Jurassic Period

Triassic Period - Jurassic Period - Cretaceous Period

The Jurassic Period is the second period of the Mesozoic Era, and the eighth of the Phanerozoic Eon. This period begins with the Triassic-Jurassic extinction event and tentatively ends with the base of the M18r chron.

The supercontinent on Pangaea broke up at the beginning of the period, and two distinct continents - Gondwana and Laurasia - formed from its remains. The Atlantic Ocean and the Gulf of Mexico both began to form during the period.

The dominant plant species of the period were the conifers and the gymnosperms. The skies were dominated by pterosaurs throughout the period, while the dominant terrestrial animals were the dinosaurs. The seas were dominated by many groups of marine reptiles, including the ichthyosaurs and plesiosaurs. Most major groups of dinosaurs had evolved by this period, including the ankylosaurs, the ceratopsians, the ornithopods, the prosauropods, the sauropods, the stegosaurs, and the theropods. Included in the theropod group that evolved in the Jurassic are the first birds.

The Jurassic is subdivided into three epochs: the Early Jurassic, the Middle Jurassic, and the Late Jurassic.

Jurassic Timescale:

Jurassic Period - 201.36-145 MYA

-Early Jurassic Epoch - 201.36-174.1 MYA

--Hettangian Age - 201.36-199.4 MYA

--Sinemurian Age - 199.4-191.36 MYA

--Pliensbachian Age - 192.36-183.7 MYA

--Toarcian Age - 183.7-174.1 MYA

-Middle Jurassic Epoch - 174.1-163.1 MYA

--Aalenian Age - 174.1-170.3 MYA

--Bajocian Age - 170.3-168.3 MYA

--Bathonian Age - 168.3-166.1 MYA

--Callovian Age - 166.1-163.1 MYA

-Late Jurassic Epoch - 163.1-145 MYA

--Oxfordian Age - 163.1-157.3 MYA

--Kimmeridgian Age - 157.3-152.1 MYA

--Tithonian Age - 152.1-145 MYA