An octopus species that lived about 80 million years ago had a body length of up to 19 meters and was likely the top predator in the oceans, researchers said.<\/p>\n
The research team, led by Yasuhiro Iba, an associate professor of paleontology with Hokkaido University, scrutinized 27 fossil specimens found in Japan and Canada dating back to the Late Cretaceous Period (100 million to 72 million years ago).<\/p>\n
They focused mainly on octopus beaks, which are hard enough to be well-preserved in fossil form.<\/p>\n
Deploying a digital fossil-mining method, they used an artificial intelligence system to locate the fossils contained in rocks. They estimated the body dimensions of the octopuses based on the beak sizes.<\/p>\n
The species that was up to 19 meters in length lived between 86 million and 72 million years ago and may have been bigger than present-day giant squids, the researchers said.<\/p>\n
The many scratches and chips on the fossil beaks indicate the Cretaceous octopuses had a very strong biting force and likely fed on hard-shelled prey, such as shellfish and ammonites, along with fish.<\/p>\n
Large fish and other vertebrates have long been considered at the top of the food chain in marine ecosystems over the past 370 million years.<\/p>\n
But the latest finding shows that invertebrate octopuses had evolved into some of the biggest carnivores in the Cretaceous oceans, the researchers said.<\/p>\n