The fossil was initially discovered at a website at Mazon Creek within the US state of Illinois, and was formally named and described in 2000.
At the time, scientists thought the fossil confirmed eight arms, fins and different options typical of an octopus.
However, scientists on the University of Reading determined to make use of the most recent expertise to have a look contained in the fossil.
They used beams of sunshine, brighter than the solar, to scan the fossil, which revealing new particulars throughout the rock.
They found tiny enamel that matched these of a fossil nautiloid that was discovered on the identical website within the US, that means the fossil wasn’t really an octopus.
Experts say these findings imply that knowledge now helps the idea that octopuses first appeared throughout the Jurassic interval, a lot later than beforehand thought.
Lead creator of the research, Dr Thomas Clements, from the University of Reading defined: “It turns out the world’s most famous octopus fossil was never an octopus at all.
“It was a nautilus relative that had been decomposing for weeks earlier than it grew to become buried and later preserved in rock, and that decomposition is what made it look so convincingly octopus-like.
“Sometimes, re-examining controversial fossils with new techniques reveals tiny clues that lead to really exciting discoveries,” Dr Clements added.
