The Jurassic Period
At the start of the early Jurassic period, the giant continent Pangaea broke up, forming the beginning of the world that we now know. There were huge volcanoes with rivers of lava and clouds of poison gases.

Land that had been part of the interior of the huge continent was now coastline of smaller continents, and the climate began to change accordingly.

Forests of ferns, ginkgo trees, cycads and conifers grew. All these plants can still be seen today. Scuttling about at the bottom of these plants were the early mammals, all of them rat-sized.

The dominant land animals were the huge dinosaurs, the largest land animals ever. They were the gigantic herbivore (plant-eaters) sauropods such as Diplodocus and Brachiosaurus. Other herbivores included Stegosaursaurus. Carnivorous (meat-eating) dinosaurs included Allosaurus and Dilophosaurus.

The dinosaurs of the Jurassic were much more different from each other than in other periods: there was a greater variety. Because of the different climate, the forests grew, and the herbivores became huge in order to feed on the tall trees. The carnivores then had to become larger and more fierce to deal with such huge prey.

The first birds appeared, such as Archaeopteryx.The seas were full of marine reptiles such as the plesiosaurs, crocodiles, ichthyosaurs, sharks and rays.

 A ginkgo leaf fossil

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updated August 2006