Giant octopuses may have ruled the ancient oceans 100 million years ago, when dinosaurs roamed, according to new research.
Some of the earliest octopuses are believed to have been powerful predators equipped with strong arms for grabbing prey and beak-like jaws for munching on the shells and bones of other animals.
A new study of some remarkably well preserved jaws suggest they reached up to 19 metres, potentially making them the largest invertebrates ever known to scientists.
For decades, palaeontologists believed that the largest ocean predators were vertebrates with backbones such as fish and reptiles while invertebrates like octopuses and squid played supporting roles.
New research by scientists from Hokkaido University in Japan challenges the picture scientists had of ancient octopuses.
