geological period
English Thesaurus
1. a unit of geological time during which a system of rocks formed (noun.time)
| hypernym | : | geologic time, geological time, |
| definition | : | the time of the physical formation and development of the earth (especially prior to human history) (noun.time) |
| instance hyponym | : | cretaceous, cretaceous period, |
| definition | : | from 135 million to 63 million years ago; end of the age of reptiles; appearance of modern insects and flowering plants (noun.time) |
| instance hyponym | : | jurassic, jurassic period, |
| definition | : | from 190 million to 135 million years ago; dinosaurs; conifers (noun.time) |
| instance hyponym | : | triassic, triassic period, |
| definition | : | from 230 million to 190 million years ago; dinosaurs, marine reptiles; volcanic activity (noun.time) |
| instance hyponym | : | permian, permian period, |
| definition | : | from 280 million to 230 million years ago; reptiles (noun.time) |
| instance hyponym | : | age of fishes, devonian, devonian period, |
| definition | : | from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites (noun.time) |
| instance hyponym | : | silurian, silurian period, |
| definition | : | from 425 million to 405 million years ago; first air-breathing animals (noun.time) |
| instance hyponym | : | ordovician, ordovician period, |
| definition | : | from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds (noun.time) |
| instance hyponym | : | cambrian, cambrian period, |
| definition | : | from 544 million to about 500 million years ago; marine invertebrates (noun.time) |
| part holonym | : | epoch, |
| definition | : | a unit of geological time that is a subdivision of a period and is itself divided into ages (noun.time) |
| part meronym | : | era, geological era, |
| definition | : | a major division of geological time; an era is usually divided into two or more periods (noun.time) |
Visual ArtiKata
Explore geological period in ArtiKata.com >