Today's octopuses are intelligent, remarkably flexible animals that lurk in reefs, hide in crevices, or drift through the deep sea. But new research suggests that their earliest relatives may have played a far more predatory role in ocean ecosystems. A study led by researchers at Hokkaido University has found that the earliest known octopuses were giant predators that hunted at the very top of the food web, alongside large marine vertebrates. The study is published in Science.