[ pey-lee-uh-zoh-ik or, especially British, pal-ee- ]

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

  1. the Paleozoic Era or group of systems.

Origin of Paleozoic

1830–40; paleo- + -zoic<Greek zōïkós pertaining to animals; see zo-, -ic

Other words from Paleozoic

  • post-Pa·le·o·zo·ic, adjective
  • pre-Pa·le·o·zo·ic, adjective

Words Nearby Paleozoic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use Paleozoic in a sentence

Scientific definitions for Paleozoic


[ pā′lē-ə-zōĭk ]

  1. 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.

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