Jurassic (adj.)

"of or pertaining to the geological period between the Triassic and the Cretaceous," 1823, from French Jurassique, literally "of the Jura Mountains," between France and Switzerland, whose limestones were laid down during this geological period. The name was chosen by von Humboldt. As a noun from 1831. The name is said to be from Gaulish *iuris "wooded mountain."