A fresh look at Dickinsonia: Removing it from Vendobionta

Abstract

The Ediacaran Dickinsonia is well-known for being the only fossil to be assigned to many phyla, ranging from lichens, Cnidaria, Platyhelminthes, Annelida, and a phylum of its own to a nonmetazoan kingdom. A new specimen from the Ediacaran fine-grained sandstone on the Winter Coast of the White Sea in northern Russia, which has an age of similar to 555 million years ago, preserved convincing internal anatomies of definite animals, comparable with meridional canals of extant ctenophores (comb jellies). Additionally, we reconsidered Dickinsonia as a biradially symmetrical animal rather than a bilateral one as previously thought. The animal nature of Dickinsonia is, thus, well established and its affinities are most probably allied to ctenophores. This research is not only removing Dickinsonia from Vendobionta, but also bringing the fossil record of ctenophores forward to 20 million years before the Cambrian "explosion".