Jurassic

The Jurassic (pronunciation: /dʒuːˈræsɪk/; from Jura Mountains) is a geologic period and system that extends from 199.6 Mya (million years ago) to 145.5 Mya; from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period is marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian/Toarcian event in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the "Big Five" mass extinctions.