{"id":523501,"date":"2026-04-10T15:09:14","date_gmt":"2026-04-10T15:09:14","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/523501\/"},"modified":"2026-04-10T15:09:14","modified_gmt":"2026-04-10T15:09:14","slug":"300-million-year-old-fossil-thought-to-be-worlds-oldest-octopus-turns-out-to-be-a-completely-different-species","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/523501\/","title":{"rendered":"300 Million-Year-Old Fossil Thought to Be World’s Oldest Octopus Turns Out to Be a Completely Different Species"},"content":{"rendered":"

A famous fossil once considered the world\u2019s oldest octopus has been reidentified as a distant relative of the nautilus, overturning decades of scientific belief. Published today in Proceedings of the Royal Society B, new imaging techniques reveal that what was once hailed as an ancient octopus was actually a nautiloid that had decomposed before fossilization, deceiving scientists for over 25 years. This discovery reshapes our understanding of octopus evolution and challenges long-held theories about the timeline of cephalopod history.<\/p>\n

The Mysterious Fossil: A Case of Mistaken Identity<\/p>\n

For more than two decades, the 300-million-year-old fossil of Pohlsepia mazonensis held the title of the world\u2019s oldest known octopus. Discovered in Illinois, USA, it featured eight arms, fins, and other characteristics believed to be typical of octopuses. However, the fossil had a peculiar history of uncertainty. Despite its fame and inclusion in the Guinness Book of Records, some scientists questioned the accuracy of its identification. Skepticism grew, but without advanced imaging tools, the true nature of the fossil remained a mystery, until now.<\/p>\n

Recent use of synchrotron imaging, a high-tech method that uses powerful beams of light to uncover hidden details, has exposed crucial new information. The scans revealed microscopic structures inside the fossil<\/a>, including tiny teeth that were once impossible to see with the naked eye. These findings would forever change the narrative.<\/p>\n

Dr. Thomas Clements, the lead author and Lecturer in Invertebrate Zoology at the University of Reading, explained the significance of this breakthrough:<\/p>\n

\u201cIt turns out the world\u2019s most famous octopus fossil was never an octopus at all. It was a nautilus relative that had been decomposing for weeks before it became buried and later preserved in rock, and that decomposition is what made it look so convincingly octopus-like.\u201d<\/p>\n

\"OldestA diagram of the anatomy of the Pohlsepia mazonensis.
Credit: Dr. Thomas Clements, University of Reading<\/p>\n

A Nautilus Relative, Not an Octopus<\/p>\n

The most telling discovery was the presence of a \u201cradula,\u201d a feeding structure found only in molluscs. Unlike octopuses, which have seven or nine teeth in a row, the radula found in the fossil featured 11 tooth-like elements per row, a characteristic of nautiloids. This crucial detail clearly ruled out the possibility of Pohlsepia mazonensis being an octopus and instead confirmed its true identity as a distant relative of the modern nautilus, an ancient shelled mollusk still alive today.<\/p>\n

This identification of a nautiloid relative pushes back the timeline of octopus evolution. Scientists now know that octopuses didn\u2019t emerge until much later, during the Jurassic period, well after the existence of this ancient nautiloid. This discovery redefines our understanding of cephalopod origins and offers crucial insights into the evolutionary path of one of the most intelligent groups of invertebrates on Earth.<\/p>\n

Revolutionizing Our Understanding of Soft Tissue Fossils<\/p>\n

The implications of the study, published in Proceedings of the Royal Society B Biological Sciences<\/a>, go far beyond the reclassification of a single fossil. It provides the oldest known soft tissue evidence of a nautiloid in the fossil record, a significant leap in paleontology. This soft tissue preservation is a rare and valuable glimpse into the past, offering new opportunities to understand the biology and evolution of ancient creatures.<\/p>\n

Dr. Clements highlighted how the discovery was made possible by reexamining the fossil with modern technology: \u201cScientists identified Pohlsepia as an octopus 25 years ago, but using modern techniques showed us what was beneath the surface of the rock, which finally cracked the case. We now have the oldest soft tissue evidence of a nautiloid ever found, and a much clearer picture of when octopuses actually first appeared on Earth.\u201d<\/p>\n

By revisiting a controversial fossil with the tools of today, researchers were able to unravel mysteries that had remained hidden for millions of years. The synchrotron scans revealed a wealth of information, including details about the fossil\u2019s decay process, which contributed to its misleading appearance. This approach highlights how revisiting ancient specimens with modern techniques can yield transformative insights into long-standing scientific debates.<\/p>\n

Implications for the History of Octopus Evolution<\/p>\n

The revelations about Pohlsepia mazonensis provide a more accurate picture of the origins of octopuses. Previously, scientists believed octopuses first appeared hundreds of millions of years ago, during the Paleozoic era. This discovery, however, suggests that octopuses did not evolve until much later, during the Mesozoic era, potentially as late as the Jurassic period.<\/p>\n

\u201cThis study pushes the origin of octopuses further back in time, but not as far as once thought. The evolution of octopuses occurred during the Mesozoic era, not in the Paleozoic as previously believed,\u201d Dr. Clements said. \u201cIt\u2019s amazing to think a row of tiny hidden teeth, hidden in the rock for 300 million years, have fundamentally changed what we know about when and how octopuses evolved.\u201d<\/p>\n

This study not only reshapes the timeline of octopus evolution but also underscores the importance of modern technology in revisiting ancient mysteries. Through the lens of synchrotron imaging, scientists were able to unearth secrets that have lain dormant for millennia.<\/p>\n","protected":false},"excerpt":{"rendered":"A famous fossil once considered the world\u2019s oldest octopus has been reidentified as a distant relative of the…\n","protected":false},"author":2,"featured_media":523502,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[59,90,56,54,55],"class_list":{"0":"post-523501","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-gb","9":"tag-science","10":"tag-uk","11":"tag-united-kingdom","12":"tag-unitedkingdom"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/523501","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=523501"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/523501\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/523502"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=523501"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=523501"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=523501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}