300-Million-Year-Old 'Oldest Octopus' Fossil Reclassified as Nautilus Relative

A fossil long celebrated as the world's oldest known octopus has been dethroned from that title after scientists determined it belongs to an entirely different branch of the cephalopod family tree. The creature, estimated to be around 300 million years old, is now believed to be a relative of the nautilus rather than an ancestor of modern octopuses.

The groundbreaking reanalysis was led by Thomas Clements, a zoology lecturer at the University of Reading. His team examined key anatomical features of the fossil and found that earlier classifications had been based on misidentified structures, leading researchers astray for years.

Cephalopods — the group that includes octopuses, squids, nautiluses, and cuttlefish — have a long and complex evolutionary history. Distinguishing between ancient relatives of these animals is notoriously difficult, as soft body parts rarely survive the fossilization process, leaving scientists with only partial evidence to work from.

The fossil in question had previously been held up as a landmark discovery in understanding how octopuses evolved. Its reclassification not only strips it of its record-holding status but also forces paleontologists to reconsider the timeline of octopus evolution and when the earliest true octopuses first appeared in the fossil record.

Clements and his colleagues used advanced imaging techniques and comparative anatomy to build their case, identifying shell characteristics more consistent with nautiloid lineage than with octopus ancestors. The findings underscore how new technologies continue to reshape our understanding of prehistoric life.

The study serves as a reminder of how dynamic and self-correcting science can be. As analytical tools improve and researchers revisit historic specimens with fresh eyes, long-accepted conclusions can be overturned, painting a more accurate picture of life on Earth hundreds of millions of years ago.