What the study found
The study identifies the earliest finned octopuses, a group called Cirrata, as invertebrate top predators from Late Cretaceous oceans. The authors report that these animals may have reached about 7 to 19 meters in total length and could have rivaled giant marine reptiles in size.
Why the authors say this matters
The authors say their findings show that powerful jaws, along with the loss of superficial skeletons, independently helped cephalopods and marine vertebrates become huge, intelligent predators. The study suggests that these octopuses were part of the marine apex food chain during a period often described as the age of vertebrates.
What the researchers tested
The researchers examined exceptionally well-preserved fossil jaws from Late Cretaceous sediments, dated to about 100 to 72 million years ago. They used the jaws' size and wear patterns to identify the animals and to infer how they may have fed and behaved.
What worked and what didn't
The fossil jaws showed extensive wear, which the authors interpret as evidence of dynamic crushing of hard skeletons. Asymmetric wear patterns were also observed, and the authors say these suggest lateralized behavior, which they associate with advanced intelligence.
What to keep in mind
The summary does not describe limitations beyond the fact that the conclusions are based on fossil jaws and their wear. The study's size estimate and behavioral interpretations are inferred from preserved remains rather than directly observed.
Key points
- The earliest finned octopuses are described as Late Cretaceous invertebrate top predators.
- Exceptionally preserved fossil jaws were used to identify the animals.
- Wear on the jaws suggests crushing of hard-shelled prey.
- Asymmetric wear patterns are interpreted as possible evidence of lateralized behavior.
- The octopuses are estimated to have been about 7 to 19 meters long.
Disclosure
- Research title:
- Earliest octopuses were large Cretaceous top predators
- Authors:
- Shin Ikegami, J. Mutterlose, Kanta Sugiura, Yusuke Takeda, Mehmet Oguz Derin, Aya Kubota, Kazuki Tainaka, Takahiro Harada, Harufumi Nishida, Yasuhiro Iba
- Institutions:
- Chuo University, DMG Mori (Japan), DMG Mori (Japan), Hokkaido University, Hokkaido University, Hokkaido University, Japan Synchrotron Radiation Research Institute, Niigata University, Osaka Metropolitan University, Ruhr University Bochum, Tokyo Metropolitan University
- Publication date:
- 2026-04-23
- OpenAlex record:
- View
- Image credit:
- Photo by ArtisticOperations on Pixabay · Pixabay License
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