In 2017, researchers initially thought they had found ancient trace fossils from small marine animals dating back 542 to 555 million years. However, new research published in Gondwana Research casts doubt on this interpretation, suggesting the filaments are actually algae or bacteria. Advanced imaging techniques revealed cellular structures aligning more closely with microbial life rather than animal traces. This aligns with historical context, as low atmospheric oxygen levels around 540 million years ago likely could not support small invertebrates.
Bruno Becker Kerber, lead author of the new study, emphasized that the preserved cell structures indicate a microbial origin. Even though these findings challenge the previous interpretation, Luke A. Parry, who led the 2017 study, acknowledges the importance of reanalyzing fossils with modern techniques.
The research, which used advanced imaging methods like microtomography and Raman spectroscopy, also identified new samples with similar characteristics. Some of the microfossils are notable for being among the largest recorded bacteria and algae, indicating a diverse microbial community.
Parry highlighted that varying fossil structures can sometimes appear similar due to preservation, and ongoing discoveries, including new fossil sites in China and Namibia, may require a reevaluation of the Cambrian Explosion’s timeline. The small size of these fossils continues to challenge analytical capabilities, leaving room for further insight into early life forms.
