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Any of various extinct carnivorous marine reptiles of the family Mosasauridae of the Cretaceous Period, having an elongated body, powerful jaws, and paddlelike limbs. Some species reached lengths of over 15 meters (50 feet).

[New Latin Mosasaurus, genus name : Latin Mosa, the Meuse River (where fossils of the genus were first discovered) + Greek sauros, lizard.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˈməʊsəˌsɔː) or


n, pl -saurs or -sauri (-ˈsɔːraɪ)
(Palaeontology) any of various extinct Cretaceous giant marine lizards of the genus Mosasaurus and related genera, typically having paddle-like limbs
[C18: from Latin Mosa the river Meuse (near which remains were first found) + -saur]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈmoʊ səˌsɔr)

any of several extinct carnivorous marine lizards from the Cretaceous Period, having the limbs modified into broad, webbed paddles.
[< New Latin Mosasaurus (1823) genus name = Latin Mosa the Muse river (where first discovered) + New Latin -saurus -saur]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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References in periodicals archive ?
The 4ft-long skull of the mosasaur was unearthed on Seymour Island, off the Antarctic peninsular, in 2010.
Some suggest he was describing a mosasaur, a 60ft marine reptile featured in the movie Jurassic World.
At the top of this prehistoric food chain, stretching up to nearly 15 metres (50 feet) and weighing a hefty 50,000 kilograms (50 tonnes), ruled the mighty mosasaur, the T-Rex of the sea.
The Mosasaur is said to be freakishly big, with some fans wondering how they were able clone the underwater creature with no mosquitoes going under water.
Toronto, Canada, September 17, 2014 --( A monstrous 4.5-foot Mosasaur skull from Morocco highlights the many prehistoric and geological treasures found at Fossil Realm's September show on Sept.
The unique soft tissue remains were obtained from a 55 million-year-old leatherback turtle, an 85 million-year-old mosasaur and a 196 million-year-old ichthyosaur.
The geographic area where Prognathodon, a member of the mosasaur family, was discovered was originally under water, and the creature is actually a giant marine reptile, he said.
Upstairs in the entrance lobby Alan Dietrich and Fred Nuss displayed one of their important finds from the chalk beds of Kansas, a 22-foot-long skeleton of an 85-million-year-old sea creature, Mosasaur tylosaurus.