The life and times of Pteridinium simplex

Pteridinium simplex is an iconic erniettomorph taxon best known from late Ediacaran successions in South Australia, Russia, and Namibia. Despite nearly 100 years of study, there remain fundamental questions surrounding the paleobiology and -ecology of this organism, including it’s life position relative the sediment-water interface, and how it fed and functioned within benthic communities. Here, we combine a re-description of specimens housed at the Senckenberg Forschungsinstitut und Naturmuseum Frankfurt with field observations of fossiliferous surfaces to constrain the life habit of Pteridinium and gain insights into the character of benthic ecosystems shortly before the beginning of the Cambrian. We present paleontological and sedimentological evidence suggesting that Pteridinium was semi-infaunal and lived gregariously in aggregated communities, preferentially adopting an orientation with the long-axis perpendicular to the prevailing current direction. Using computational fluid dyna...