Ancient Octopus Fossil Reclassified as Nautiloid, Redrawing Cephalopod History

New synchrotron imaging of the 300-million-year-old fossil Pohlsepia mazonensis shows it is a nautiloid relative, not an octopus. The fossil reveals a nautilus-like radula with 11 tooth-like elements per row and other features, leading researchers to reclassify the find and push octopus origins into the Mesozoic era (late Jurassic at latest). Published in Proceedings of the Royal Society B, the study also provides the oldest soft-tissue evidence of a nautiloid, reshaping our understanding of cephalopod evolution.