"Did a 19m Giant Octopus Rule the Cretaceous Seas?"... Apex Predator Theory Raised [Reading Science]

Claim of Strong Carnivory Based on Beak Wear Analysis
Experts: "Coastal Ecology Suggests Limited Competition"

While mosasaurs and sharks have long been considered the apex predators that dominated the Cretaceous seas, a new possibility has emerged suggesting that a colossal octopus, potentially reaching lengths of up to 19 meters, may have been at the very top of the food chain. However, domestic experts have advised caution in interpreting these findings, pointing out ecological limitations.

A research team from Hokkaido University in Japan analyzed the wear patterns on fossilized 'beaks' of ancient octopus relatives and concluded that these creatures may have been strongly carnivorous, capable of crushing hard prey. The study was published in the international journal Science on April 24 (Korean time).

Reference photo to aid understanding of the article. Provided by Pixabay.

The team analyzed 15 existing specimens, along with 12 additional fossils from Late Cretaceous strata, and identified two species: Nanaimoteuthis zelenskyii and Nanaimoteuthis hagartii. These species are estimated to have grown as large as 7 to 19 meters, raising the possibility that they may have been the largest invertebrates ever known, including among modern cephalopods.

"Beak Wear = Carnivory"... Diverging Interpretations

The researchers focused in particular on the wear marks found on the beaks. They observed that the beaks, which were sharp in juveniles, became rounded as the animals grew—interpreting this as the result of repeatedly crushing hard shells or bones. Based on this, the team inferred that these creatures engaged in intense predatory activity.

However, the domestic paleontology community has called for caution regarding some of these interpretations. Lee Yongnam, former professor at the School of Earth and Environmental Sciences at Seoul National University, told the Korea Science & Media Center (SMCK), "The structure referred to as a 'jaw' in the paper is actually the octopus's 'beak,' which is completely different from the jaws of vertebrates."

He also explained that since the fossils were discovered in strata representing shallow coastal environments, it is highly likely that these were coastal-dwelling octopuses, not deep-sea finned octopuses. The beak wear, he interpreted, also reflects an ecology of feeding on hard-shelled crustaceans or mollusks.

Professor Lee further stated, "Because octopuses tend to crawl along the seafloor, their living habitat would have been different from fast-swimming creatures like mosasaurs," adding, "Direct competition with apex predators would have been limited."

This study is significant in that it suggests much larger octopuses may have existed in the Cretaceous seas than those living today, but experts agree that further verification is needed regarding their ecological status.

This content was produced with the assistance of AI translation services.