Apr 23, 2026 09:00 PM
https://www.eurekalert.org/news-releases/1125450
INTRO: Today’s octopuses are intelligent, remarkably flexible animals that lurk in reefs, hide in crevices, or drift through the deep sea. But new research suggests that their earliest relatives may have played a far more predatory role in ocean ecosystems. A study led by researchers at Hokkaido University has found that the earliest known octopuses were giant predators that hunted at the very top of the food web, alongside large marine vertebrates. The study was published in Science on 23 April 2026.
Octopuses are soft-bodied animals and so they rarely fossilize well. This makes their evolutionary history especially difficult to trace compared with animals that leave behind bones or shells. In this study, the researchers used fossil jaws of early octopuses, a feeding organ with a high fossilization potential, to reconstruct their hidden history.
Using high-resolution grinding tomography and an artificial intelligence model, they found fossil jaws hidden inside rock samples from the Late Cretaceous period, spanning 100 to 72 million years ago. These fossils, found in Japan and Vancouver Island, had been well preserved in calm seafloor sediments, retaining fine wear marks that revealed how these animals fed.
The fossils belonged to a group of extinct finned octopuses, known as Cirrata. By analyzing the size, shape, and wear patterns of the jaws, the team concluded that these animals were active predators that likely crushed hard prey with powerful bites.
“Our findings suggest that the earliest octopuses were gigantic predators that occupied the top of the marine food chain in the Cretaceous,” says Professor Yasuhiro Iba of Hokkaido University. “Based on exceptionally well-preserved fossil jaws, we show that these animals reached total lengths of up to nearly 20 meters, which may have surpassed the size of large marine reptiles of the same age.”
“The most surprising finding perhaps was the extent of wear on the jaws,” says Iba. The fossil jaws showed extensive chipping, scratching, cracking, and polishing, all signs of a strong biting force. “In well-grown specimens, up to 10% of the jaw tip relative to the total jaw length had been worn away, which is larger than that seen in modern cephalopods that feed on hard-shelled prey. This indicates repeated, forceful interactions with their prey, revealing an unexpectedly aggressive feeding strategy.” These findings suggest that these ancient octopuses were powerful and active hunters that consumed abundant prey.
The discovery changes what scientists thought about the early history of octopuses. The new fossils extend the earliest known record of finned octopuses by around 15 million years and the broader octopus record by around 5 million years, placing them as far back as about 100 million years ago... (MORE - no ads)
INTRO: Today’s octopuses are intelligent, remarkably flexible animals that lurk in reefs, hide in crevices, or drift through the deep sea. But new research suggests that their earliest relatives may have played a far more predatory role in ocean ecosystems. A study led by researchers at Hokkaido University has found that the earliest known octopuses were giant predators that hunted at the very top of the food web, alongside large marine vertebrates. The study was published in Science on 23 April 2026.
Octopuses are soft-bodied animals and so they rarely fossilize well. This makes their evolutionary history especially difficult to trace compared with animals that leave behind bones or shells. In this study, the researchers used fossil jaws of early octopuses, a feeding organ with a high fossilization potential, to reconstruct their hidden history.
Using high-resolution grinding tomography and an artificial intelligence model, they found fossil jaws hidden inside rock samples from the Late Cretaceous period, spanning 100 to 72 million years ago. These fossils, found in Japan and Vancouver Island, had been well preserved in calm seafloor sediments, retaining fine wear marks that revealed how these animals fed.
The fossils belonged to a group of extinct finned octopuses, known as Cirrata. By analyzing the size, shape, and wear patterns of the jaws, the team concluded that these animals were active predators that likely crushed hard prey with powerful bites.
“Our findings suggest that the earliest octopuses were gigantic predators that occupied the top of the marine food chain in the Cretaceous,” says Professor Yasuhiro Iba of Hokkaido University. “Based on exceptionally well-preserved fossil jaws, we show that these animals reached total lengths of up to nearly 20 meters, which may have surpassed the size of large marine reptiles of the same age.”
“The most surprising finding perhaps was the extent of wear on the jaws,” says Iba. The fossil jaws showed extensive chipping, scratching, cracking, and polishing, all signs of a strong biting force. “In well-grown specimens, up to 10% of the jaw tip relative to the total jaw length had been worn away, which is larger than that seen in modern cephalopods that feed on hard-shelled prey. This indicates repeated, forceful interactions with their prey, revealing an unexpectedly aggressive feeding strategy.” These findings suggest that these ancient octopuses were powerful and active hunters that consumed abundant prey.
The discovery changes what scientists thought about the early history of octopuses. The new fossils extend the earliest known record of finned octopuses by around 15 million years and the broader octopus record by around 5 million years, placing them as far back as about 100 million years ago... (MORE - no ads)
