Nanaimoteuthis, gigantic octopus that hunted in Late Cretaceous oceans (free pdf)

[Ben Creisler]

Ben Creisler

bcre...@gmail.com

A new paper of interest

Free pdf:

Shin Ikegami, Jörg Mutterlose, Kanta Sugiura, Yusuke Takeda, Mehmet Oguz Derin, Aya Kubota, Kazuki Tainaka, Takahiro Harada, Harufumi Nishida and Yasuhiro Iba (2026)
Earliest octopuses were giant top predators in Cretaceous oceans
Science 392(6796): 406-410
DOI:10.1126/science.aea6285
https://www.science.org/doi/10.1126/science.aea6285

Free pdf:
https://www.science.org/doi/epdf/10.1126/science.aea6285


Editor’s summary

The Kraken, the giant cephalopod of legend, was feared by sailors for centuries. Later interpretations suggested that it may have been based on sightings of the giant squid, which can be 10 meters long. Although they lived far too early to have been the source of the legend, Ikegami et al. describe fossil octopods from the late Cretaceous that truly would have fit the description of the monster, reaching up to 19 meters in length. Wear patterns on their jaws suggest that these octopods preyed upon the large reptiles present at the time, including plesiosaurs and mosasaurs. The authors interpret asymmetry in these wear patterns as an indication of corresponding asymmetry in behavior, suggesting complex brain development and, potentially, high intelligence. —Sacha Vignieri

Abstract

Top predators drive changes in ecosystem structure. For the last ~370 million years, large-sized vertebrates have dominated the apex of the marine food chain, while invertebrates have served as smaller prey. Here we describe invertebrate top predators from this “age of vertebrates,” the earliest finned octopuses (Cirrata) from Late Cretaceous sediments (~100 to 72 million years ago), as identified based on huge, exceptionally well-preserved fossil jaws and their wear. This extensive wear suggests dynamic crushing of hard skeletons. Asymmetric wear patterns further indicate lateralized behavior, suggesting advanced intelligence. With a calculated total length of ~7 to 19 meters, these octopuses may represent the largest invertebrates thus described, rivaling contemporaneous giant marine reptiles. Our findings show that powerful jaws, and the loss of superficial skeletons, convergently transformed cephalopods and marine vertebrates into huge, intelligent predators.

***
News:

https://www.science.org/content/article/octopus-krakens-large-semi-trucks-stalked-ancient-seas

https://www.eurekalert.org/news-releases/1125450

https://nautil.us/massive-intelligent-octopuses-once-stalked-the-primordial-oceans-1280161/

https://www.scientificamerican.com/article/kraken-fossils-show-enormous-intelligent-octopuses-were-top-predators-in-cretaceous-seas/

https://www.sciencealert.com/giant-kraken-like-octopuses-once-stalked-their-prey-in-cretaceous-seas

[Tristan Stock]

Extremely cool animal. Congrats to everyone involved in this publication. Definitely not something I think anyone expected.

I know the paper and news articles highlight how this could potentially be a top-order predator, and I have no doubt that it could take large vertebrate prey even at the smallest listed body sizes, but I do have to wonder if the ubiquity of rudist clams and their massive reefs in the late Cretaceous offered a more normal prey basis. Octopod beaks are very specialized for durophagy (as the paper states) and most extant species are using them for that purpose, focusing mainly on bivalve and arthropod prey. Rudists are a major basis for late Cretaceous ecosystems, and several giant marine reptiles seemingly also specialized on bivalves like rudists (Globidensini mosasaurs, protostegid turtles, etc.). A giant octopod could also represent an extension of that ecospace that maybe isn't possible in today's oceans.

--
You received this message because you are subscribed to the Google Groups "Dinosaur Mailing Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to DinosaurMailingG...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAMR9O1KCEoqV5ZXk6H4Qdr7hbLZdJNHLe9RFGg%2By4JffyFr2aA%40mail.gmail.com.

[Thomas Richard Holtz]

Similarly, ammonites were abundant and meaty, and thus suitable prey for giant octopods.

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAAwX0VyrH9CKWmLU%3DAtv4oJ1P%2BKx0ZM7m1zvFKjXjDBkRj2UcA%40mail.gmail.com.

