Amargasaurus neck spines question

[Sim]

On the Amargasaurus Wikipedia page it says the neck spines of Amargasaurus "were bifurcated along their entire length, forming a double row."  I believe this is what is seen in the Amargasaurus by PNSO, the Carnegie Collection and Battat.

However, skeletons of Amargasaurus appear to show that the first neck spine is single, not paired, e.g.:
1. https://commons.wikimedia.org/wiki/File:Amargasaurus,_MEF_Trelew_01.JPG
2. https://commons.wikimedia.org/wiki/File:Amargasauruscazaui.JPG
3. https://commons.wikimedia.org/wiki/File:Dino_amargasaurus.jpg
I think this is what is present on the Amargasaurus by Papo and both versions of Amargasaurus by CollectA.
I've also found a paper that says concerning Amargasaurus

The  species  that  we  describe  possesses  13  cervical vertebrae  that  are  characterized,  except  the  atlas and  the  axis,  by  a  deep  partition  of  the  neural spine that extends to the roof of the neural canal.

To me this suggests at least the first spine is indeed single, and this is shown in an illustration in the paper that is said to be of the atlas and axis although it only shows one spine.  This is the paper: https://paleoglot.org/files/Salgado&Bona_91.pdf

Following on from the above, the Wild Safari Amargasaurus has two single neck spines, the first and the second.  The CollectA deluxe Amargasaurus has a single little pointed structure as well, but it doesn't look like it's meant to be something with a bone core.  So, dare I ask which spine arrangement is correct?  Are the nicest-looking Amargasaurus all inaccurate?  Could the most accurate one be one of the CollectA versions?  Or is it the Wild Safari?  Do we need Schleich or Favorite to make an accurate Amargasaurus?

[Halichoeres]

Yeah, I think it's correct that the the axis does not have a bifurcated neural spine. And therefore, yes, the best looking models are inaccurate in this respect. Most of the nicest ones also have a twin sail, which is probably also incorrect. Maybe this would be a good candidate for an @Eofauna model, since the major companies probably won't revisit it for a while.

[BlueKrono]

Do we need Schleich or Favorite to make an accurate Amargasaurus?

I wouldn't look to Schleich for accuracy. Did you see the Agustinia they just released?

[austrosaurus]

I would say the CollectA deluxe version is probably the most accurate mass-produced Amaragasaurus on the market at the moment. Like @Halichoeres said, I wouldn't expect a new version from any major company other than Schleich, which is bound to be a major disappointment.

[Shonisaurus]

Honestly, none of the versions of toy bitterness of any brand seem convincing to me except the Favorite brand whose figure is a resin dinosaur. I have faith that Favorite Soft Model (PVC) will in the future make a amargasaurus of the same quality as its resin counterpart.

Schleich if they wanted to, they could make a good amargasaurus as was their dracorex or triceratops.

On the other hand, a pretty good amargasaurus is the Safari amargasaurus although I do not know if it is necessary paleoartistically, the one that may be precise may be the Collecta amargasaurus Deluxe but honestly that figure does not convince me especially the part of the head.

[Kapitaenosavrvs]

I was always wondering, how a double Sail on a long neck would behave with Wind or Storm. Sails on big Animals in general. This would be a totally weird and unpractical "decision" from Nature. Ok, Nature is weird most of the Time, but i prefer the Version with a single row and without a Sail.

[Sim]

@Halichoeres, thanks for your reply.  Eofauna could be a good choice for a new Amargasaurus figure.  I'm hoping Favorite would make one too.

@BlueKrono, ha ha, I wouldn't have considered Schleich for something accurate in the past, but I was thinking how an Amargasaurus would turn out if it was made by the sculptor of the newest Schleich Spinosaurus or Baryonyx.  I guess it most likely still wouldn't be 100% accurate, since the Baryonyx has a short tail for example.  I guess Favorite would be more likely to make a good Amargasaurus.

A @austrosaurus, thanks for your reply.  The CollectA deluxe might be the most accurate, but I doubt the real animal would have sails as on this figure where it looks like stuff would get caught in the area where the sails end on the back.

@Shonisaurus, I hope Favorite makes a soft model Amargasaurus!  I think you're right that Schleich could make a good Amargasaurus if they wanted to, but I don't know if they want to.

@Kapitaenosavrvs, it seems most likely Amargasaurus didn't have sails due to the shape of its spines and since sails would reduce the ability of the neck to bend.  But it appears only the first spine is single, with the rest being a double row.

[Faelrin]

Thanks for sharing this information. I also hope to see Amargasaurus done by Eofauna or Favorite eventually.

[Duna]

Yes, you are right, the description in the article is very clear:

The species that we describe possesses 13 cervical vertebrae that are characterized, except the atlas and the axis, by a deep partition of the neural spine

The first two cervical vertebrae (atlas and axis) have a single spine.

I don't think they hold a full double sail at all. Imagine the amount of folded skin that may it had between one spine and the following to permit the normal movement of the neck to look backwards, or just to drink. I see it more like Bajadasaurus. And if it had the double sail, it would have had a closed extreme when it started to be double after the axis. No extant animals have something that could be like a deep trash pit with no posibility to clean ...

[stargatedalek]

Sounds like the Safari version gets everything right then?

[Blade-of-the-Moon]

I used the Safari one to build our sub adult Amarga :

[Sim]

@Duna: Good points!

@stargatedalek: The Wild Safari Amargasaurus might get everything right.  I'm not sure if the second spine was single or paired in the real animal.  Photos of Amargasaurus skeletons seem to show it was paired.

? @Stolpergeist: Interesting that Bajadasaurus has the first spine single too.  Doing a Google images search for "dicraeosaurus skeleton" brings up a photo that shows this condition in the vertebrae as well, where the first has a single projection and then the projections become paired.  I think it's perhaps possible that the second spine of Amargasaurus could've been single through individual variation, I knew a guy who had an odd number of teeth because from what I remember at the front of his lower jaw he only had one tooth and there was no space for the missing tooth.  Maybe even having the first spine paired could have been possible for Amargasaurus through individual variation.

[Halichoeres]

Just to clarify: a tetrapod atlas usually lacks any kind of neural spine; it will have at most an articular process in roughly the position where you'd expect a neurapophysis. So the atlas-axis complex should have a single neural spine, borne on the axis, and it should not be split. All subsequent cervical vertebrae should have a split spine, so I think the Safari is unequivocally wrong on this detail. The first spine also appears to erupt too far posteriorly. The CollectA is less wrong on this detail, although it has a tiny spine on the occiput that is purely speculative. It is, moreover, an extremely ugly figure and doesn't even have sauropod-like forefeet.

[Sim]

Thanks for the explanation, @Halichoeres.