The Divisions of Precambrian Time

You can find out more about the Precambrian by clicking on the chart below!

4.5 billion years ago, the Earth was born. Comprehending that vastness in time is no easy task. John McPhee, in his book Basin and Range, recounts a nice illustration of what this sort of time means. Stand with your arms held out to each side and let the extent of the earth's history be represented by the distance from the tips of your fingers on your left hand to the tips of the fingers on your right. Now, if someone were to run a file across the fingernail of your right middle finger, then the time that humans have been on the earth would be erased.

Nearly 4 thousand million years passed after the Earth's inception before the first animals left their traces. This stretch of time is called the Precambrian. To speak of "the Precambrian" as a single unified time period is misleading, for it makes up roughly seven-eighths of the Earth's history. During the Precambrian, the most important events in biological history took place. Consider that the Earth formed, life arose, the first tectonic plates arose and began to move, eukaryotic cells evolved, the atmosphere became enriched in oxygen -- and just before the end of the Precambrian, complex multicellular organisms, including the first animals, evolved.

Some good folks at Indiana State University have created a nice page on Paleomagnetism of the Precambrian. Using paleomagnetism data, one can work out recreations of continental placement during the Precambrian.

Prekambrium is an exhibit on the Precambrian at the Paleontology Museum in Oslo (text is in Norwegian).