Was a Giant Octopus the Top Predator of the Dinosaur Age?
New fossil evidence suggests Nanaimoteuthis could have rivaled the prehistoric ocean’s most fearsome marine reptiles.
The Guinness World Records entry was confident: the world’s oldest known octopus, was 300 million years old, and preserved in ancient stone. Scientists had studied it, named it, and built a small corner of the fossil record around it. Then, in early April 2026, a new analysis was published, and it turns out the creature we thought was an octopus was not one at all. It had never been. It was a shelled, slow nautilus relative, about as far from a kraken as you can get while still technically being a cephalopod.¹
Then, 14 days later, Science published a paper that went in the exact opposite direction. Scientists analyzing the fossil record using new methods had found evidence of an even larger and older Octopus. It is the kind of reversal that makes you wonder what else we have been confidently wrong about.
Picture the Cretaceous ocean, roughly 100 million years ago. Dinosaurs, including perhaps the largest ever; long-necked titanosaur sauropods and giant carnivores that hunted them like giganotosaurus, own the land. Airplane-sized flying reptiles known as pterosaurs like Quetzalcoatlus rule the skies. Underwater, the story paleontology has always told features a different cast: mosasaurs, long-bodied marine reptiles with jaws straight out of a nightmare; plesiosaurs, the long-necked ones that look like someone attached a snake to a barrel; and sharks, because there are always sharks. It feels like a complete ecosystem. Teachers teach it. Museums model it. Kids memorize it.
What that story was missing, according to a team led by Hokkaido University paleontologist Yasuhiro Iba, was an octopus the size of a school bus.
Possibly several of them.
The species, named Nanaimoteuthis, is based on 27 jaw specimens pulled from sites in Japan and Canada’s Vancouver Island. They suggest animals that may have reached lengths of 23 to 62 feet, among the earliest finned octopuses ever documented. These animals lived in the same waters as the mosasaurs and plesiosaurs that have dominated natural history exhibits.²
“We were surprised,” Dr. Iba told CNN. “The fossil record of octopuses is extremely limited, so finding animals this large and ecologically important in the Cretaceous ocean was beyond our expectations.”³
Here is why the fossil record is so thin, and why that matters: octopuses are designed to disappear. Their bodies are soft tissue. It breaks down quickly, long before mineralization can do its work. The only parts of an octopus with any realistic chance of becoming fossilized are the jaws that are two small, curved structures made of chitin. They are tough enough to survive but easy to miss. One small beak in a rock, the size of a dining table, is not something you often stumble across.That is why 12 of those 27 specimens were not found by anyone looking for them. They were found by a machine.
Iba’s team developed a technique they call digital fossil mining, a combination of grinding tomography, which scans rock in precise cross-sections, and an AI model trained to recognize jaw structures in the resulting data. They ran it on sedimentary rock that had already been collected, cataloged, and stored. The fossils were there the whole time. They just needed the right tool to see them. ²˒³
“Our goal is to reveal the hidden players of ancient ecosystems,” Dr. Iba said, “and build a much more complete picture of how past ecosystems really worked.”³
That ambition has implications beyond this one study. Grinding tomography does not care whether the creature inside the rock was an octopus or something else entirely. Apply it systematically to existing collections, and the soft-body fossil record stops being a dead end. Creatures that seemed to have vanished without a trace may simply be sitting in storage, waiting for the right scan that lets us notice them.
So, were these animals apex predators? Were they genuinely competing with mosasaurs for the top of the food chain, or were they 60-foot opportunists eating fish and avoiding sea reptiles?
The wear patterns on the jaws, chips, scratches, and rounded edges point to repeated crushing of hard materials such as shells and bones. University of Oxford zoologist Dr. Tim Coulson told CNN that their size alone strengthens the argument. “Their size suggests they were an apex predator, sat at the top of the food chain.”³
University of Bristol paleontologist Dr. Jakob Vinther offers a more measured view. He called the find “a pretty amazing find” and then asked the practical question the paper cannot fully answer: how long would it take a 60-foot octopus to break down and swallow something the size of a plesiosaur? Large prey is metabolically expensive. Nanaimoteuthi could have met its energy needs entirely on fish and mollusks, using those powerful jaws on prey that was impressive but not headline-grabbing. The wear patterns confirm crushing. They do not confirm what was being crushed, or how large it was.³
What Dr. Vinther does not dispute, and what nobody disputes, is that these were formidable and ecologically significant animals. “Probably a significant predator toward certain larger-bodied prey,” he said. The exact definition of apex becomes a semantic argument. The presence of something this large sharing those waters with everything we thought we understood about the Cretaceous sea is not.
What is striking is how quickly the picture shifted. The oldest octopus record disappeared on April 9. The Nanaimoteuthis paper was published on April 23. In two weeks, the octopus’s place in prehistory first contracted and then expanded dramatically, and the field moved on before most people noticed the shift.The evolving narrative is not a flaw in the science. Rather, it is science working.
The fossil record for soft-bodied creatures has always been a story told through gaps and absences, through organisms that left almost no trace and therefore did not make it into the narrative. The Cretaceous Ocean was home to mosasaurs, plesiosaurs, and sharks. Also, apparently, something enormous with eight arms and jaws strong enough to crush bone, hunting in the same waters, probably for millions of years, without us knowing it was there.
“It’s a big old planet,” paleontologist Dr. Neil Landman of the American Museum of Natural History told The Seattle Times. “So, we have lots to look at to piece together the marine ecosystem through time.”⁴
The kraken, it turns out, was not a myth. It was just waiting in the rock for someone to build the right machine that allowed us to see evidence of their existence.
Sources:
¹ “Scientists say the world’s oldest octopus fossil isn’t an octopus after all.” The Seattle Times, April 9, 2026.
https://www.seattletimes.com/nation-world/scientists-say-the-worlds-oldest-octopus-fossil-isnt-an-octopus-after-all/
² Iba, Yasuhiro et al. “Giant finned octopus Nanaimoteuthis as a Cretaceous apex predator.” Science, April 23, 2026.
https://www.science.org/doi/10.1126/science.aea6285
³ Guy, Jack. “Giant, 60-foot octopuses were apex predators 100 million years ago, fossil discovery shows.” CNN, April 23, 2026.
https://www.cnn.com/2026/04/23/science/giant-octopus-apex-predator-scn/index.html
⁴ “A massive kraken-like octopus may have prowled the seas during the age of dinosaurs.” The Seattle Times, April 23, 2026.
https://www.seattletimes.com/seattle-news/science/a-massive-kraken-like-octopus-may-have-prowled-the-seas-during-the-age-of-dinosaurs/
