Big yikes: researchers use Papo to estimate body mass

[Halichoeres]

Lots of researchers focus on body mass as a trait in evolutionary analyses, because it can correlate in interesting ways with things like latitude, trophic level, and the like. In this study, rather than go to the trouble of building on the framework of a skeleton, they scanned figurines of "some of the most recent and scientifically accurate palaeoreconstructions," for example:


Safari Coelophysis. This one might actually be defensible, since the figure is pretty well-proportioned.


Papo Allosaurus. In many ways an impressive sculpt, but absolutely unusable in deriving any meaningful data. A moment's glance at the skeletal diagram shows what a ridiculous choice this is.

Others in the data set:
Papo Ceratosaurus
Safari Dilophosaurus (2020)
Safari Carnegie Giganotosaurus
Rebor King Tyrannosaurus, one of the worst offenders
CollectA Carnotaurus
CollectA Baryonyx

I think this demonstrates a couple of things.
1. Just because something is peer-reviewed doesn't make it magically true. Reviewers are also people who overlook things and sometimes overestimate their own qualifications to evaluate things.
2. Paleontologists don't always care about the things you might think they would care about. To some, like stratigraphers, organismal remains are little more than useful clues to the age of things. Even to the ones that care deeply about their specimens as living organisms, they might not know very much about what they looked like in life because they're hyper-focused on jaw mechanics, or ecological interactions, or biogeography. The number of paleontologists who spend a lot of time thinking about life reconstructions is really pretty small.

Open access, because of course this would be. https://link.springer.com/article/10.1007/s41513-021-00172-1

[suspsy]

I am . . . absolutely appalled, both by the fact that someone actually wrote this and that someone else actually peer reviewed it. By all rights, they should be laughingstocks.

[Reuben03]

bloody hell I feel like becoming a creationist now.

I think i just threw up in my mouth.

[CityRaptor]

Just wait for REBOR'S eventual reaction to this.

Of course the whole thing is just a modern update of an old method using toy figures:
https://www.fossilhunters.xyz/defining-dinosaurs/dinosaur-models-and-the-estimation-of-dinosaur-weights.html

[Dusty Wren]

This is...surreal. I am totally baffled by this.

My favorite part is their description of how they controlled for the accuracy of the figures:

First of all, approximations to the skull-size/body-size ratio of diverse models of the different species were done in order to control the accuracy of the reconstruction with respect to the available skeletal information in literature.

Also, I am deeply irritated that they misspelled Mark Witton's name in two places in the paper. 

[suspsy]

And to echo what @Halichoeres wrote, published papers on dinosaurs or any other branch of science are never set in stone and should not be treated as such. Scores of papers get retracted every single year. Others are debunked by new findings.

That said, it's not enough to simply say that a published paper might be wrong; you have to be able to conclusively demonstrate that there are errors present. Which can be done in this case.

[Faelrin]

@Halichoeres You make excellent points here. I've seen a number of problematic peer reviewed studies, that had issues such as clear biases, poor sample sizes, etc, and obviously ethical issues such as the Oculudentavis and Ubirajara ones (which should never have been published in the first place). I am hoping enough noise is made about this so that it can be retracted or corrected. This is not a good look for the authors or the platform that published this. Just comparing some of these figures to the skeletals provided quickly shows how problematic many of these figures are, in regards to proportions, etc, like the too large arms on the Papo Ceratosaurus, or the numerous issues the Allosaurus has (pronated wrists, shape of the skull, etc), and obviously the wrong skull shape, etc on the Rebor Tyrannosaurus.

Also this is such a strange mishmash of figures as well, some of which have been retired and off the market for many years now. I think hiring a paleoartist that understands the anatomy of these animals would have provided much more accurate results in an analysis such as this. If they absolutely must use models however there are some much better alternatives out there such as the 2019 Safari Ltd or 2021 PNSO Allosaurus, the 2018 CollectA Deluxe Ceratosaurus, the 2017 Safari Ltd Feathered Tyrannosaurus or the 2020 PNSO one (which although they both have issues with integument, are pretty decently proportioned). At least they didn't use the Papo Baryonyx here.

I will say that the best of these is clearly the Safari Ltd Coelophysis, which is also currently the only one still on the market for that particular animal to my knowledge.

[stargatedalek]

Researchers creating their own 3D models for studies like this isn't itself anything new, but using retail products at face value is beyond merely incompetent.

