Scientists in Canada have unearthed world’s oldest known fossils said to be at least 3.8 billion years old from Nuvvuagittuq Supracrustal Belt (NSB), Quebec, Canada.
Up until now scientists believed that the old known fossils of living organisms were dated some 3,460 million years ago, but that hasn’t been confirmed as there is a faction of scientists who believe that alleged fossils may not be or organic origin. However, the latest study led by scientists from University College London have unearthed evidence that undoubtedly point to organic fossils.
The team unearthed tiny filaments and tubes formed by bacteria that could have lived on iron. The team looked at ways the tubes and filaments, made of haematite – a form of iron oxide or ‘rust’ – could form through methods that are not of biological origin including temperature and pressure changes in the rock during burial of the sediments. Despite all their attempts they were unable to find any possibility that could point to non-biological origin of these fossils. Scientists concluded that there was only one possible explanation behind the formation of these filaments and tubes – biological origin or in other words microorganisms.
Scientists say that the haematite structures they have discovered have the same characteristic branching of iron-oxidising bacteria that are found near other hydrothermal vents today. Scientists found these structures alongside graphite and minerals like apatite and carbonate, which are found in biological matter including bones and teeth and are frequently associated with fossils.
Another evidence that hints at presence of life is that these mineralised fossils are associated with spheroidal structures that usually contain fossils in younger rocks, suggesting that the haematite most likely formed when bacteria that oxidised iron for energy were fossilised in the rock.
The filaments and tubes that scientists unearthed in their latest study are composed of the minerals expected to form from putrefaction, and have been well documented throughout the geological record, from the beginning until today. Scientists say that the fact that they were found in one of the oldest known rock formations indicate that they are direct evidence of oldest life forms on Earth.