Precambrian

American  

[pree-kam-bree-uhn, -keym-] / priˈkæm bri ən, -ˈkeɪm- /

Or Pre-Cambrian

adjective

1. noting or pertaining to the earliest era of earth history, ending 570 million years ago, during which the earth's crust formed and life first appeared in the seas.

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noun

1. the Precambrian Era.

Precambrian British  

/ priːˈkæmbrɪən /

adjective

1. of, denoting, or formed in the earliest geological era, which lasted for about 4 000 000 000 years before the Cambrian period

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noun

1. the Precambrian era See Archaeozoic Proterozoic

Precambrian Scientific  

/ prē-kăm′brē-ən,-kām′- /

1. The period of geologic time between Hadean Time and the Phanerozoic Eon, from about 3.8 billion to 540 million years ago. During the Precambrian Eon, which is divided into the Archean and Proterozoic, primitive forms of life first appeared on Earth.

2. See Chart at geologic time

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Etymology

Origin of Precambrian

First recorded in 1860–65; pre- + Cambrian

Example Sentences

But it wasn't till the Precambrian extinction 544 million years ago that they burst through their previous limits, generating new species that found new ways to live.

From Salon • Feb. 25, 2025

But a UC Riverside-led team has now identified the oldest known ecdysozoan in the fossil record and the only one from the Precambrian period.

From Science Daily • Nov. 18, 2024

They argued the cuts would cripple studies of museum collections holding some 5 million items, including a renowned trove of Precambrian fossils.

From Science Magazine • May 1, 2024

Geologists have barely begun to describe the Precambrian eon, which spans Earth’s first 4bn years.

From The Guardian • May 30, 2019

Others divide the Precambrian into two eras, the very ancient Archean and the more recent Proterozoic.

From "A Short History of Nearly Everything" by Bill Bryson