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 ...

This tiny fossil, measuring just a few centimeters, is significant as it is the oldest confirmed ecdysozoan and the only one known from the Precambrian era. Lead researcher Ian Hughes, a Ph.D. can ...

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 ...

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, particularly those discovered ... the period that closes the Proterozoic era. If they were wiped out by an extinction event, changes in sea level or lowered ...