April 27, 2026
Scientists in China have found evidence of giant octopuses that preyed on dinosaurs between 72 and 100 million years ago. They measured an estimated 62 feet and lived in the Late Cretaceous seas. They competed with the ocean apex dinosaurs for food, and even killed and ate them. The mosasaur was likely its most favourite meal. The discovery was made during the re-examination of 15 large fossil jaws from ancient octopus relatives. Scientists from Hokkaido University wrote in the journal Science that their analysis revealed two new species, and one of them grew as large as the sperm whale. That makes them the largest invertebrates to have ever lived on Earth. The species is known as Nanaimoteuthis haggarti, and the clue that gave them away as carnivores was the extensive wear in their jaws. “This extensive wear suggests dynamic crushing of hard skeletons,” the researchers wrote in the study. This showed that the mammoth octopus crushed hard shells and bones, chomping on them with ease.
However, what has intrigued scientists is the evolution of the octopus. These creatures have soft bodies instead of protective shells. Researchers say this led them to become extremely mobile and have great vision. They were also extremely intelligent creatures, which was evident in the way they ate their prey. The team said that they used their long, flexible arms to capture the prey and used their strong beaks to mangle them. Talking about their size, they wrote, “With a calculated total length of (up to) 62 feet (19m), these octopuses may represent the largest invertebrates thus described, rivalling contemporaneous giant marine reptiles.” This makes them almost the same as the sperm whale at 66ft.
The other octopus species discovered is the Nanaimoteuthis jeletzkyi. It grew up to 26 feet in length and was also a predator. “In the largest individuals, the jaws showed extensive wear with once–sharp features in small juveniles becoming blunted and rounded over time,” the scientists said, showing their eating habits. “The long scratches distributed on wide areas of their jaw reflect the dynamic use of the entire jaw for dismantling prey.” Moreover, the jaw edges were blunted on one side, showing they chewed from one side. This indicated “that the earliest octopuses already possessed advanced intelligence”. Scientists said that both these species change a major notion about the marine ecosystem, which was believed to have been primarily linked to large vertebrates such as sharks. However, these giant octopuses and their smaller cousin also played a part in shaping ocean life.
