Scientists have identified two species of extinct finned octopuses, which may have reached up to 62 feet (19 meters) long and could be the largest invertebrates ever discovered. Fossil jaws revealed distinctive markings indicating these creatures used their powerful jaws to crush hard-shelled prey. Their size and intelligence suggest they were at the top of the marine food chain during the Cretaceous period. This discovery suggests that scientists need to rethink the oceanic pecking order during this time, which was dominated by large vertebrate predators. The researchers reassessed 15 fossilized octopus jaws previously unearthed in Japan and found 12 new fossil octopus fossils in Japan using state-of-the-art digital fossil-mining technology. They then compared the size, shape and wear marks on these jaws with modern-day Octopuses to reconstruct their body size, feeding behavior and position in the food web.