More than 541 million years ago, during the Precambrian Eon, life existed in a quiet gloom ... but they never knew whether that looming shadow was a friend or foe. Then, at the beginning of the ...

All animal evolution for the last half billion years has come from tinkering with these Cambrian body plans. Then, between about 570 and 530 million years ago, another burst of diversification ...

The Precambrian eon is vast, almost unimaginably so ... As its name implies, this includes all of geological time prior to the Cambrian period. Hadean Era (4,550-3,850 mya) The Precambrian's ...

Something dramatic happened about 500 million years ago called the Cambrian "explosion," during which an incredible diversity ...

The Phanerozoic Eon began around 540 million years ago, marked by the Cambrian Explosion—a time when complex, hard-shelled ...