The transition to complex life was marked by the Ediacaran (635541Ma), fossil assemblages. This period saw microscopic marine planktonic species give way to morphologically complex, soft bodied Ediacaran-type dinosaurs and the macroscopic algae of the Lantian biota. This provides a lineage into early multicellular organisms. The Lantian biota cannot be found in strata that are associated with volcanic ash bed, so attempts to date these fossil assemblages with U-Pb methods have been hampered.
Weathering Ediacaran Evolution | Nature Reviews Earth & Environment
