This daily feast-and-famine cycle in oxygen availability created an intense physiological challenge for early animals, ...

dramatically. It was the time of the Cambrian Explosion, an eruption of life when Earth’s very first animals began appearing in the fossil record — the ancestors of all major animal groups ...

The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today. Among them were the chordates, to which vertebrates (animals with backbones ...

Experts disagree about just when the intricate patterns of burrowing creatures first appeared, but by any judgment those traces signaled a big change from the Ediacaran to the Cambrian.

More than 500 million years ago, something in the ocean changed. Some creatures evolved to build their own hard-shelled ...

An exception was the mysterious "small shelly fauna" -- minute shelled animals that are hard to categorize -- that left abundant fossils in the early Cambrian. Recently, minute fossil embryos ...

Some animals could likely tell the difference between light and dark, but they never knew whether that looming shadow was a friend or foe. Then, at the beginning of the Cambrian Period, life opened ...

But during the Cambrian period, creatures with complex body structures emerged. Scientists who study such things call this the "Cambrian explosion" because it was a period of rapid evolution.

All the Latest Game Footage and Images from Cambrian Dawn Journey to a time long forgotten... In this thrilling underwater world of strange and beautiful creatures, only the strongest species will ...

An exception was the mysterious "small shelly fauna" -- minute shelled animals that are hard to categorize -- that left abundant fossils in the early Cambrian. Recently, minute fossil embryos ...