Letters to Nature

Nature 388, 868-871 (28 August 1997) | ; Received 23 October 1996; Accepted 27 May 1997

The Late Precambrian fossil Kimberella is a mollusc-like bilaterian organism

Mikhail A. Fedonkin1 and Benjamin M. Waggoner

  1. Paleontological Institute, Russian Academy of Sciences, ul. Profsoyuznaya 123, Moscow 117647, Russia
  2. Department of Integrative Biology, University of California, Berkeley, California 94720, USA

Correspondence to: Correspondence and requests for materials should be addressed to B.M.W. (e-mail: Email: bmw@uclink2.berkeley.edu).

The fossil Kimberella quadrata was originally described from late Precambrian rocks of southern Australia1. Reconstructed as a jellyfish2, it was later assigned to the cubozoans ('box jellies'), and has been cited as a clear instance of an extant animal lineage present before the Cambrian3, 4, 5, 6, 7. Until recently, Kimberella was known only from Australia, with the exception of some questionable north Indian specimens8. We now have over thirty-five specimens of this fossil from the Winter Coast of the White Sea in northern Russia. Our study of the new material does not support a cnidarian affinity. We reconstruct Kimberella as a bilaterally symmetrical, benthic animal with a non-mineralized, univalved shell, resembling a mollusc in many respects. This is important evidence for the existence of large triploblastic metazoans in the Precambrian and indicates that the origin of the higher groups of protostomes lies well back in the Precambrian.