Definition of Jurassic in US English:

Jurassic

adjective

Geology
  • 1Relating to or denoting the second period of the Mesozoic era, between the Triassic and Cretaceous periods.

    The Jurassic lasted from about 208 million to 146 million years ago. Large reptiles, including the largest known dinosaurs, were dominant on both land and sea. Ammonites were abundant, and the first birds (including Archaeopteryx) appeared

    • ‘Until recently, sauropod body fossils and ichnofossils were known only from Jurassic and Cretaceous sediments.’
    • ‘These crucial means of breeding prevailed throughout the Jurassic and Cretaceous times.’
    • ‘Striated fault planes exposed in Mesozoic limestones and Triassic / Jurassic volcanic rocks delineate the surface trace of the fault.’
    • ‘The thickness of the Jurassic and Cretaceous cover sediments is relatively thin and the Variscan was the last major erogenic event to have affected the region.’
    • ‘Of the three Triassic and Jurassic fossiliferous formations, no angular fragments were found from the shell beds.’
    1. 1.1as noun the Jurassic The Jurassic period or the system of rocks deposited during it.

Origin

Mid 19th century: from French jurassique; named after the Jura Mountains (see Jura).

Pronunciation

Jurassic

/jəˈrasik//dʒəˈræsɪk/