Tertiary

Tertiary, or CAINOZOIC, the term applied in the science of Geology (q.v.) to all the strata of the earth's crust above the Cretaceous Rocks, with the exception of those superficial beds which have recently been raised to a distinct group, under the title of the Quaternary or Post-tertiary. The Tertiary systems include Eocene, Oligocene, Miocene, and Pliocene.