The Jurassic period (199.6 million to 145.5 million years ago) was characterized by a warm, wet climate that gave rise to lush vegetation and abundant life. Many new dinosaurs emerged—in great numbers. Among them were stegosaurs, brachiosaurs, allosaurs, and many others.
During this period, Earth's climate changed from hot and dry to humid and subtropical.
Dinosaurs, birds, and rodents. Crumbling landmasses and inland seas. Sea monsters, sharks, and blood-red plankton. Forests of ferns, cycads, and conifers. Warm, moist, tropical breezes. This was the Jurassic, which took place 199 to 145 million years ago.
At the start of the period, the breakup of the supercontinent Pangaea continued and accelerated. Laurasia, the northern half, broke up into North America and Eurasia. Gondwana, the southern half, began to break up by the mid-Jurassic. The eastern portion—Antarctica, Madagascar, India, and Australia—split from the western half, Africa and South America. New oceans flooded the spaces in between. Mountains rose on the seafloor, pushing sea levels higher and onto the continents.
All this water gave the previously hot and dry climate