--

Thomas R. Holtz, Jr.
Email: tho...@umd.edu         Phone: 301-405-4084
Principal Lecturer, Vertebrate Paleontology

Office: CHEM 1225B, 8051 Regents Dr., College Park MD 20742

Dept. of Geological, Environmental, and Planetary Sciences, University of Maryland
http://www.geol.umd.edu/~tholtz/

Phone: 301-405-6965
Fax: 301-314-9661              

Faculty Director, Science & Global Change Program, College Park Scholars

Office: Centreville 1216, 4243 Valley Dr., College Park MD 20742
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address: 

                        Thomas R. Holtz, Jr.
                        Department of Geological,

                            Environmental, and Planetary Sciences
                        Building 237, Room 1117

                        8000 Regents Drive
                        University of Maryland
                        College Park, MD 20742-4211 USA

[Tyler Greenfield]

It's a terrible piece of pseudoscience that should be chastised, not congratulated. Let me reframe this as a hypothetical scenario more familiar to dinosaur paleontologists. A paper comes out which estimates a total length of anywhere between 6.6 and 18.6 meters for Tyrannosaurus rex based on a single tooth. The scaling is done based on a purported relationship between tooth size and total length in allosauroids. The authors then claim this as evidence that T. rex was 18.6 meters long and the largest terrestrial predator ever. See how ridiculous this sounds now?

[Tristan Stock]

I agree that the ranges are very unnerving, but people publish very large ranges for marine animals with limited remains all the time. O. megalodon, another large marine predator for which the biting surface (teeth) is all that’s really known, has had published size estimates with similarly huge ranges (10 and 24 meters in the case of stuff like Gottfried et al. 1996). Perucetus also had a huge range in its initial publication that got reduced towards the lower end with future work. I don’t see how this is much different from that, although it is always a bit annoying to really lean on the higher numbers in news articles for the sake of grabbing attention. (Although news story titles like that are pretty widespread throughout the sciences due to how journalism is run these days.)

19 meters feels very outlandish from what my preconceptions about cephalopod size tell me, but even the smallest estimates provided for N. haggarti (7 meters) suggest a very large cephalopod. The beak dimensions are known and, as figured in the paper, exceed that of extant giant squid’s beaks by a large margin. I certainly don’t think it would qualify as truly pseudoscientific, as it implies some level of misleading the public when, ultimately, the big octopus is still a very big octopus. The only way I can see that being the case is if you don’t trust any of the numbers given and somehow push it to well under 6 meters, which is possible, but that’s still a huge beak they have as figured.

Admittedly this is outside of my area of research so maybe I am the one that’s incorrect in my assumptions. I’ll step back and let actual relevant researchers give their two cents. I am very curious what the inevitable follow-ups will look like.

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAL1L4FL1GnT1a6dfFPTSZtfMNKsNwj3qn8Sq-E2eZQYKuYq1pg%40mail.gmail.com.

[Wade Thompson]

Here’s a small correction on O/C.megalodon. While you are right that most of the remains we have of megalodon are teeth, we do have some vertebrae from the giant shark that has allowed us to have a slightly better understanding of what megalodon looked like. Go look up Tyler greenfield’s paper on skeletal remains of odontidae so you can see what I’m talking about.

[Tyler Greenfield]

My counterpoint to that is that the initial paper on Perucetus and the recent ones on "slender" O. megalodon were similarly pseudoscientific (or at least poorly scientific) in their methodlogy. We should not accept this kind of thing just because it is common in the literature.

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAAwX0VwcNWUbsouHLQwVggto%3D1KxO9iY7UQOn%2B8yXyhujOr3pA%40mail.gmail.com.

[Wade Thompson]

I know this is off topic, but I’m curious as to what issues you have with the slender megalodon paper? What about it do you think is bad?

[Gregory Paul]

An interesting item about the original Perucetus paper was that the novel methods used for mass estimation were actually practical -- if done properly. As they were by my co-author Asier L. A problem with the first paper was that it did not follow the standard scientific procedure of cross checking results with an established method, which is of course volumetric modeling. Yet the paper got past the editor/s -- who should have spotted the problem and declined it -- and the reviewers and made it into Nature, where the science news reporters took it seriously. Had the obvious double check been done then the original paper would not have produced such outlandish masses, and it would have been published in a paleo journal without a problem. Or so much attention. 

Of course it is not just the Nature paper that was not duly scientific, so was the Science paper on super duper giant Triassic ichthyosaurs that have never been confirmed by volumetric models even by the authors, such not being possible. Nor have the authors admitted their big boo-boo. So far all my attempts to publish a paper showing why have gone nowhere. Because people who think they know how to do science but don't are reviewing it. 

Likewise, my effort to publish a paper on the actual shape of the blue whale (https://www.biorxiv.org/content/10.1101/2022.08.28.505602v1) -- marine artists all put out different body forms and none are correct -- was turned down by every marine biology journal one way or another. Seems they are about population and behavior studies of whales, not getting the art at museums and popular books the hoypoloi see right. 

