A period in the geological time scale that lasted from about 34 to 23 million years ago, characterized by a significant change in climate and the evolution of modern mammals.

ओलिगोसीन युग

English Usage: The Oligocene epoch is known for the diversification of mammals.

Hindi Usage: ओलिगोसीन युग स्तनधारियों के विविधीकरण के लिए जाना जाता है।