Definitions for "Jurassic"
Keywords:  mesozoic, triassic, geologic, ago, era
Of the age of the middle Mesozoic, about 190 to 140 million years ago, including, as divided in England and Europe, the Lias, Oölite, and Wealden; -- named from certain rocks of the Jura mountains. It was noted for the predominance of dinosaurs on land, and the development of the first birds and mammals.
The Jurassic period or formation; -- called also the Jura.
208-146 million years ago