Lather, rinse, repeat. And it all started – at least, for complex life as we think of it today – with the Cambrian explosion. It was during this period, around 530 million years ago, that basically ...

A new study of ancient fossil trails pushes the origins of complex life deeper into Earth’s history, before the Cambrian Period began.

New fossil evidence suggests the Cambrian Explosion, once thought to have occurred 530 million years ago, may have begun 15 million years earlier.