Triassic

American  

[trahy-as-ik] / traɪˈæs ɪk /

adjective

1. noting or pertaining to a period of the Mesozoic Era, occurring from 230 to 190 million years ago and characterized by the advent of dinosaurs and coniferous forests.

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noun

1. Also Trias the Triassic Period or System.

Triassic British  

/ traɪˈæsɪk /

adjective

1. of, denoting, or formed in the first period of the Mesozoic era that lasted for 42 million years and during which reptiles flourished

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noun

1. the Triassic period or rock system

Triassic Scientific  

/ trī-ăs′ĭk /

1. 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.

2. See Chart at geologic time

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Other Word Forms

• post-Triassic
  adjective

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Etymology

Origin of Triassic

1835–45; Trias the three-part series of strata characterizing the period (< German < Greek triás; see triad) + -ic

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Example Sentences

See Examples For:

Triassic

"Although British Triassic fossils have been studied for over 200 years, this is the first bone from Saurichthys ever found in these rocks."

From BBC ● Sep. 28, 2026

They discovered it belonged to a Saurichthys - a predator fish that lived in shallow tropical seas during the Late Triassic period.

From BBC ● Sep. 28, 2026

The presence of Silescelida acristata in the Middle Triassic of Brazil shows that the evolutionary history of archosauriforms was broader and more complex than previously thought.

From Science Daily ● Aug. 10, 2026

This suggests that these reptiles were more widely distributed across the world during the Triassic than the fossil record indicated.

From Science Daily ● Aug. 10, 2026

Most of these are also reasonably well known: Cretaceous, Jurassic, Triassic, Silurian, and so on.*

From "A Short History of Nearly Everything" by Bill Bryson

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