Smothering of microbial mats by macrobiota: implications for the Ediacara biota

Recent advances in understanding the preservation of the soft-bodied Neoproterozoic Ediacara biota have centred upon the role of microbes in casting the morphologies of static or dead macrobiota on the Precambrian sea floor. This experimental study explores the preservational effects brought about by the passive movement of dead macro-organisms upon a pre-established marine microbial mat under laboratory conditions. This demonstrates the potential for making multiple impressions of body tissues on the surface of microbial mats by means of passive transport alone. This throws doubt on the evidence for active feeding in Ediacaran fossils such as Dickinsonia and Yorgia.