Tertiary

Pronunciation
/TER-she-ary/
Category
Geology
Singular
Tertiary
Plural
Tertiary

Definition

A geologic period lasting from approximately 66 million to 2.5 million years ago, characterized by the diversification and dominance of mammals, birds, and flowering plants.

Etymology

From Latin 'tertius', meaning 'third'.

Example

The Tertiary period saw the rise of many modern mammal groups.

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