Yesterday, a study in the journal Nature described fossils found in the Nuvvuagittuq belt in northeastern Canada that may just be the oldest known fossils in the world, formed between 3.77 and 4.28 billion years ago. However, as a story in the Washington Post on March 1, 2017 put it: ‘Findings like these are subject to intense scrutiny because they have potentially far-reaching implications for the study of early organisms on Earth and other planets.’
What is not under dispute is this specimen above, a hunk of rock called a Trendall Locality stromatolite, which was collected in Western Australia by University of Wisconsin–Madison geoscience professor John Valley. It’s on display at the UW–Madison Geology Museum (UW–Madison is home to the Wisconsin Astrobiology Research Consortium, part of a multi-institute NASA Astrobiology Institute initiative to study the origins of life on Earth and elsewhere). The stromatolites from this region are the oldest universally accepted evidence of life on Earth, dating back to roughly 3.4 billion years. As the rest of the caption reads: ‘Microbial colonies constructed this specimen in a lagoon-like setting that may have been exposed to air during low tide. Remarkably, the fossil layer at the Trendall Locality consists of just a few square meters of outcrop.’
It’s the job of science to question available evidence until it can be accepted beyond a reasonable doubt. As such, Valley says he is skeptical that the newly described fossil is as old as the authors claim. However, as a former postdoctoral student of Valley’s, Kenneth Willliford (now an astrobiologist at NASA’s Jet Propulsion Laboratory) told the Post: “It’s a very exciting set of observations carefully made … They may indeed have found something truly remarkable.”
Only time and further scientific inquiry will tell.