- Latinized variant of -saur: brontosaurus.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Word Origin and History for -saurus
element used in forming dinosaur names, from Latinized comb. form of Greek sauros "lizard," of unknown origin; possibly related to saulos "twisting, wavering."
Online Etymology Dictionary, © 2010 Douglas Harper