As the time when the dinosaur first appeared, the Mesozoic era's Triassic period lasted from 245 million years to 208 million years ago. Approximately at this time, all the continents on the earth were clumped together, with the continental areas being dry and rivers and seaside swarmed with ferns, tall coniferous trees, ginkgos and cycads.

Herrerasaurus
Known as one of the oldest kinds of dinosaurs, Herrerasaurus had carnivorous features: a big jaw, sharp teeth, and features favorable for hunting such as long claws and quick and nimble legs. Being about 3~4 m long and weighing 250~300 kg, it was a biped ambulatory animal. It inhabited the northwestern areas of Argentina during the latter part of the Triassic period.

Coelophysis
As a quick and agile dinosaur, its front legs were very short and its body except for the tail was a little bigger than a turkey. In 1947, hundreds of Coelophysis fossils were found in Ghost Ranch, New Mexico. Unlike other large, carnivorous dinosaurs, Coelophysis seemed to have lived in groups, moving in herds. Its body was 3 m at longest and weighed 15~30 kg.

Plateosaurus
As the largest among Triassic-age dinosaurs, it had a small head, long neck, shorter front legs as compared to its well-developed hind legs. It walked on four legs. The big toe had a big claw, which seemed to have been used either for hunting or as a weapon. Its fossils have been found in more than 50 areas in Europe. This herbivorous dinosaur stood 9 m long and weighed 4 tons.