Giant Octopuses May Have Ruled the Oceans 100 Million Years Ago Fossilized jaws of ancient octopuses, discovered in Japan and Vancouver Island, have revealed that these creatures may have been apex predators in the oceans 100 million years ago. A study led by researchers at Hokkaido University, published in Science, challenges previous assumptions about the role of invertebrates in marine ecosystems, suggesting that early octopuses occupied the top of the food web alongside large marine vertebrates. The findings, based on advanced imaging and artificial intelligence analysis, indicate that these ancient octopuses were not merely elusive, soft-bodied animals but powerful hunters capable of crushing hard prey with immense force. The study focused on fossilized jaws from the Late Cretaceous period, spanning 100 to 72 million years ago. These fossils, preserved in calm seafloor sediments, retained fine wear patterns that provided insights into the feeding behavior of these extinct creatures. The researchers used high-resolution grinding tomography and a zero-shot learning AI model to digitally mine the fossils, revealing intricate details of their structure. The jaws belonged to a group of extinct finned octopuses known as Cirrata, which were likely active predators. The analysis of jaw size, shape, and wear patterns suggested that these animals could have grown to nearly 20 meters in length, surpassing the size of contemporary marine reptiles. Professor Yasuhiro Iba of Hokkaido University emphasized the significance of the findings, noting that the fossilized jaws showed extensive damage, including chipping, scratching, cracking, and polishing. These signs of wear indicated a strong biting force, with up to 10% of the jaw tip relative to the total length worn away in well-developed specimens.#science #japan #vancouver_island #hokkaido_university #cirrata