Precambrian time covers the vast bulk of the Earth's history, starting with the planet's creation about 4.5 billion years ago and ending with the emergence of complex, multicelled life-forms ...

The Precambrian eon is vast, almost unimaginably so. In fact, before some fossil discoveries were made late in the 20th century, it was considered unknowable -- evolution's dark ages. The ...

A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates ...