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 encompasses 86 percent of the history of Earth. As its name implies, this includes all of geological time prior to the Cambrian period. Hadean Era (4,550-3,850 mya) The Precambrian ...

Paleontologists now know that the Precambrian actually did swarm with ... Any sedimentary rocks that formed before life appeared on Earth would have the high C-13 ratio of a volcanic origin.

In a study published in Precambrian Research Monday by scientists ... could suggest a "two-step" evolution to complex life on Earth. The evidence was found in marine sedimentary rocks from 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 ...