosaur, an ancient sea monster that died out with the dinosaurs. Fox News, "Loch Ness Monster: This is Scotland's plan if the fabled beast is caught," 10 July 2018 Fossil evidence strongly suggests that, like nonavian dinosaurs, plesiosaurs went extinct no later than 66 million years ago. Michael Greshko, National Geographic, "Loch Ness Monster Hunters to Try DNA Search? Get the Facts.," 23 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'plesiosaur.' 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 plesiosaur

1839, in the meaning defined above

History and Etymology for plesiosaur

ultimately from Greek plēsios close (akin to Greek pelas near) + sauros lizard

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The first known use of plesiosaur was in 1839

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Cite this Entry

“Plesiosaur.” Dictionary, Merriam-Webster, Accessed 25 Oct. 2020.

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