from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Of or belonging to the geologic time, rock series, or sedimentary deposits of the second period of the Mesozoic Era, in which dinosaurs continued to be the dominant land fauna and the earliest birds appeared. See Table at geologic time.
  • n. The Jurassic Period or its system of deposits.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Of or pertaining to the second period of the Mesozoic era, a time still dominated by dinosaurs.
  • adj. Of or pertaining to the people or region near the Jura Mountain Range of Europe.
  • proper n. The period from 200 to 146 million years ago, after the Triassic and before the Cretaceous; the geologic formations of this period.

from the GNU version of the Collaborative International Dictionary of English

  • adj. 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.

from The Century Dictionary and Cyclopedia

  • Pertaining or relating to the Jura mountains, and specifically, in geology, to the Jurassic series.
  • n. In geology, that part of the geological series which includes all the groups and subgroups older than the Cretaceous and newer than the Triassic: so called from the predominance of rocks of this age in the Jura mountains.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. of or relating to or denoting the second period of the Mesozoic era
  • n. from 190 million to 135 million years ago; dinosaurs; conifers


French jurassique, after the Jura (Mountains) .
(American Heritage® Dictionary of the English Language, Fourth Edition)
Named for the discovery and type location in the Jura Mountains of Switzerland. (Wiktionary)



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