kraken-like octopus – Fossilized jawbones from Nanaimoteuthis haggarti and related specimens point to massive Cretaceous cephalopods—among the largest invertebrates ever—suggesting giant octopuses helped shape the era’s ocean food web dominated by predators once thought to be verte
For decades. the story of the Cretaceous ocean has leaned heavily on vertebrate hunters—creatures like plesiosaurs and mosasaurs—sweeping through the seas at the top of the food chain. But fossil jawbones recently uncovered in Japan and Canada are forcing a rewrite of that image. with evidence pointing to a kraken-like octopus that may have been one of the biggest marine animals of its time.
The breakthrough centers on Nanaimoteuthis haggarti, a massive, kraken-like cephalopod said to have roamed Earth about 72 million years ago. A study published in the journal Science describes the findings and argues that these enormous cephalopods would have ranked among the largest marine creatures of the Cretaceous Period and could have been the largest invertebrates ever.
Study co-author Yasuhiro Iba, a paleontologist at Hokkaido University in Japan, said the work revises the assumption that Cretaceous oceans were dominated only by large vertebrate predators. “They show that giant invertebrates – octopuses – also occupied the top of the food web,” he said.
The fossil record is unusually specific for an animal this big. Researchers working in Japan’s Yezo Group—a massive Late Cretaceous geological formation on Hokkaido Island—and the Nanaimo Group on Canada’s Vancouver Island discovered exceptionally large fossil jaws. The jaws appear to belong to organisms resembling octopuses. but their exact classification. size in life. and potential ecological role remain unsettled.
The team reported finding 12 additional fossil jaws from rocks in Japan, then examining 15 previously found fossil jaws. From those remains, the creatures were divided into two species—N. Jeletzkyi and N. Haggarti—based on size and form.
Size is where the controversy gets teeth. The study calculated that N. Jeletzkyi reached lengths between 10 and 26 feet, based on its largest jaw. For N. Haggarti, newly discovered jaw material was used to estimate a range of 23 to 62 feet. Those figures suggest N. Haggarti may be the largest invertebrate ever discovered.
The implications don’t stop at the measurements. The finding might indicate prehistoric marine ecosystems had a wider cast of predators and a more complex web of life than previously imagined—an ocean where giant octopuses weren’t side characters, but players at the top.
Still, the details left open are part of what makes the discovery feel raw and unresolved. While the jaws point strongly toward octopus-like animals. researchers say their exact classification. size in life. and ecological role remain a mystery. What’s clear is the direction the evidence points: the Cretaceous sea may have been more crowded with top-tier invertebrate predators than the previous version of the story allowed.
Nanaimoteuthis haggarti kraken-like octopus Cretaceous Period fossil jaws Science journal Yasuhiro Iba Hokkaido University Yezo Group Nanaimo Group marine predators invertebrate food web