'Kraken' May Have Been King of Cretaceous Seas

Creatures that strongly resemble legends of the Kraken may have been the kings of Cretaceous seas. A study in Science finds that ancient octopus species, inferred from massive fossil beaks from 72 to 100 million years old, may have stretched as long as 62 feet, longer than a bowling lane—putting them in the same weight class as the era's top marine reptiles and possibly turning those mosasaurs and plesiosaurs into prey. Distinct grinding and chipping on the beaks suggests they routinely crushed bones and shells rather than just soft-bodied meals.

• "Our study shows that these were not simply large versions of modern octopuses," says lead author Yasuhuro Iba, a palaeontologist at Hokkaido University. "They were giant predators at the very top of the Cretaceous marine food web. This changes the view that Cretaceous seas were dominated only by large vertebrate predators."

Researchers reexamined 15 beaks previously misidentified as vampire squid. They used a technique called "digital fossil mining" to find 12 more hidden in rocks, the AP reports. Researchers determined they belonged to a group called Nanaimoteuthis. One species, N. haggarti, had a beak larger than that of today's giant squid, previously considered the biggest invertebrate. Using modern octopuses as a guide, scientists estimate N. haggarti's length at 23 to 62 feet, with the largest ones much bigger than any modern octopus species.

Wear patterns show the animals likely grabbed prey with long arms and used powerful jaws to crack through hard parts while uneven wear hints at "handedness," or favored arms, much like modern octopuses. The asymmetry suggests "complex brain development and, potentially, high intelligence," per Science.

• "To see a beak this size is quite amazing, to be honest. It was a massive animal," Thomas Clements, a paleobiologist at the University of Reading, tells the Guardian. "I certainly wouldn't have wanted to go swimming in the ancient oceans if these things were swimming around." He adds: "Whenever you see artistic reconstructions, it's always a vertebrate eating a cephalopod. It is quite nice to imagine an octopus eating a large vertebrate for once. As a cephalopod researcher, I'm very excited to see invertebrates that may have rivalled vertebrates."