Giant octopuses may have ruled the ancient oceans 100 million years ago, when dinosaurs roamed, according to new research.
Some of the earliest octopuses are believed to have been powerful predators, possessing strong arms for grabbing prey and beak-like jaws for chewing the carapace and bones of other animals.
A new study of some remarkably well-preserved jaws suggests they could have been up to 19 meters long, potentially making them the largest invertebrates known to scientists yet.
For decades, paleontologists thought the largest ocean predators were backbone vertebrates like fish and reptiles, with invertebrates like octopuses and squid playing supporting roles.
A giant Pacific octopus meets a diver at the bottom of the ocean [Getty Images]
New research from scientists at Japan’s Hokkaido University challenges scientists’ beliefs about ancient octopuses.
Their analysis of fossilized jaws suggests that giant octopuses glided through the ocean and had the ability to chew the hard shells and bones of large fish and marine reptiles.
Research estimates that its body length is about 1.5 to 4.5 meters, and if the long arms are included, the total length is about 7 to 19 meters.
Even at the lower end of this range, the animal would have been massive by today’s standards.
Another striking feature is that the wear on the fossilized lower jaw is uneven from left to right, suggesting the animal may have favored one side when eating.
In living animals, a preference for one side of the body over the other is associated with higher brain function.
Octopuses are known for their extraordinary intelligence and masters of disguise [Getty Images]
Modern octopuses are known for their intelligence, problem-solving abilities and complex hunting strategies.
The giant Pacific octopus is the largest living species today, with a wingspan of more than 5.5 meters.
Video footage shows the animals battling the shark, which is more than a meter long.
Christian Kluge, a paleontologist at the University of Zurich who reviewed the study, said: “With their tentacles and suction cups, they could perfectly grab an animal like this and be unable to escape.”
However, many questions remain. Scientists can only guess at the animals’ exact shape, the size of their fins, or how fast they swim.
No fossils containing stomach contents have been found that directly prove what they ate.
Dr Nick Longridge, a paleontologist at the University of Bath, said his hunch was that they mainly preyed on ammonites.
However, like modern octopuses, they were opportunistic and voracious predators who would not give up other prey if given the chance.
“It’s going to take a while for us to figure this out,” he said. “It’s a bit of a mystery.”
For now, the fossils offer a glimpse of a deep-sea giant that may have roamed the ancient oceans, possessing a broken jaw, powerful arms and a brain that may have helped it compete with other apex predators.
The study was published in the journal Science.