Word.ws English Dictionary

plesiosaur

/ˈpliːsiəsɔːɹ/

plesiosaur noun: any of the order †Plesiosauria of extinct marine reptiles, from the Jurassic and Cretaceous periods.

plesiosaur: any of the order †Plesiosauria of extinct marine reptiles, from the Jurassic and Cretaceous periods
Image: Dmitry Bogdanov, CC BY 3.0, via Wikimedia Commons

Noun

plesiosaur (plural plesiosaurs)

  1. Any of the order †Plesiosauria of extinct marine reptiles, from the Jurassic and Cretaceous periods.
    • "Look!" cried Olson. "Would you look at the giraffe comin' up out o' the bottom of the say?" We looked in the direction he pointed and saw a long, glossy neck surmounted by a small head rising above the surface of the river. Presently the back of the creature was exposed, brown and glossy as the...1918 September–November, Edgar Rice Burroughs, “The Land That Time Forgot”, in The Blue Book Magazine, Chicago, Ill.: Story-press Corp., →OCLC; republished as chapter IV, in Hugo Gernsback, editor...
    • It is the first time in Australia the head and body of an elasmosaur, a type of plesiosaur, has been found in one piece.2022 December 6, Rachael Merritt, “Australia's first complete plesiosaur fossil discovered in outback Queensland”, in ABC News

Forms of plesiosaur

pluralplesiosaurs

Origin of plesiosaur

Backformation of translingual Plesiosaurus, named by William Conybeare and Henry De la Beche in 1824 because plesiosaurs were more like a normal reptile than Ichthyosaurus, which had been found in the same rock strata a few years earlier. Surface derivation, plesio- + -saur.

Questions about plesiosaur

What does plesiosaur mean?
Plesiosaur means any of the order †Plesiosauria of extinct marine reptiles, from the Jurassic and Cretaceous periods.
What part of speech is plesiosaur?
Plesiosaur is a noun.
How do you pronounce plesiosaur?
Plesiosaur is pronounced /ˈpliːsiəsɔːɹ/.
What is the plural of plesiosaur?
The plural of plesiosaur is plesiosaurs.

Words near plesiosaur in the dictionary

  1. plesiopelvic
  2. plesiopid
  3. plesiopids
  4. plesiopithecid
  5. plesiopithecids
  6. plesiosaur
  7. plesiosaurian
  8. plesiosaurians
  9. plesiosaurid
  10. plesiosaurids
  11. plesiosaurlike

Source and license

Adapted from Wiktionary: plesiosaur (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Vealhurl-plesiosaur.wav.

Cite this entry: “plesiosaur.” Word.ws, https://word.ws/plesiosaur. Based on Wiktionary, CC BY-SA 4.0.