Creature thought to be world's oldest octopus isn't an octopus after all

World "Weird blob" creature thought to be the world's oldest octopus isn't an octopus after all. Here's what scientists found. April 9, 2026 / 9:38 AM EDT / CBS/AP Add CBS News on Google A prehistoric fossil previously thought to belong to the world's oldest octopus has been reclassified as something else, after scientists discovered the remains actually belonged to a different type of sea creature."It turns out the world's most famous octopus fossil was never an octopus at all," Thomas Clements, the lead researcher behind the new discovery and a zoology professor at England's University of Reading, said in a statement.Clements' newly published research concludes that fossilized remains listed by Guinness World Records as the earliest known octopus belong instead to a relative of a nautilus, a cephalopod with both tentacles and a shell.Clements told The Associated Press that the fossil, Pohlsepia mazonensis, has long been the subject of scientific debate."It's a very difficult fossil to interpret," he said. "To look at it, it kind of just looks like a white mush."If you look at it and you are a cephalopod researcher and you're interested in everything octopus, it does superficially look a lot like a deep-water octopus."The creature, a blob about the size of a human hand, was found in the Mazon Creek area of Illinois, about 50 miles southwest of Chicago, that is rich in fossils from a period before dinosaurs walked the Earth. Its identification by paleontologists as an octopus in 2000 upended ideas about the evolution of the eight-tentacled cephalopods, suggesting they emerged much earlier than previously thought. The next oldest-known octopus fossil is only about 90 million years old."It's a huge gap," Clements said. "And so that big gap got researchers sort of questioning, 'Is this thing actually an octopus?'"To solve the mystery of the "weird blob," Clements and his team used a synchrotron — which uses fast-moving electrons to create beams of light brighter...