Ediacaran stratigraphy and the biota of the Adelaide Geosyncline, South Australia

The Neoproterozoic and Cambrian sequences of the Mount Lofty and Flinders ranges of South Australia record a crucial interval in the evolution of life and environments on Earth. This paper summarises the key characteristics of the Ediacaran succession of the Adelaide Geosyncline. Recent interest in the Neoproterozoic and Cambrian successions on all continents has been driven by a quest to better understand the causes and effects of the size revolution that saw the advent of multicellular organisms in the ocean. The principal role of the Neoproterozoic Subcommission has been to determine unique time boundaries that reflect evolutionary changes in the Earth system. Utilisation of a combination of geochemical, paleobiological and stratigraphic events, to offset the limitations of the Neoproterozoic paleontological record, is required to bracket this interval of Earth history. Fossils of the Cryogenian, Ediacaran and Cambrian document a series of unexpected quantum leaps in the size and diversity of life.