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

Etymology

Origin of Triassic

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

Example Sentences

See Examples For:

Triassic

In this case, limb bones made it possible to identify a new species, infer aspects of its locomotion, investigate its phylogenetic relationships, and expand the known distribution of a rare group of Triassic reptiles.

From Science Daily ● Aug. 10, 2026

Furthermore, the discovery reinforces Rio Grande do Sul’s status as one of the world’s most important regions for the study of Triassic fauna.

From Science Daily ● Aug. 10, 2026

Eosphorosuchus lacrimosa offers evidence that early crocodile relatives were already developing different feeding adaptations near the beginning of the "Age of Reptiles," during the late Triassic Period, 252 to 201 million years ago.

From Science Daily ● Jul. 30, 2026

During the late Triassic, the ancestors of crocodiles and the lineage that produced dinosaurs were both beginning to expand into new ecological roles.

From Science Daily ● Jul. 30, 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