The Precambrian fossil known as Dickinsonia dates back as far as 600 million years ago, and can be found in regions of Russia and Australia (Virtual Fossil Museum). Many of these fossil’s indentations are found in various rocky structures such as sandstone and can range in length to over a meter. The structure and classification of the Dickinsonia organisms are still debated among scientist today because of their shared characteristics with Annelids, Cnidarians, and other organisms (Antcliffe and McLoughlin 2008). These fossils display bilateral symmetry due to the extension of what appears to be segmented structures that extend out from a central line. These organisms had very primitive circulation systems, digestive tracts and even muscles in between all their segments that allowed them to dig into sandy or muddy surfaces, which possibly caused the perfect preservation of these extinct organisms (Runnegar 1982). The structures in some fossils found in Russia and Australia differ in shape and size; however the same overall shape and composition remain intact in all Dickinsonia fossils.

Page by Pete Calomiris

Antcliffe, J. and N. McLoughlin, N. 2008. Deciphering the fossil evidence for the Origins of Life, Origins of Animals: Common problems in different worlds. In "From Fossils to Astrobiology" M. Walsh and J. Sekbach (Eds) Springer, 211-229.

Runnegar, B. 1982. Oxygen requirements, biology and phylogenetic significance of the late Precambrian worm Dickinsonia, and the evolution of the burrowing habit. Alcheringa 6-3: 223-239.

The Virtual Fossil Museum. Dickinsonia Vendian Fossil. Accessed Januray 2010.