Ancient fossil once hailed as the oldest octopus reclassified as a nautiloid
A 300-million-year-old fossil long considered the world’s oldest octopus (Pohlsepia mazonensis) has been reclassified as a nautiloid (Paleocadmus pohli) after synchrotron imaging revealed internal features incompatible with octopuses, overturning about 150 million years of cephalopod timing and reshaping our understanding of when octopuses first appeared.