300-Million-Year-Old Fossil Misidentified as Earliest Octopus Now Revealed as Nautilus Relative

A fossil discovered in Illinois, estimated to be 300 million years old, was previously thought to be the oldest octopus but has now been reclassified as a relative of the nautilus. This new research, led by Thomas Clements from the University of Reading, was published on April 8 in the Proceedings of the Royal Society B: Biological Sciences. Researchers used synchrotron imaging to analyze a radula with at least 11 teeth per row, which is not typical for octopuses. The fossil, named Pohlsepia mazonensis, was misidentified 25 years ago due to its decomposition. Adam Millward mentioned that the octopus title will be retired by Guinness World Records. The study suggests octopuses emerged during the Jurassic period, between 145 and 201.3 million years ago, while this specimen offers the oldest evidence of soft tissue from a nautiloid. Alexander Pohle from Ruhr University Bochum praised the study for revealing the fossil's accurate identity.