designating or of the first geologic period of the Mesozoic Era, characterized by the breakup of Pangea, the development of tall forests of cycads and conifers, and the presence of the first dinosaurs, turtles, frogs, and small mammals
Origin of Triassic; from German triassisch (; from Late Latin Trias (see triad: because divisible into three groups) + -isch, -ic
the Triassic Period or its rocks
also the Tri′as
Of, relating to, or being the period of geologic time from about 251 to 199 million years ago, the oldest period of the Mesozoic Era. The Triassic Period is characterized by the presence of the supercontinent Pangaea, the diversification of land life, the rise of dinosaurs, and the appearance of the earliest mammals. See Table at geologic time.
The Triassic Period.
Origin of TriassicLate Latin trias, triad (from the subdivision of this period into three parts); see triad + –ic.