Ancient Giant

At the time of the dinosaurs, the oceans were filled with lots of big, scary creatures. The biggest and scariest might have been some king-sized ancestors of the modern octopus. Some recent research says these monsters could have been as long as a big-rig truck. And they would have been smart—critters you wouldn’t want to see in the flesh.

Scientists looked at the fossilized jawbones of 15 specimens that were already known. And they used a sophisticated imaging technique plus AI to scan a dozen others that hadn’t been recognized as octopus relatives. All of the fossils were found in Japan or on Canada’s Pacific coast. The octopuses lived between 72 million and 100 million years ago.

To determine the size of the creatures, the scientists compared the jawbones to those of modern octopuses. They found that the old guys comprised two species. The largest of them could have reached more than 60 feet long.

The scientists also found that most of the jawbones were chipped and eroded—they’d lost up to a tenth of their original volume. That means the creatures used their jaws to crack the shells and bones of lots of smaller prey.

Many of the jaws were eroded more on one side than the other. That suggests the octopuses preferred to use one side of their body more than the other—just as people prefer one hand over the other. That’s considered a sign of intelligence. So these smart, giant creatures could have been the top ocean predators in the age of the dinosaurs.