Tertiary period

n. geological period of 63 million to 2 million years ago that is part of the Cenozoic era

For other meanings of the word "tertiary", see . The Tertiary geological time interval covers roughly the time span between the demise of the non-avian dinosaurs and beginning of the most recent Ice Age, approximately 65 million to 1.8 million years ago.At the beginning of the period mammals replaced reptiles as the dominant vertebrates. Each epoch of the Tertiary was marked by striking developments in mammalian life. The earliest recognizable hominoid relatives of humans, Proconsul and Australopithecus, appeared. Modern types of birds, reptiles, amphibians, fish, and invertebrates were either already numerous at the beginning of the period or appeared early in its history. Modern families of flowering plants evolved. Marine invertebrates and non-mammal marine vertebrates experienced only modest evolution.
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Noun
1. from 63 million to 2 million years ago
(synonym) Tertiary
(hypernym) period, geological period
(part-holonym) Cenozoic, Cenozoic era, Age of Mammals
(part-meronym) Pliocene, Pliocene epoch

65-2 Million Years Ago
Part of the Cenozoic era, the Tertiary period is divided into five epochs: Paleocene, Eocene, Oligocene, Miocene, and Pliocene. During this time mammals diversify quickly. Some examples are marsupials, insectivores, bears, hyenas, dogs, cats, seals, walruses, whales, dolphins, early mastodonts, hoofed mammals, horses, rhinoceroses, hippopotamuses, oreodonts, rodents, rabbits, monkeys, lemurs, apes, and humans (Australopithecus).
Indricotherium 
Brontotherium 
see list of time periods