Now that I think about it, perhaps I should post by ichthyosaurs paper on BioRxiv.  

GSPaul

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAL1L4FLX-Y7R7qRWv7d%3D3DOSRYZwpKAQLtmbSfwXS8Y9dkrn2g%40mail.gmail.com.

[Darius Nau]

There are certainly big issues with estimates for extinct sharks based
on isolated teeth or vertebrae as well, which warrant taking any such
estimate for an individual specimen with a huge grain of salt. That
being said, at least the size difference between them and extant scaling
analogues that have been used tends to be a lot less than that for N.
haggarti and cirrate octopus species.
The size difference between /Stauroteuthis syrtensis/ and that estimated
for N. haggarti based on it, for example, would be roughly equivalent of
basing a record-sized O. megalodon on a 0.5-1 m long extant analogue.

/Perucetus/, to my mind, suffered from a similar problem to
/Nanaimoteuthis/. It is not that the methods employed are necessarily
unsound in principle, but rather that a vast range was first estimated
(highlighting the huge level of uncertainty and/or different assumptions
that had major effects on the result), only for the conclusion to then
only be based on one extreme of that range (in both cases the upper
one). If we used that same approach on other animals (using tiny
fragments to estimate huge ranges, then picking the upper end and
disregarding the rest), such as giant sauropods or ichthyosaurs, we
would have to be talking about 200+t body masses for some of them.

Another issue with /Nanaimoteuthis/ is that the conclusion that it "had
among the largest body sizes of all organisms in the Cretaceous oceans"
seem to be completely ignoring the aspect of body mass.

Even disregarding the issue of reliability of the upper size estimate,
it seems odd to compare animals of such radically different body shapes
based on total length alone. After all, thanks to its long tentacles,
/Architeuthis/ (which the authors erroneously claim to be the "biggest
invertebrate so far known") can also reach total lengths that would
easily put it among the largest organisms known from Cretaceous oceans,
yet the largest specimens still mass under 300 kg, on the order of 2-4
percent the size of the largest known Cretaceous pliosaurs, mosasaurs
and sharks.

Even if (that is, if we want to favor the upper end of the estimated
mantle length) /Nanaimoteuthis/ really grew a bit larger than the
largest extant cephalopod – which is /Mesonychoteuthis/, not
/Architeuthis/ – it still probably wouldn’t even have come close to
rivalling the mass of the actual largest marine fauna from the Cretaceous.

On 4/23/26 23:38, Tristan Stock wrote:
> I agree that the ranges are very unnerving, but people publish very

> large ranges for marine animals with limited remains all the time. /O.
> megalodon/, another large marine predator for which the biting surface

> (teeth) is all that’s really known, has had published size estimates
> with similarly huge ranges (10 and 24 meters in the case of stuff like

> Gottfried et al. 1996). /Perucetus/ also had a huge range in its initial

> for /Tyrannosaurus rex/ based on a single tooth. The scaling is done

> based on a purported relationship between tooth size and total
> length in allosauroids. The authors then claim this as evidence

> that /T/. /rex /was 18.6 meters long and the largest terrestrial

> predator ever. See how ridiculous this sounds now?
>
> On Thu, Apr 23, 2026 at 12:21 PM Ben Creisler <bcre...@gmail.com
> <mailto:bcre...@gmail.com>> wrote:
>
> Ben Creisler

> bcre...@gmail.com <mailto:bcre...@gmail.com>

>
> A new paper of interest
>
> Free pdf:
>
> Shin Ikegami, Jörg Mutterlose, Kanta Sugiura, Yusuke Takeda,
> Mehmet Oguz Derin, Aya Kubota, Kazuki Tainaka, Takahiro Harada,
> Harufumi Nishida and Yasuhiro Iba (2026)
> Earliest octopuses were giant top predators in Cretaceous oceans
> Science 392(6796): 406-410
> DOI:10.1126/science.aea6285

> https://www.science.org/doi/10.1126/science.aea6285 <https://
> www.science.org/doi/10.1126/science.aea6285>
>
> Free pdf:
> https://www.science.org/doi/epdf/10.1126/science.aea6285

