[pey-lee-uh-zoh-ik or, esp. British, pal-ee-]Geology


noting or pertaining to an era occurring between 570 million and 230 million years ago, characterized by the advent of fish, insects, and reptiles.


the Paleozoic Era or group of systems.

Origin of Paleozoic

1830–40; paleo- + -zoic < Greek zōïkós pertaining to animals; see zo-, -ic
Related formspost-Pa·le·o·zo·ic, adjectivepre-Pa·le·o·zo·ic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for paleozoic

Historical Examples of paleozoic

  • The period following on after Archean time is called, by geologists, Paleozoic time.

  • It is but a glimpse we get into the immeasurable distance of the Paleozoic.

    The Guardians of the Columbia

    John H. (John Harvey) Williams

  • They existed only during the first half of the Paleozoic era.


    William J. Miller

  • Cambrian , the first period of the Paleozoic era,—that of the first abundance of marine animals.


    Allen Chaffee

  • See what it means to tell these kids about the Paleozoic age and sich, Ruthie!

Word Origin and History for paleozoic



in reference to the geological era between the Precambrian and the Mesozoic, 1838, coined by Adam Sedgwick (1785-1873) from paleo- + Greek zoe "life."

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for paleozoic



The era of geologic time from about 540 to 245 million years ago. The beginning of the Paleozoic Era is characterized by a great diversity of marine invertebrate animals. Primitive fish and reptiles, land plants, and insects also first appeared during this time. The end of the Paleozoic is marked by the largest recorded mass extinction in the Earth's history, which wiped out nearly 90% of known marine life forms. See Chart at geologic time.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.