Geological history of Earth living in lagoons and hypersaline environments, such as "Estheria" crustaceans and terrestrial vertebrates. The Jurassic Period extends from about 201.3 ± 0.2 to 145.0 Ma. During the early Jurassic, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan Peninsula. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous Period, when Gondwana itself rifted apart. The Tethys Sea closed, and the Neotethys basin appeared. Climates were warm,
Pangean megamonsoon solar insolation shifted toward the Southern Hemisphere. Air then traveled from Laurasia (region of high pressure), across the Tethys Ocean to Gondwana (region of low pressure). Moisture advection toward the Southern Hemisphere would have fueled heavy precipitation along the Gondwana coasts, while Laurasia remained very dry. There are marked similarities between factors contributing to the East Asian monsoon and those that would have influenced Pangean climate. This not only supports the theory that Pangean climate was dominated by the monsoon, but also aids in the study of it, providing paleoclimatologists with a present-day example to which they can compare their