What's the right Dunkleosteus for you?

[andrewsaurus rex]

Gwangi, you make good points.  It would strengthen my case if I, or someone, could propose a reasonable alternate lifestyle for Dunk, other than being a pelagic predator.

I remember reading about a study that demonstrated that Dunk could open its mouth extremely quickly...so quickly that it created a suction force to suck prey into its mouth the way some modern fish do (Groupers I think?).  If this is true, it would be a good trait for an ambush predator to have.

Since bottom dwelling appears to be out of the question, I wonder about Dunk lurking in deep water, where visibility is poor due to low light and perhaps murky conditions.  In a case like that it could perhaps just hover, motionless, relying on poor visibility and perhaps its natural camouflage to obscure it,  waiting for prey to stray too close and then whoosh, suck it into its mouth.

Any evidence Dunk had keen eyesight or was adapted for deep water?

[stargatedalek]

Suction also serves whales, pelicans and whale sharks rather well when charging schools of fish, it's far from something exclusive to ambush predators.

And even if we assume Dunkeosteus was an abnormally slow swimmer, that still doesn't explain it having extremely unusual fins relative to other large fish. Fleshy fins are not exclusive to sharks and ray-finned fish that reach large sizes have heavily altered fins to function more like shark fins do, if not fleshy fins of their own.

Forget needing to move quickly, Dunkeosteus would have significant handicaps to moving in general if it lacked these basic adaptations other large marine animals have. Especially since it was so front heavy.

[Faelrin]

@Loon Okay but now you've gone and made me wish there was a bigger version of that Kaiyodo skull, complete with hinged jaw (unless there is and I forgot about it), like 1/40-1/30 scale. It would make a fantastic display piece (though that said the Kaiyodo one there is still interesting).

[Loon]

@Loon Okay but now you've gone and made me wish there was a bigger version of that Kaiyodo skull, complete with hinged jaw (unless there is and I forgot about it), like 1/40-1/30 scale. It would make a fantastic display piece (though that said the Kaiyodo one there is still interesting).

I imagine very few animals aside from dinosaurs get skull replicas, especially at a larger scale. I guess the only way a larger version would be released would be if Rebor did one like the Carnotaurus, etc. Though, I don't know what size those were.

[andrewsaurus rex]

Stargatedalek you make some good points.  Weight increases much faster than physical dimension ie an animal twice as long weighs 8 times as much simply because its body is 8 times the volume (assuming similar density between the two animals, yadda, yadda).

So I can see Dunk's fins adapting as it got larger to move its much heavier bulk.  But since the head remained pretty much unchanged, I still don't think they'd be the sweeping body changes that make some restorations look like a shark with a Dunkleosteus head stuck on the front.  Afterall, if its larger size and weight were making it difficult to move, you'd think one of the first things to happen would be the head slimming down and becoming lighter.  Since virtually no other fish are armoured, armour can't be that important an adaptation that it would remain unchanged despite significant selective pressures to become faster, or at least be able to move your ever growing bulk.

But I can certainly see Dunk's body and fins becoming more shark like as it evolved ever larger.  So while it may never have had a truly shark like body, it could have been headed in that direction.

[Halichoeres]

Hast thou considered my servant the orca? The tail is oriented horizontally because it's made of mammal vertebrae, but otherwise it's probably a reasonable analog to an arthrodire in terms of swimming performance. It's possible that its jaw morphology wouldn't let it get 'pointier,' but that wouldn't stop it being a powerful swimmer. Shark mouths don't open like whale mouths, because the entire jaw apparatus is slung under the skull by ligaments, and they swing both jaws forward as a unit during a strike. Orcas have their upper jaw fused to the braincase, and so did arthrodires. That alone could make it impossible to change the head shape much without impeding the ability to feed effectively.

Also, armor is widespread in fishes, although, yes, these days it's pretty uncommon in large pelagic ones.