[Dinoxels]

Honestly hilarious that this happened, some of the figure choices I think were good, others (i. e., Rebor Tyrannosaurus and Papo Allosaurus) confuse me. Like, the figures contradict the skeletals shown. Also isn't this a copyright issue if they don't credit the companies?

[ITdactyl]

The aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families...

...This work shows how digitization techniques, when applied to proper dinosaur models, provide an extent and accurate data set that may help in diverse study areas within the dinosaur palaeontology from ecology and feeding behaviour to the analysis of their locomotion or metabolic rates.

TLDR: I don't disagree with the points of OP @Halichoeres . I'm just presenting a different take on them.

The authors picked a selection of figures to present a better way of getting morphometric information. They were aware of the issues with the models selected, but picked them anyway to demonstrate their methodology.
I'm aware that there are better models available and we don't know why the authors didn't seek those other models, but that's a moot point.

I was also under the impression we agree that "peer reviewed" just means its a better quality read/information but not set-in-stone truth. I'm not surprised this paper passed peer review - it wasn't a research paper on any dinosaur per se. It was a demonstration of the viability of getting data from 3d scanning models. I think this is better than the older method of estimating mass, volume, running speed etc. by using ovoids and cylinders in computer projections.

As for hating the use of "scientifically accurate palaeoreconstructions" in this paper - I think we're just attacking the buzz words. The authors themselves were aware of the issues with each model. They're not saying the Papo Allosaurus represents the real creature. They're saying: give me an allosaurus model, and I can provide you morphometric data to compare to your other findings.

[Dinoxels]

The aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families...

...This work shows how digitization techniques, when applied to proper dinosaur models, provide an extent and accurate data set that may help in diverse study areas within the dinosaur palaeontology from ecology and feeding behaviour to the analysis of their locomotion or metabolic rates.

TLDR: I don't disagree with the points of OP @Halichoeres . I'm just presenting a different take on them.

The authors picked a selection of figures to present a better way of getting morphometric information. They were aware of the issues with the models selected, but picked them anyway to demonstrate their methodology.
I'm aware that there are better models available and we don't know why the authors didn't seek those other models, but that's a moot point.

I was also under the impression we agree that "peer reviewed" just means its a better quality read/information but not set-in-stone truth. I'm not surprised this paper passed peer review - it wasn't a research paper on any dinosaur per se. It was a demonstration of the viability of getting data from 3d scanning models. I think this is better than the older method of estimating mass, volume, running speed etc. by using ovoids and cylinders in computer projections.

As for hating the use of "scientifically accurate palaeoreconstructions" in this paper - I think we're just attacking the buzz words. The authors themselves were aware of the issues with each model. They're not saying the Papo Allosaurus represents the real creature. They're saying: give me an allosaurus model, and I can provide you morphometric data to compare to your other findings.

The authors even reference this, probably should have read the article myself before making an opinion. Point still stands that it's rather odd for them not to seek more accurate models, but regardless they ain't saying they are accurate.

According to this Coelophysis (0.08%) and Baryonyx (0.09%) are the most accurate models whereas Ceratosaurus (0.40%) is the less accurate model.

[dyno77]

It seems lazy to me that they would just pick these rather than going for high quality resin sculpts which are generally more accurate in shape and proportion...

[Sim]

If they absolutely must use models however there are some much better alternatives out there such as the 2019 Safari Ltd or 2021 PNSO Allosaurus, the 2018 CollectA Deluxe Ceratosaurus, the 2017 Safari Ltd Feathered Tyrannosaurus or the 2020 PNSO one (which although they both have issues with integument, are pretty decently proportioned).

In the paper the authors say that figures without a "feather entanglement" were chosen (entanglement is such a weird choice of word...) to avoid overestimation of body mass due to volume... ...With the exception of Coelophysis, which makes me wonder if this really mattered too much.  I think this does bring up something inevitable though...  And that is that there isn't a good featherless Tyrannosaurus on the market that doesnt cost a lot.  As much as I have no interest in a Tyrannosaurus figure, I think it's only a matter of time before Safari releases a new featherless T. rex, there's a gap in the market for it.  CollectA had that chance but didn't use it instead releasing a T. rex (the "roaring" one - could dinosaurs even do that?) that is pretty poor in almost every way (feathering, scales, pose, colours).

Also isn't this a copyright issue if they don't credit the companies?

They do credit the companies.

They were aware of the issues with the models selected, but picked them anyway to demonstrate their methodology.

