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A New Enigmatic, Tubular Organism from the Ediacara Member, Rawnsley Quartzite, South Australia

Published online by Cambridge University Press:  15 October 2015

Lucas V. Joel
Affiliation:
Department of Earth Sciences, University of California, Riverside, CA 92521, USA,
Mary L. Droser
Affiliation:
Department of Earth Sciences, University of California, Riverside, CA 92521, USA,
James G. Gehling
Affiliation:
South Australian Museum, Adelaide, South Australia, Australia 5000

Abstract

Here we reconstruct a new tubular, serially divided organism with a bilateral morphology from the Ediacaran of South Australia. The organism, Plexus ricei new genus new species, was a broadly curving tube that resided on the Ediacaran seafloor. Plexus ricei individuals range in size from 5 to 80 cm long and 5 to 20 mm wide, and are comprised of two main components: a rigid median tubular structure and a fragile outer tubular wall. Plexus ricei is preserved as an external mold on bed soles, and as a counterpart cast on bed tops in sandstones interpreted to represent deposition between storm and fairweather wave-base. The phylogenetic affinities of P. ricei are uncertain; P. ricei symmetry implies a bilaterian origin, but a lack of defined anterior and posterior ends precludes definitive assignment.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Cohen, P. A., Bradley, A., Knoll, A. H., Grotzinger, J. P., Jensen, S., Abelson, J., Hand, K., Love, G., Metz, J., McLoughlin, N., Meister, P., Shephard, R., Tice, M., and Wilson, J. P. 2009. Tubular compression fossils from the Ediacaran Nama Group, Namibia. Journal of Paleontology, 83:110122.Google Scholar
Droser, M. L., Gehling, J. G., and Jensen, S. R. 2005. Ediacaran trace fossils: true and false, p. 125138. In Briggs, D. E. G. (ed.), Evolving Form and Function: Fossils and Development. Proceedings of a Symposium Honouring Adolph Seilacher for his Contributions to Paleontology in Celebration of his 80th Birthday. Peabody Museum of Natural History, Yale University, New Haven, Connecticut.Google Scholar
Droser, M. L., Gehling, J. G., and Jensen, S. R. 2006. Assemblage paleoecology of the Ediacara biota: The unabridged edition? Palaeogeography, Palaeoclimatology, Palaeoecology, 232:131147.Google Scholar
Droser, M. L. and Gehling, J. G. 2008. Synchronous aggregate growth in an abundant new Ediacaran tubular organism. Science, 319:16601662.Google Scholar
Ekdale, A. A., Bromley, R. G., and Pemberton, S. G. 1984. Ichnology: The use of trace fossils in sedimentology and stratigraphy. SEPM Short Course 15:317.Google Scholar
Gehling, J. G. 1999. Microbial mats in terminal Proterozoic siliciclastics: Ediacaran death masks. Palaios, 14:4057.Google Scholar
Gehling, J. G. 2000. Environmental interpretation and a sequence stratigraphic framework for the terminal Proterozoic Ediacara Member within the Rawnsley Quartzite, South Australia. Precambrian Research, 100:6595.Google Scholar
Gehling, J. G., Droser, M. L., Jensen, S., and Runnegar, B. N. 2005. Ediacara organisms: relating form and function, p. 4366. In Briggs, D. E. G. (ed.), Evolving Form and Function: Fossils and Development. Proceedings of a Symposium Honouring Adolph Seilacher for his Contributions to Paleontology in Celebration of his 80th Birthday. Peabody Museum of Natural History, Yale University, New Haven, Connecticut.Google Scholar
Gehling, J. G. and Droser, M. L. 2009. Textured organic surfaces associated with the Ediacara biota in South Australia. Earth-Science Reviews, 96:196206.CrossRefGoogle Scholar
Gehling, J. G. and Droser, M. L. 2012. Ediacaran stratigraphy and the biota of the Adelaide Geosyncline, South Australia. Episodes-Newsmagazine of the International Union of Geological Sciences, 35:236.Google Scholar
Gehling, J. G. and Droser, M. L. 2013. How well do fossil assemblages of the Ediacara Biota tell time? Geology, 41:447450.Google Scholar
Glaessner, M. F. 1969. Trace fossils from the Precambrian and basal Cambrian. Lethaia, 2:369393.CrossRefGoogle Scholar
Jensen, S., Droser, M. L., and Gehling, J. G. 2006. A critical look at the Ediacaran trace fossil record, p. 115157. In Xiao, S. and Kaufman, A. J. (eds.), Neoproterozoic Geobiology and Paleobiology. Springer, Netherlands.CrossRefGoogle Scholar
Narbonne, G. M. 1998. The Ediacara biota: A terminal Neoproterozoic experiment in the evolution of life. GSA Today, 30:627630.Google Scholar
Preiss, W. V. 1987. Precambrian palaeontology of the Adelaide Geosyncline, p. 283313. In Drexel, J. F. (ed.), The Adelaide Geosyncline–Late Proterozoic Stratigraphy, Sedimentology, Palaeontology and Tectonics. South Australia Geological Survey Bulletin 53.Google Scholar
Sappenfield, A., Droser, M. L., and Gehling, J. G. 2011. Problematica, trace fossils, and tubes within the Ediacara Member (South Australia): Redefining the Ediacaran trace fossil record one tube at a time. Journal of Paleontology, 85:256265.Google Scholar
Tacker, R. C., Martine, A. J., Weaver, P. G., and Lawver, D. R. 2010. Trace fossils versus body fossils: Oldhamia recta revisited. Precambrian Research, 178:4350.Google Scholar
Waggoner, B. 2003. The Ediacaran biota in space and time. Integrative and Comparative Biology, 32:104113.Google Scholar
Xiao, S., Yuan, X., Steiner, M., and Knoll, A. 2002. Macroscopic carbonaceous compressions in a terminal Proterozoic shale: A systematic reassessment of the Miaohe Biota, south China. Journal of Paleontology, 76:347376.Google Scholar
Xiao, S. and Laflamme, M. 2009. On the eve of animal radiation: Phylogeny, ecology and evolution of the Ediacara biota. Trends in Ecology and Evolution, 24:3140.Google Scholar