plesiosaur

American  

[plee-see-uh-sawr] / ˈpli si əˌsɔr /

noun

1. any marine reptile of the extinct genus Plesiosaurus, from the Jurassic and Cretaceous periods, having a small head, a long neck, four paddlelike limbs, and a short tail.

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plesiosaur British  

/ ˈpliːsɪəˌsɔː /

noun

1. any of various extinct marine reptiles of the order Sauropterygia, esp any of the suborder Plesiosauria, of Jurassic and Cretaceous times, having a long neck, short tail, and paddle-like limbs See also ichthyosaur Compare dinosaur pterosaur

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plesiosaur Scientific  

/ plē′sē-ə-sôr′ /

1. Any of various large, extinct marine reptiles of the genus Plesiosaurus and related genera of the Mesozoic Era. Most plesiosaurs had a small head on a long neck and a broad body with paddlelike limbs; one group had a large head on a short neck. The exact relationship between plesiosaurs and other reptiles is not known.

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Other Word Forms

• plesiosauroid
  adjective

Etymology

Origin of plesiosaur

< New Latin Plesiosaurus (1821), equivalent to Greek plēsí ( os ) near, close to + -o- -o- + saûros -saur; originally so named because of its conjectured nearness to modern reptiles, relative to the ichthyosaurs

Example Sentences

See Examples For:

plesiosaur

His first thoughts were that it might be another marine reptile like an ichthyosaur or plesiosaur.

From BBC ● Apr. 22, 2026

Pliosaurs were a type of plesiosaur with short necks and massive skulls.

From Science Daily ● Oct. 20, 2023

Numerous theories or explanations have been put forward over the years, including that the creature may have been a plesiosaur, a prehistoric marine reptile, giant eels or even swimming circus elephants.

From Seattle Times ● Aug. 5, 2023

No evidence of a prehistoric marine reptile called a plesiosaur or a large fish such as a sturgeon were found.

From BBC ● May 12, 2023

Two plesiosaur artillery units had peeled off after her; she could see the glow of their lanterns shivering in the ocean breeze and hear their riders yelling back and forth.

From "Dactyl Hill Squad" by Daniel José Older