> semi-trucks-stalked-ancient-seas <https://www.science.org/
> content/article/octopus-krakens-large-semi-trucks-stalked-
> ancient-seas>
>
> https://www.eurekalert.org/news-releases/1125450 <https://
> www.eurekalert.org/news-releases/1125450>
>
> https://nautil.us/massive-intelligent-octopuses-once-stalked-
> the-primordial-oceans-1280161/ <https://nautil.us/massive-
> intelligent-octopuses-once-stalked-the-primordial-oceans-1280161/>
>
> https://www.scientificamerican.com/article/kraken-fossils-show-
> enormous-intelligent-octopuses-were-top-predators-in-cretaceous-
> seas/ <https://www.scientificamerican.com/article/kraken-
> fossils-show-enormous-intelligent-octopuses-were-top-predators-
> in-cretaceous-seas/>
>
> https://www.sciencealert.com/giant-kraken-like-octopuses-once-
> stalked-their-prey-in-cretaceous-seas <https://
> www.sciencealert.com/giant-kraken-like-octopuses-once-stalked-
> their-prey-in-cretaceous-seas>

>
> --
> You received this message because you are subscribed to the
> Google Groups "Dinosaur Mailing Group" group.
> To unsubscribe from this group and stop receiving emails from
> it, send an email to
> DinosaurMailingG...@googlegroups.com

> <mailto:DinosaurMailingG...@googlegroups.com>.

> To view this discussion visit https://groups.google.com/d/msgid/
> DinosaurMailingGroup/

> CAMR9O1KCEoqV5ZXk6H4Qdr7hbLZdJNHLe9RFGg%2By4JffyFr2aA%40mail.gmail.com <https://groups.google.com/d/msgid/DinosaurMailingGroup/CAMR9O1KCEoqV5ZXk6H4Qdr7hbLZdJNHLe9RFGg%2By4JffyFr2aA%40mail.gmail.com?utm_medium=email&utm_source=footer>.

>
> --
> You received this message because you are subscribed to the Google
> Groups "Dinosaur Mailing Group" group.
> To unsubscribe from this group and stop receiving emails from it,
> send an email to DinosaurMailingG...@googlegroups.com

> <mailto:DinosaurMailingG...@googlegroups.com>.

> To view this discussion visit https://groups.google.com/d/msgid/

> DinosaurMailingGroup/CAL1L4FL1GnT1a6dfFPTSZtfMNKsNwj3qn8Sq-
> E2eZQYKuYq1pg%40mail.gmail.com <https://groups.google.com/d/msgid/
> DinosaurMailingGroup/CAL1L4FL1GnT1a6dfFPTSZtfMNKsNwj3qn8Sq-
> E2eZQYKuYq1pg%40mail.gmail.com?utm_medium=email&utm_source=footer>.

>
> --
> You received this message because you are subscribed to the Google
> Groups "Dinosaur Mailing Group" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to DinosaurMailingG...@googlegroups.com

> <mailto:DinosaurMailingG...@googlegroups.com>.

> To view this discussion visit https://groups.google.com/d/msgid/
> DinosaurMailingGroup/

> CAAwX0VwcNWUbsouHLQwVggto%3D1KxO9iY7UQOn%2B8yXyhujOr3pA%40mail.gmail.com
> <https://groups.google.com/d/msgid/DinosaurMailingGroup/
> CAAwX0VwcNWUbsouHLQwVggto%3D1KxO9iY7UQOn%2B8yXyhujOr3pA%40mail.gmail.com?utm_medium=email&utm_source=footer>.


--
Darius Nau

Department for Paleontology, Bonn Institute of Organismic Biology
(BIOB), University of Bonn

[Mike Habib]

The authors also support their suggestion of macrocarnivory with beak wear characteristics. That might be up to question, too, of course. That said, even if we take the minimum of their size range estimates, that’s still plenty large enough to be a macro carnivore of subadult marine reptiles (aka a true apex predator). So the overall ecological conclusion may still be sound, even if the gigantism has been overplayed.

Cheers,

—Mike H.

On Apr 23, 2026, at 12:17 PM, Tristan Stock <tristan....@gmail.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAAwX0VyrH9CKWmLU%3DAtv4oJ1P%2BKx0ZM7m1zvFKjXjDBkRj2UcA%40mail.gmail.com.

[Dawid Mazurek]

The ecological interpretation is not sound at all. Durophagous top predator? What that even means? Are there any marks on reptile bones? Durophage would hunt inoceramids.

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/FF449CBD-193B-48EC-99E4-33AA07FE0761%40gmail.com.

[Thomas Richard Holtz]

"Durophage would hunt inoceramids." True. And rudists. And (likely most importantly, because they are numerically far more abundant) ammonoids.

To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAGeKeKux0Z%2BE6zSGcKJPPTs_q2RH3rvrPkU5%3DtLYSQs23iYoqw%40mail.gmail.com.