Giant school bus–sized octopuses may have once ruled the oceans

The kraken — a giant, tentacled sea monster that dragged ships into the depths — is a creature of Norwegian myth. But millions of years ago, a similar, real-life animal roamed the oceans, a new study finds.

The new analysis of jaw fossils suggests that as dinosaurs ruled the land, whale-sized octopuses ruled the seas. These super-sized cephalopods would have been the largest marine animals of the Late Cretaceous Period. That’s from about 66 million to 100 million years ago.

Researchers reported their findings April 23 in Science.

Explainer: How a fossil forms

It’s difficult to study fossil octopuses, notes Yasuhiro Iba. He’s a paleontologist at Hokkaido University. That’s in Sapporo, Japan. With soft bodies, these animals tend to break down before becoming fossils. Very few hard parts remain to fossilize. Fortunately, both ancient and modern-day octopuses have a hard, beak-like jaw. This ...