A pink sponge, photographed at an aquarium today, is not unlike one of the first life forms that appeared in the Precambrian era. Photograph by Joel Sartore, National Geographic Photo Ark The ...

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 ...

British evolutionary biologist and zoologist, Richard Dawkins has reacted to the UK Supreme Court ruling on the definition of ...

1. Pre-Cambrian Era : This is the longest era of the classification of the history of earth. It marks the origin of earth. This era ended 570 million years ago. The chief events that took place in ...

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 ...

More extensive Precambrian finds ... that skeletonized creatures of the Cambrian period, long thought by scientists to be the first multicellular animals, had predecessors. Debate continues ...