Britannica
Sources used in this answer
What dates mark the Early Jurassic Epoch?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Jurassic Period
Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the late Jurassic Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.
The Early Jurassic Epoch is dated from 201.3 million to 174.1 million years ago.1
This epoch, sometimes referred to as the Lias, represents the first of three subdivisions of the Jurassic Period. The rock system corresponding to this interval is divided into four stages: the Hettangian, Sinemurian, Pliensbachian, and Toarcian.1