Climate and Geography In Triassic times, all of the earth's continents were joined together into a vast landmass called Pangaea (which was itself surrounded by an enormous ocean called Panthalassa). There were as yet no polar ice caps, and the climate was hot and dry, punctuated by violent monsoons.
Terrestrial Life The start of the Triassic followed the Permian Extinction, an event of unknown cause that wiped out over two-thirds of land-dwelling vertebrates. Taking their place were strangely mammalian-looking reptiles called cynodonts, early dinosaurs like Herrerasaurus and Eoraptor, and primitive reptiles called archosaurs, from which some dinosaurs (as well as all crocodiles) later evolved.
Aquatic Life Because the Permian Extinction wiped out about 95 percent of all ocean-dwelling animals, the Triassic was ripe for the rise of aquatic reptiles, such as Placodus and Nothosaurus. The vast Panthalassan Ocean was soon restocked with new species of fish, as well as simple animals like corals and cephalopods.
Avian Life Except for insects, the skies of the early Triassic were relatively quiet. It was only toward the end of this period that the earliest pterosaurs, such as Eudimorphodon, appeared, and they probably weren't the most accomplished flyers.
Plant Life The Triassic wasn't nearly as lush and green as the later Jurassic and Cretaceous periods, but it did see an explosion of various land-dwelling plants, including cycads, ferns, and Gingko-like trees. Part of the reason there were no enormous dinosaurs in the Triassic (along the lines of Brachiosaurus) is that there simply wasn’t enough vegetation to nourish them!
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