Taxa, turnover and taphofacies: a preliminary analysis of facies-assemblage relationships in the Ediacara Member (Flinders Ranges, South Australia)

Abstract

The Ediacara Member of the Flinders Ranges (South Australia) preserves body and trace fossils of the Ediacara biota. Fossils span five lithofacies representative of a range of shallow-marine environments and are preserved as in situ and transported material. Previous work has demonstrated a relationship between paleoenvironment and taxa at the Nilpena fossil site. We expand the analysis to include facies-taxa data from a further nine localities across the Flinders Ranges to assess if the taxa–paleoenvironment relationship is site specific or valid at a regional scale. The new analysis demonstrates that the distribution of taxa within the lithofacies, as a proxy for paleoenvironment, is non-random. This preliminary analysis presents a beta diversity-like spatial turnover across the range of shallow marine Ediacaran environments, and demonstrates taxonomic assemblages are specific to given paleoenvironmental zones. These assemblages are consistent over a broad spatial extent and also a presumed temporal distribution. This specificity indicates that a marked sensitivity to environmental parameters was present in these communities, as demonstrated by the non-random distribution of taxa and spatial turnover of biotic assemblage throughout the gradational environments of the Ediacara Member. This study highlights the variability and heterogeneity that is a characteristic of shallow marine settings, and offers a novel approach to the future investigation of the relationship between Ediacaran environments and taxa assemblages.