Learn how to say Mosasaurus correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word mosasaur:
a large fossil marine reptile of the late Cretaceous period, with large toothed jaws, paddle-like limbs, and a long flattened tail, related to the monitor lizards.
Family Mosasauridae, suborder Lacertilia: several genera, including Mosasaurus
mid 19th century: from modern Latin Mosasaurus, from Latin Mosa, ‘Meuse’ (the river near which it was first discovered) + Greek sauros ‘lizard’