Pa·​leo·​zo·​ic | \ ˌpā-lē-ə-ˈzō-ik How to pronounce Paleozoic (audio) , especially British ˌpa- \

Definition of Paleozoic

: of, relating to, originating in, or being an era of geologic history that extends from the beginning of the Cambrian to the close of the Permian and is marked by the culmination of nearly all classes of invertebrates except the insects and in the later epochs by the appearance of terrestrial plants, amphibians, and reptiles also : relating to the corresponding system of rocks — see Geologic Time Table

Other Words from Paleozoic

Paleozoic noun

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The Greek root zo- means "life," so names such as Paleozoic were invented to refer to a period in the development of animal life. For geologists, the Paleozoic era is followed by the Mesozoic (meso- meaning "middle"), which is followed by the Cenozoic (ceno- meaning "recent"). Eras are huge stretches of time; geologists break eras down into smaller "periods" and "epochs." Thus, the Paleozoic ends with the Permian period, the Mesozoic ends with the Upper Cretaceous epoch, and the Cenozoic ends with the Holocene epoch—the epoch in which we are living. The Paleozoic era produced the first fish, the first land plants, the first insects, and the first amphibians and reptiles; the dinosaurs, birds, and mammals had to wait for the Mesozoic.

First Known Use of Paleozoic

1838, in the meaning defined above

History and Etymology for Paleozoic

paleo- + -zoic entry 2

Note: See note at -zoic entry 2.

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The first known use of Paleozoic was in 1838

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Cite this Entry

“Paleozoic.” Dictionary, Merriam-Webster, Accessed 2 Oct. 2022.

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More Definitions for Paleozoic


Pa·​leo·​zo·​ic | \ ˌpā-lē-ə-ˈzō-ik How to pronounce Paleozoic (audio) \

Kids Definition of Paleozoic

: an era of geological history ending about 280 million years ago which came before the Mesozoic and in which vertebrates and land plants first appeared

More from Merriam-Webster on Paleozoic

Nglish: Translation of Paleozoic for Spanish Speakers


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