New insights into ancient life: the Ediacara biota through the windows of taphonomy and fluid mechanics

Abstract

The Neoproterozoic Ediacara biota (~571-539 Ma) is an enigmatic group of soft-bodied multicellular organisms that represents the first radiation of complex, eukaryotic macroscopic life. Their bizarre morphologies and unique death mask type preservation have hampered our ability to reconstruct their individual paleoecologies and place them on a tree of life. To better understand their unique preservation, I perform a series of taphonomic experiments to constrain the role of iron, a key ingredient in Ediacaran death mask type preservation. These results represent the first Fe–S veneers precipitated under laboratory conditions, and suggest Ediacaran death mask preservation is largely constrained by a balance of low levels of iron, necessary seawater sulfate, and pivotal organic nucleation sites. I then use fluid dynamics modeling to reconstruct a suspension feeding ecology and gregarious behavior for the modular Ediacaran Ernietta. My results demonstrate the aggregation of individual Ernietta into small populations was likely beneficial for feeding efficiency, which represents one of the oldest examples of a commensal behavior in the fossil record. Lastly, I review pivotal advancements in Ediacaran paleontology through the window of fluid physics, detail more realistic and sophisticated approaches for computational fluid dynamics analyses in paleontological studies, and outline future research directions for reconstructing Ediacaran paleoecology using fluid dynamics.