• DOI:10.1080/03115510701484705
• Corpus ID: 17181699

Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil

@article{Retallack2007GrowthDA,
  title={Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil},
  author={Gregory J. Retallack},
  journal={Alcheringa: An Australasian Journal of Palaeontology},
  year={2007},
  volume={31},
  pages={215 - 240}
}

• G. Retallack
• Published 1 September 2007
• Environmental Science
• Alcheringa: An Australasian Journal of Palaeontology

Retallack, G.J., September, 2007. Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil. Alcheringa 31, 215-240. ISSN 0311-5518. Dickinsonia is a Neoproterozoic, Ediacaran fossil, variously considered a polychaete, turbellarian or annelid worm, jellyfish, polyp, xenophyophoran protist, lichen or mushroom. Its preservation as unskeletonized impressions in quartz sandstones has been attributed to a Neoproterozoic regime of aerobic decay less effective than today, microbial pyritization much nearer the surface than today, or agglutinate-mineralization as in xenophyophorans. However, the great variation in thickness independent of width or length of South Australian Dickinsonia is evidence of decay like the wilting of a fossil leaf, lichen or mushroom, but unlike clotting and distortion during decay, wilting or osmotic shrinkage of modern and fossil worms and jellyfish. Decayed specimens of Dickinsonia arrayed in arcs have been interpreted as slime trails or tumble tracks, but can also be interpreted as rhizinous bases of decayed crustose lichens or mushrooms arranged in fairy rings. Dickinsonia is interpreted to be sessile because adjacent specimens show reaction rims indicative of competitive interaction, and because no overlapping well-preserved specimens have ever been found. Folded and bent Dickinsonia reveal firm attachment and limited flexibility, but no brittle deformation indicative of pyritic, sideritic or calcitic ‘death masks’ or xenophyophoran agglutinate skeletons. Dickinsonia was resistant to compaction by overburden, like fossil lichens such as Spongiophyton and Thucomyces, and more compaction-resistant than fossil logs, jellyfish or worms. Dickinsonia also shows indeterminate growth like lichens, fungi, plants, xenophyophorans and colonial animals. Growth, decay and burial compaction of Dickinsonia were more like those of plants, lichens and fungi, than of worms, jellyfishes or anemones. G.J. Retallack [[e-mail]], Department of Geological Sciences, University of Oregon. Eugene, OR 97403-1272, USA; received 18.11.05, revised 23.3.06.