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Of, relating to, or being the era of geologic time from about 542 to 251 million years ago. The Paleozoic Era includes the Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, and Permian Periods and is characterized by the appearance of marine invertebrates, primitive fishes, land plants, and primitive reptiles. The end of this era is marked by the largest recorded mass extinction in the earth's history, in which 90 percent of marine life forms were wiped out. See Table at geologic time.
The Paleozoic Era.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Pa•le•o•zo•ic(ˌpeɪ li əˈzoʊ ɪk; esp. Brit. ˌpæl i-)
1. noting or pertaining to a geologic era occurring between 570 million and 230 million years ago, when fish, insects, and reptiles first appeared.n.
2. the Paleozoic Era or group of systems.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
The era of geologic time from about 540 to 245 million years ago. The Paleozoic Era is characterized by the appearance of marine invertebrate animals, primitive fish and reptiles, and land plants. See Chart at geologic time.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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|Noun||1.||Paleozoic - from 544 million to about 230 million years ago|
Age of Fishes, Devonian, Devonian period - from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites
Ordovician, Ordovician period - from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds
|Adj.||1.||Paleozoic - of or relating to or denoting the Paleozoic era|
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