The ‘oldest fossil octopus’ is probably another animal
The over 300-million-year-old Pohlsepia may be a nautilus called Paleocadmus
A Paleocadmus nautilus decays on the seafloor more than 300 million years ago in what will become Illinois. The separated shell is visible in the background. Other animals are visible, such as the marine worm Esconites zelus (foreground) and Bandringa rayi, a relative of sharks (back left).
Dr. Thomas Clements, University of Reading