Species of <i>Dickinsonia</i> Sprigg from the Ediacaran of South Australia

An iconic member of the Ediacara Biota, Dickinsonia Sprigg is one few such taxa with multiple species. Here we use Gaussian finite mixture models to assess validity species distinctions for this genus. Our results indicate that five described from Member, South Australia are better classified as two based on approaches. Two different methods dimension reduction both provide strong support groups, overlapping but distinct models. The variable selection method produces most biologically realistic clusters, indicating can be primarily differentiated greater relative size anterior unit costata compared tenuis Glaessner & Wade. Despite differences in aspect ratio and number modules, regulated growth maintain overall shape. likelihood preservation a midline an irregular outer margin D. highlights differential structural integrity flexibility. Co-occurrence Member indicates occupied same environments temporal distribution. Smaller maximum average costata, combined higher abundance, may suggest comparatively shorter lifespan increased rates reproduction.