Discoidal Impressions and Trace-Like Fossils More Than 1200 Million Years Old

+ See all authors and affiliations

Science  10 May 2002:
Vol. 296, Issue 5570, pp. 1112-1115
DOI: 10.1126/science.1070166

You are currently viewing the abstract.

View Full Text


The Stirling Range Formation of southwestern Australia contains discoidal impressions and trace-like fossils in tidal sandstones. The various disks have previously been linked to the Ediacaran biota, younger than 600 million years old. From this unit, we report U-Th-Pb geochronology of detrital zircon and monazite, as well as low-grade metamorphic monazite, constraining the depositional age to between 2016 ± 6 and 1215 ± 20 million years old. Although nonbiological origins for the discoidal impressions cannot be completely discounted, the structures resembling trace fossils clearly have a biological origin and suggest the presence of vermiform, mucus-producing, motile organisms.

  • * To whom correspondence should be addressed. E-mail: brasmussen{at}

View Full Text

Related Content