The Ediacaran biota are the somewhat puzzling fauna of the Ediacaran period. This geological period was from 635–542 million years ago (mya), but the fossil biota was only from 575–542 mya. This was after a series of ice ages and just before the Cambrian period. The biota consists of soft-bodied multicellular organisms, probably animals, which left trace fossils in rocks of Ediacaran age.