is not unlike one of the first life forms that appeared in the Precambrian era. Photograph by Joel Sartore, National Geographic Photo Ark The earliest multicelled animals that survived the ...

During the Proterozoic era, oxygen produced by photosynthesizing ... So what exactly were these highly diverse Precambrian creatures? Plants, animals, or of another kingdom entirely?

Despite being the largest and most diverse group of animals on the planet ... ecdysozoan and the only one known from the Precambrian era. Lead researcher Ian Hughes, a Ph.D. candidate from ...