Scientists Find 3 Billion Year Old Plankton Microfossils

Posted on June 7, 2013

Plankton Microfossils

Scientists have found 3 billion year old plankton microfossils in marine sediment rocks from the Farrel Quartzite in Western Australia. The spindle-shaped microfossils are 20 to 60 microns in length. This is about the size of fine sand.

Christopher H. House, professor of geosciences, Penn State, and lead author of the study, said in a release, "It is surprising to have large, potentially complex fossils that far back."

To determine if these inclusions in the rocks were biological in origin, the researchers looked at 15 different samples of Farrel Quartzite and determined their stable carbon isotope ratios. The percentage of carbon 13 in the microfossils was indicative of material produced by biological processes. The scientists also found that the carbon 13 percentage in the background organic matter in the surrounding rock was different from that of the microstructures.

In a research paper published in Geology, the scientists report, "When considered along with published morphological and chemical studies, these results indicate that the FQ microstructures are bona fide microfossils, and support the interpretation that the spindles were planktonic."

Photo: Christopher H. House/Penn State