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.
- ple·si·o·sau·roid, adjective
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How to use plesiosaur in a sentence
With broad bodies and often lanky necks, plesiosaurs didn’t look like swift swimmers.Analyze This: Bulky plesiosaurs may not have been bad swimmers after all | Carolyn Wilke | September 21, 2022 | Science News For Students
The plesiosaur, on the other hand, had a small and delicate head, with slender teeth and small eyes.The Story of the Earth and Man | J. W. Dawson
In the popular mind, perhaps, the Ichthyosaur and plesiosaur are the typical representatives of that extinct race.The Story of Evolution | Joseph McCabe
He might draw the line at a white plesiosaur riding up to meet his catamaran.Sjambak | John Holbrook Vance
British Dictionary definitions for plesiosaur
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for plesiosaur
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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