[SidB]

@Halichoeres , though this is hardly a Dunkleosteus comment, since it is your thread, I though it an not inappropriate spot to congratulate you on recently achieving and surpassing the 10,000 post mark. Your contributions have been not only voluminous but also of a consistently high quality. Also, I enjoy both your subtle sense of humor and winsome humanity. Ready for another ten thousand?

[Halichoeres]

S @SidB thank you for the kind words. I never set out to have a superlative number of posts. I just operate on a sort of meta-golden-rule, in that I assume everyone else is treating each other how they'd like to be treated. If someone has put in the effort at a substantive post, perhaps including the minor hassle of hosting and linking images, I generally assume they'd like some acknowledgment of and engagement with their effort. The only way to do that here is with a comment, so I tend to oblige them with one. On the other hand, when people post to their own threads but rarely or never acknowledge others' posts, I infer that they're not interested in comments on their own threads either, and I tend to oblige them with none. So if people keep supporting and replying to each others' posts, I will too.

[SidB]

You are more than welcome, @Halichoeres , and thank you for sharing a bit of your philosophy of involvement, which is both upbuilding, and, at the end of the day, wise, because it actively, by example, promotes  a collective health for the group and the persons in it. In other words, it encourages us to move beyond mere individualism towards becoming persons in community. Again, hope that you can be here for another 10,000 posts (not that you're counting, of course).

[SBell]

Relevant question for this thread--have you seen the pictures of the new PNSO model? There's photos on FB...it looks very fish like if that makes sense.

[Halichoeres]

OK, the PNSO Dunkleosteus:


The good:
• They've done a good job giving it skin. The plates have the same color pattern as the rest of the body, and the small plates at the front of the head have some soft tissue overlying them. They haven't gone too overboard in the texture department, as with their Ophthalmosaurus or CollectA's be-tubercled monster.
• The eyes contain the sclerotic rings, rather than vice versa.
• The tail is biomechanically plausible.
• The fins are generally sharklike, which is good because, like shark fins, placoderm fins were supported by ceratotrichia.

The bad:
• The aspect ratio of the fish is pretty bad. In other words, it's way too sinuous. This is a common malady in PNSO's aquatics. I think they're averse to neutral swimming poses, so in order to make the figure seem more dramatic, they contort it, which requires making some parts of the animal implausibly elongate. The same thing happened with their Eurhinosaurus.
• I don't know the position of Dunk's dorsal fin with certainty (maybe someone does, but if so, I haven't found them saying so). This one seems modeled after Coccosteus, but for a big pelagic animal it would probably have been farther forward. On the plus side, they have given it a plausible height.
• The gill openings are too dorsal. They should be ventro-lateral, behind the lower jaw and perhaps the bottom edge of the suborbital plate. The suborbital probably did not move in the manner depicted.

On the whole, I still think Favorite's version is the most faithful depiction of this animal, but in part that's because overall body shape and biomechanical plausibility are important to me. This one definitely has nicer pajamas, so if you find the harsh offset between the armored and unarmored parts of Favorite's version off-putting, you might prefer the PNSO despite its somewhat eel-y aspect.

Edited to change "infraorbital" to "suborbital," the correct name for the plate beneath the eye. Infraorbitals are the small dermal bones beneath the eyes of actinopterygians, and I must have had them on the brain when I wrote this.

[SBell]

Some of those points I had considered. My takeaway from your opinion is Favorite is better, but the PNSO has some really nice details.
I agree that the finish and skin makes it look really nice, but it's very looooong.
And given the usual prices of PNSO...
Is there an elongated arthrodire that this might better represent?

[Bread]

Thanks for the analysis Halichoeres!

Now, the armored-unarmored transition does bother me a bit on the Favorite model as to why I had an initial debate on getting it. Definitely a positive for PNSO.

[stargatedalek]

So it gets a lot of the details right, but falters on underlying proportions and more foundational anatomy. Sadly kind of a trend for PNSO, especially their aquatics.