The only inaccuracies I saw them mention were the pronated hands on the Allosaurus, and the Ceratosaurus being the least accurate of the models they scanned.  But with regards to the Ceratosaurus, I notice they were testing Ceratosaurus nasicornis, while the Papo figure they scanned represents Ceratosaurus dentisulcatus.  Even if these two Ceratosaurus species represent different growth stages of one species, they have different proportions with dentisulcatus appearing to have a bigger head which could make the figure seem more inaccurate than it really is.  It might be the most inaccurate figure to skeletal used but that in part is due to two different specimens being represented.

It seems lazy to me that they would just pick these rather than going for high quality resin sculpts which are generally more accurate in shape and proportion...

...And much more expensive.

[ITdactyl]

@Sim
1. you're right. The pronated hands of the Allosaurus is the only "inaccuracy" they noted and consecutively ignored since it doesn't affect their calculations. They also noted that the tails probably needed more mass (though they didn't list this as an "inaccuracy").

2. The same is true for Ceratosaurus. They ignored the pending resolution for the 3 species, and focused on scaling the figure with USNM 4735 (5.9 m). Their calculations resulted in a Ceratosaurus that would've weighed 1337 kg in life, when proposed estimates for USNM 4735 ranges from 550 - 670 kg.  So, either the toy was sculpted with too much mass (easy assumption) or theropod workers are too conservative with their mass estimates (unlikely, but a good point for further study).  Makes me curious to see the results if they had scaled it to a 7m dentisulcatus.

3. The results for the Allosaurus is interesting. They scaled it to 6.36m individual based on YPM 1930 and got a mass of 1086 kg. Compare their findings to those from different estimates for the same museum specimen:
Alexander and Seebacher: 952 kg
Colbert: 2090–2300 kg
Campione et al.: 2681 kg
Paul: 1700 kg
Therrien and Henderson: 700 kg
To me this is thought provoking (at the very least) because: 1. We know Paul likes his dinosaurs very lean, 2. We all agree the model used looks very famished and 3. it seems a lot of the scholarly estimates for Allosaurus skew towards the Victoria's Secret model weight class.

I, for one, think the team and this paper accomplished their goal; regardless of what we may think of their figure selection. And I am especially glad that they (whether intentional or incidental) chose the wrong Allosaurus model because out of all the models listed, it drove the important points home (that models are being sculpted lacking the necessary mass of the living animal AND that scientists can sometimes underestimate the mass of their subjects)

[Halichoeres]

The aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families...

...This work shows how digitization techniques, when applied to proper dinosaur models, provide an extent and accurate data set that may help in diverse study areas within the dinosaur palaeontology from ecology and feeding behaviour to the analysis of their locomotion or metabolic rates.

TLDR: I don't disagree with the points of OP @Halichoeres . I'm just presenting a different take on them.

The authors picked a selection of figures to present a better way of getting morphometric information. They were aware of the issues with the models selected, but picked them anyway to demonstrate their methodology.
I'm aware that there are better models available and we don't know why the authors didn't seek those other models, but that's a moot point.

I was also under the impression we agree that "peer reviewed" just means its a better quality read/information but not set-in-stone truth. I'm not surprised this paper passed peer review - it wasn't a research paper on any dinosaur per se. It was a demonstration of the viability of getting data from 3d scanning models. I think this is better than the older method of estimating mass, volume, running speed etc. by using ovoids and cylinders in computer projections.

As for hating the use of "scientifically accurate palaeoreconstructions" in this paper - I think we're just attacking the buzz words. The authors themselves were aware of the issues with each model. They're not saying the Papo Allosaurus represents the real creature. They're saying: give me an allosaurus model, and I can provide you morphometric data to compare to your other findings.

That's fair enough. The method itself isn't completely useless, but claims like that really ought to have been filtered out at some stage in the review or editing process.

[bmathison1972]

the bottom line is that they are trying to extrapolate scientific data from toys. Commercial toys.

Conceptually it's not a bad idea, but they should have designed their own models based on available fossil data, or collaborated with someone who could. it would still be hypothetical, but at least it would be more scientifically sound.

[andrewsaurus rex]

if this month was April, I would have assumed this was a joke.   Is another paper going to use Mattel Jurassic World figures?

[andrewsaurus rex]

the bottom line is that they are trying to extrapolate scientific data from toys. Commercial toys.

Conceptually it's not a bad idea, but they should have designed their own models based on available fossil data, or collaborated with someone who could. it would still be hypothetical, but at least it would be more scientifically sound.

another big problem with what they did is the figures are too small to get anything but vague estimates of body mass, even if the Papo toys used were perfectly scientifically accurate (which they really, really ain't).