|1.||of, denoting, or formed in the first period of the Mesozoic era that lasted for 42 million years and during which reptiles flourished|
|2.||the Triassic, Trias the Triassic period or rock system|
|[C19: from Latin trias triad, with reference to the three subdivisions]|
|Triassic (trī-ās'ĭk) Pronunciation Key
The earliest period of the Mesozoic Era, from about 245 to 208 million years ago. During the early part of the Triassic Period the supercontinent Pangaea was located along the equator; by the end of the Triassic it had started to split up. Land life diversified in the Triassic in response to the mass extinctions of the end of the Paleozoic. Conifers, cycads, marine reptiles, dinosaurs, and the earliest mammals first appeared. See Chart at geologic time.