Earth Geology Geologic Time Scale Jurassic Period

Jurassic Period

The Jurassic time period lasted from 208 to 146 million years ago, a time span of 62 million years. The term Jurassic was first used in the 1830s to describe a sequence of rocks in the Jura Mountains in Switzerland. These Jurassic rocks were defined based on a particular type of fossil assemblage contained within them. They are located above the rocks of the Triassic System and below the rocks of the Cretaceous System.