What is the jurassic era.
The Jurassic was the beginning of the age when reptiles dominated the land, sea, and air. During this period, vegetation was greener and more lush. By the late Jurassic, great dinosaurs such as Brachiosaurus, Allosaurus, Ceratosaurus, and Stegosaurus, had evolved on land. Pterosaurs ruled the skies and the earliest known birds appeared.
The Jurassic also saw the breakup of the super-continent Pangea, which began in the Triassic, continue.
The system of rocks deposited during the middle part of the Mesozoic Era, and encompassing an interval of time between about 208 and 145 million years ago, based on radiometric dating. It takes its name from the Jura Mountains, which run along the border of France and Switzerland.
The main continental masses were grouped together as the supercontinent Pangaea, with a northern component, Laurasia, separated from a southern component, Gondwana, by a major seaway, Tethys, which expanded in width eastward (see illustration). From about Middle Jurassic times onward, this supercontinent began to split up, with a narrow ocean being created between eastern North America and northwestern Africa, corresponding to the central sector of the present Atlantic Ocean. At about the same tim ...more