The nature of vendobionts

The notion that the majority of Ediacaran fossils do not represent stem groups to modern metazoan phyla is now increasingly accepted. Nevertheless, the further claim of the vendobiont hypothesis needs to be elaborated: that these large and seemingly complex organisms were not truly multicellular. Arguments for interpreting vendobionts as an extinct class of rhizopodan Protozoa are: (1) negative allometry of the quilts; (2) presence of a loosely englutinated, but sandy fill skeleton similar to the xenophyophorian stercomare; (3) a disparity of designs and life-styles that would be incompatible with metazoan bauplans and feeding strategies; (4) unusual patterns of regeneration; (5) resting traces of some mobile, epibenthic species.