Ediacara biota
Although these structures have only recently been named and systematically described, links between microbes and distinctive structures in sediments and sedimentary rocks have been suggested by several early workers. MISS have been identified in beds formed in the Archean and may be the oldest complete fossils on Earth. In the Ediacaran period, they are often associated with the preservation of fossils of the Ediacara biota; subsequent to this point their prevalence declines as a result of the Agronomic revolution