Massive octopuses, some as long as 62 feet, once roamed the oceans during the time of the dinosaurs. New fossil discoveries suggest that these gigantic invertebrates were top predators in the Cretaceous period.
For years, scientists believed the oceans of the Cretaceous were dominated by huge vertebrate predators, like mosasaurs and plesiosaurs. But the latest research reveals that giant marine predator, nicknamed “krakens,” might have been just as dominant.
Scientists working in Japan and Vancouver Island found fossilized jaws from two extinct octopus species, Nanaimoteuthis jeletzkyiand Nanaimoteuthis haggarti, and these discoveries have changed everything we thought we knew about ancient octopuses.
Giant Octopuses Are Breaking All the Size Records
New research estimates that Nanaimoteuthis haggarti could have grown as long as 62 feet, making it one of the largest invertebrates ever discovered. That’s bigger than a lot of marine reptiles, including the mosasaurs that were around back then. By studying fossilized octopus jaws, scientists were able to estimate the size of these creatures, finding a clear pattern: the larger the jaw, the larger the octopus.
As mentioned in the study, published by Science, the fossils found in rocks dating back 100 to 72 million years ago push back the known history of thise tentacled predator by millions of years. These creatures were not only enormous but also likely fierce predators, hunting hard-shelled animals like mollusks.
“Octopuses are known today as highly intelligent animals, but they are extremely difficult to study in deep time because they lack hard external shells,” said Yasuhiro Iba, a paleontologist from Hokkaido University in Japan. “A major motivation for this study was to reveal this almost invisible history of octopuses.”
Cretaceous Food Chain Reimagined
Before these discoveries, the top predators of the Cretaceous seas were believed to be mostly vertebrates, like large marine reptiles and fish. However, the discovery of these giant arm-footed creatures challenges that view.
The jaws of Nanaimoteuthis species show signs of wear, suggesting they were eating hard-shelled creatures, a sign of powerful and skilled hunters.
“These findings revise the view of the Cretaceous ocean as a world dominated only by large vertebrate predators,” Iba explained. “They show that giant invertebrates — octopuses — also occupied the top of the food web.”
Instead of just seeing giant vertebrates as the rulers of the seas, we now see that giant invertebrates might have been just as important. Animals living alongside these massive ocean creatures may have evolved tougher shells to survive.
The Surprising Skills That Make Them Top Predators
While the size of these octopuses is impressive, what truly sets them apart is their intelligence. The wear marks on their fossilized jaws suggest they were skilled hunters as well. The asymmetrical wear patterns indicate a sophisticated, lateralized hunting method linked to advanced brain function. This type of behavior is also seen in modern octopuses, known for their problem-solving abilities and use of tools.
“Both groups increased swimming performance, body size, and intelligence at the expense of defensive hard parts,” the researchers wrote. “Long after the rise of vertebrate top predators, octopuses evolved body plans capable of rivaling them.”
These findings indicate that ancient octopuses might have been much smarter than we once believed. The wear patterns on their jaws show they were probably dismantling hard-shelled prey, much like modern ones use their tentacles to open jars or escape from enclosures. This intelligence would have made them even more efficient predators in their time.
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