New analyses of fossilized jaws reveal that massive, kraken-like octopuses once hunted alongside other marine predators. They boasted eight arms and long bodies that extended more than 60 feet, rivaling other carnivorous marine reptiles.

According to CNN, Japanese researchers used recently discovered fossils to compare jaw sizes with modern species and found that these ancient cephalopods reached lengths of 23 to 62 feet, with the largest specimens far exceeding any octopus alive today.

The ancient cephalopod, Nanaimoteuthis haggarti, appears to have been an apex predator that rivaled mosasaurs to rule prehistoric seas.