A new study of ancient microfossils has revealed that the pre-historic Earth was a pretty foul smelling place.
Researchers examining a microfossil assemblage found near Canada's Lake Superior shows that ancient microbes fed on the organism Gunflintia.
The Gunflinta were concentrated in sheaths, and an examination of the sheaths revealed not only perforations that indicated the sheaths were being eaten, but also the presence of iron sulfide (pyrite or 'fool's gold') in the place of the organic material where the bacteria ate into the sheaths.
Iron sulfate is a visible indicator of bacterial waste product. These bacteria consumed the Gunflinta sheaths for every meal, leaving behind a big stink after their meal.
"In fact we've all experienced modern bacteria feeding in this way as that's where that 'rotten egg' whiff of hydrogen sulfide comes from in a blocked drain. So, rather surprisingly, we can say that life on earth 1,900 million years ago would have smelled a lot like rotten eggs," said Martin Brasier of Oxford University's Department of Earth Sciences, according to Discovery News.
'Whilst there is chemical evidence suggesting that this mode of feeding dates back 3,500 million years, in this study for the first time we identify how it was happening and 'who was eating who," Brasier said.
The study. "Nanoscale analysis of pyritized microfossils reveals differential heterotrophic consumption in the ∼1.9-Ga Gunflint chert," is published in this week's Proceedings of the National Academy of Sciences (PNAS).