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 ...

Prehistoric time line, geologic time scale, photos, facts, maps ... rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates ...

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 ...