Dating the Lantian Biota.
Fossils from the Ediacaran Period record a remarkable transition from a world in which there were almost no multicellular organisms to one in which such organisms dominated almost all marine ecosystems. Deposits from the Lower Ediacaran are dominated by the Acritarchs, a diverse group of single-celled marine Algae which may-or-may-not represent a single taxonomic group. Deposits from the Upper Ediacaran produce a range of complex fossils, apparently of soft-bodied organisms of uncertain affinities. One of the earliest macro-fossil producing deposits is the Lantian Formation of South China, a deep-marine basinal black shale which produces a series of fossils of increasing complexity, assumed to have affinities to Algae and Animals, providing insight into the earliest stages in the development of these multicellular organisms.