[ mez-uh-zoh-ik, mes-, mee-zuh-, -suh- ]

  1. noting or pertaining to an era occurring between 230 and 65 million years ago, characterized by the appearance of flowering plants and by the appearance and extinction of dinosaurs.

  1. the Mesozoic Era or group of systems.

Origin of Mesozoic

First recorded in 1830–40; meso- + zo- + -ic

Other words from Mesozoic

  • post-Mes·o·zo·ic, adjective

Words Nearby Mesozoic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use Mesozoic in a sentence

  • The evidence furnished by Palozoic and Mesozoic formations points chiefly to mild, genial, and sometimes tropical conditions.

    Geology | James Geikie
  • The next or closing period of this great Mesozoic time brought a wondrous change.

British Dictionary definitions for Mesozoic


/ (ˌmɛsəʊˈzəʊɪk) /

  1. of, denoting, or relating to an era of geological time that began 250 000 000 years ago with the Triassic period and lasted about 185 000 000 years until the end of the Cretaceous period

  1. the Mesozoic the Mesozoic era

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for Mesozoic


[ mĕz′ə-zōĭk ]

  1. The era of geologic time from about 245 to 65 million years ago. The Mesozoic Era was characterized by a drastic change in plants and animals. In the early part of the Mesozoic, ferns, cycads, and ginkgos were dominant; later, gymnosperms and angiosperms developed. Dinosaurs also first appeared in the Mesozoic and, with the exception of birds, became extinct at the end of the era. See Chart at geologic time.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.