[SBell]

So it gets a lot of the details right, but falters on underlying proportions and more foundational anatomy. Sadly kind of a trend for PNSO, especially their aquatics.

It's tougher to swallow, especially given the general prices and difficulty in getting them.

[Flaffy]

Thank you Halichoeres for the analysis!

A bit of a shame that PNSO failed to capture the correct gill placement on their model. Considering the head is the only part of the animal we have preserved, IMO it's of the utmost importance to get everything right about the parts of the organism we do actually know about.

This begs the question as to whether or not these can even be labeled as rigorous scientific reconstructions in the first place. It's certainly a nice figure to look at, there's no doubt about it, probably one of the best Dunkleostues figures on the market; but isn't it disingenuous for PNSO to treat these as scientific reconstructions when even basic anatomy of the genus is not adhered to?

[Gwangi]

Thanks for the breakdown @Halichoeres.

My initial reaction to this Dunk was that it's too elongated, but I do like it otherwise. Having only the Safari Dunk in my collection I might get this one, we'll see.

[Reuben03]

id prefer pointed down pectoral fins, so it can stand up, is that just me?

[Faelrin]

Agreeing with folks around here. It's a shame how close they get, but still miss on key aspects (such as the gill placement). Then add on how pricey they have gotten as well (for me at least anyways). It makes it harder to commit to such a line going forward. I also agree that some of their latest (if not older) figures have not been as rigorous as they should have been. It is also quite strange, that there are things they are very conservative on (like Nanotyrannus, no lipped theropods, etc), but on the other hand they are also willing to make the speculative jump with other things (horizontal tail fluke on Kronosaurus, hooves on the hadrosaurids, etc), that may or may not have supporting research.

I think they should be given the criticism on what they miss the mark on, because how else would they correct going forward (that is assuming they have the intention of doing so)? I think we may have seen this with the various theropods integument. Many of the models from last year and early this year (such as the Tyrannosaurus and the Carnotaurus) had larger scales sculpted on them, but more recent offerings has had much smaller scales, more akin to like we saw on the hadrosaurids.

Focusing on the Dunkleosteus itself, it looks like my haunches about a lot of the issues proved correct (such as the too long body, and possibly the position of the dorsal fin, but thanks for pointing out the shape is not too off), other then the gill placement I was not aware of (though was pointed out in the PNSO 2021 thread as well). In any case thank you @Halichoeres for providing this detailed analysis. At least they do get a lot of things right, and by pointing out what they do get incorrect, can help educate people about what details to pay attention to going forward (or at least hopefully).

Also would the upper and lower jaw articulation be an additional plus as well? I know its something you and others have been wanting to see done on a Dunkleosteus for a long time anyways. Although I can also see that as being a con for those wanting a seamless as possible iteration, which having both upper and lower jaw articulation can detract from.

I also want to point out, that after seeing a top down image of the figure @Faras shared in the PNSO 2021 thread, which I'll share below, the long body doesn't look as bad to me as (or well as long to me) I thought, with my untrained eyes, then when I initially was just going off how it looked in that side profile picture earlier. It almost reminds me of a shark of some kind, and I think the fact the dorsal fin is so far back is possibly making it look longer then it probably is in both top view and side view. But I'm sure @Halichoeres probably knows a lot more to make better judgements then me in this regard so I'll trust that it is too long.



Short of any new Dunkleosteus figures popping up in next year's reveals (like a new iteration from Safari Ltd), I might just plan to get this one, other then the Favorite one as well. It's also been way too long since there's been a fluked tail Dunkleosteus since the release of the Favorite one in 2014 as well, and I think I would like to reward that, as well as some of the other things I like about it (the coloration, top and bottom jaw articulation, skin covering the armor, etc). I also do want to see PNSO branch out into doing more Paleozoic fauna as well, if not fish in general, which is another reason I'd like to pick up the Helicoprion at some point as well.

[SBell]

That top view does make it look pretty cool. My final decision may depend on price