US EditionEarliest Known Octopus Is Not an Octopus After All
Synchrotron scans found 11 tooth elements and a radula, showing the fossil matches nautiloid relatives and pushing octopus origins later.
- On Wednesday, April 8, 2026, researchers published findings in the Proceedings of the Royal Society reclassifying the 300 million year old fossil Pohlsepia as a nautiloid relative rather than an octopus.
- Originally discovered in Illinois and described in 2000, scientists interpreted the fossil's decayed features as evidence of an octopus, pushing the known origin of octopuses back by at least 150 million years.
- Thomas Clements and his team used synchrotron imaging to uncover a radula with at least 11 teeth, which matched those of the nautiloid Paleocadmus rather than octopuses, which typically have seven or nine.
- This reclassification removes Pohlsepia from the Guinness Book and World Records as the oldest octopus, while extending the nautiloid soft tissue record back by around 220 million years.
- The discovery redraws the cephalopod family tree, suggesting octopuses appeared much later during the Jurassic period, while the split between octopuses and their ten-armed relatives occurred in the Mesozoic era.
35 Articles
35 Articles
A fossil of about 300 million years, considered for decades to be the oldest octopus in the world, changed its identity after a new scientific analysis.The specimen, known as Pohlsepia maconensis, corresponds in fact to a relative of the nautils, a group of cephalopods with external shell that still exists.The fossil was described in 2000 from a finding in Illinois, United States. At that time, researchers classified it as a primitive octopus. T…
A Row of Hidden Teeth Rewrites Story of the Octopus
The creature that swam into the Guinness Book of Records as the planet's earliest known octopus just got its title revoked. New high-powered scans of the 300-million-year-old fossil Pohlsepia mazonensis reveal it's not an octopus at all, but a relative of today's nautilus—with a set of tiny teeth being...
The development history of octopus has to be rewritten: an alleged sensation turns out to be a confusion with a sea animal with an outer shell. The number of rows of teeth inside the rock provides the decisive proof.
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