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Scratch Traces of Large Ediacara Bilaterian Animals

Published online by Cambridge University Press:  15 October 2015

James G. Gehling ,
Bruce N. Runnegar  and
Mary L. Droser
James G. Gehling
Affiliation:
South Australian Museum, Division of Natural Science, North Terrace, Adelaide, South Australia 5000 University of Adelaide, North Terrace, South Australia 5000, Australia,
Bruce N. Runnegar
Affiliation:
Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095-1567, USA,
Mary L. Droser
Affiliation:
Department of Earth Sciences, University of California, Riverside, CA 92521, USA,
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Abstract

Ediacara fan-shaped sets of paired scratches Kimberichnus teruzzii from the Ediacara Member of the Rawnsley Quartzite, South Australia, and the White Sea region of Russia, represent the earliest known evidence in the fossil record of feeding traces associated with the responsible bilaterian organism. These feeding patterns exclude arthropod makers and point to the systematic feeding excavation of seafloor microbial mats by large bilaterians of molluscan grade. Since the scratch traces were made into microbial mats, animals could crawl over previous traces without disturbing them. The trace maker is identified as Kimberella quadrata, whose death masks co-occur with the mat excavation traces in both Russia and South Australia. The co-occurrence of animals and their systematic feeding traces in the record of the Ediacara biota supports previous trace fossil evidence that bilaterians existed globally before the Cambrian explosion of life in the ocean.

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Research Article
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Journal of Paleontology , Volume 88 , Issue 2 , March 2014 , pp. 284 - 298
Copyright
Copyright © The Paleontological Society 

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