My modified Brach's "nose"

[Paleogene Pals]

It is the core wire that is exposed. I'm not happy with the shape of the front spines so still trying to figure out what to do with them.  I still want to make them different from the rest of the spines, however. I agree that my interpretation is unlikely to be scientifically accurate. But, maybe I'm making a statement about science vs. art.

Interesting how much discussion a pair of brach nostrils has generated 

[Blade-of-the-Moon]

It is the core wire that is exposed. I'm not happy with the shape of the front spines so still trying to figure out what to do with them.  I still want to make them different from the rest of the spines, however. I agree that my interpretation is unlikely to be scientifically accurate. But, maybe I'm making a statement about science vs. art.

Interesting how much discussion a pair of brach nostrils has generated 

Not prompted in the least by your wonderful sculpture ! lol 

[Paleogene Pals]

I'm glad everyone likes what I do. It has been my lifelong dream to be a paleoartist.

[wings]

Regarding spines, I'm not arguing over whether they could have existed or not. They simply seem unnecessary to me from a scientific perspective (but they look great from an artistic point of view). So I'm leaving this to the choice of the artist. Because only in Diplodocoidea have remains of spines been seen. It seems that there is a tendency whithin this group, (e.g. Amargasaurus). Personally, I prefer to consider Diplodocoidea as the only group of Sauropods with spines.  So not all sauropods would be exactly equal (which to me renders this group more "natural"). But as I said, my interpretation of spines is not strong, I will be very happy to change my opinion  if one day remains of spines are found in Macronaria.

"Scientific perspective"? Is there any base to this? Are there any evidence that indicate this kind of structure is size dependent (to my understanding from your initial comment)?



Since you prefer to consider Diplodocoidea as the only group of sauropods with spines then you would probably assume that Supersaurus (E, above) would also have them. However, size wise this (Supersaurus) is very similar to Brachiosaurus/Giraffatitan (I and J); then are you saying Supersaurus shouldn't have them? So is your "scientific perspective" based on family or size?

http://dml.cmnh.org/2001Feb/msg00655.html

All we know for now is that we have a Barosaurus/Diplodocus that has "spines" along the top of its tail. Does the row extend along the body or even the neck? We just have no idea. We also know that these "spines" vary in shapes (from narrow pointed to wide and blunt, Czerkas 1997); So I suppose some of the wide blunt ones could be referred to as scutes. These (spines/scutes) might spread around the body as Scott implied in his post (no strong association with the dorsal midline). Come to think of it with the scutes spread around the body does this remind you of another family of sauropods? Like the Titanosauriformes such as the armor on Saltasaurus... It does seem like that these kind of "dermal" modifications are quite widespread among the sauropod group. This is not a direct proof of whether Brachiosaurus should have "spines" along its back but what this does show is that it is a possibility rather than an inaccuracy. Honestly I don't mind either way (since there is no direct evidence, like trace fossils of "skin" on the back of Brachiosaurus) and to say it as unscientific at this point I find it is just misleading.

[Paleogene Pals]

Isn't this similar to arguing about how many angles can dance on the head of a pin. Considering how few fossils we have of many dinosaurs (as opposed to something like conodonts) and the scarcity of soft-tissue preservation, we will never truly know what these things looked like unless we manage to send someone back in time with a digital camera.  For all we know, Brachiosaurs could be pink with purple polka dots and have daisies lining their backs.

Of course, I'm just a humble biostratigrapher so am not aware about how much material there really is on sauropods.  At Iowa, the vertebrates paleontologists would never let the likes of me hand with them. 

[Megalosaurus]

Is perfectly fine to put especulative features like you did in this model.
You know, I'm sick of the classic reconstructions that are just "skin over a skeleton". Don't let you that others discourages you from being creative and using your mind to imagine dinosaurs as the real animals they were.
Keep going on this way. I love what you did to this sauropod.

[Lythronax]

Sorry for the delay in answering.

I think that what I intended to convey has been misunderstood, probably because I'm writing in a language I'm not fluent in. By no means do I intend to limit anybody's creativity. I said that I didn't think the dewlap exists in sauropods and I didn't said that putting spines on the Brachiosaurus back was incorrect, because there is no evidence against their existence, of course everybody is free to put them if they wish so.

I think I was not clear in my explanations. When I said:

Regarding spines, I'm not arguing over whether they could have existed or not. They simply seem unnecessary to me from a scientific perspective

Here I don't say anything more than what is written. I make no reference to differences in size or family. It just doesn't seem that there be any selective pressure that favors the existence of these structures. Then, in my opinion it's not strictly necessary that any sauropod has spines. Researchers found spines in Barosaurus/Diplodocus, which is mentioned by Wings. So I can't say to anybody that putting spines on a sauropod it is "right" or "wrong", I simply said that these structures may not be necessary to increase the fitness of any sauropod.

From this point on, may everybody do what they want, of course. In my opinion, Paleogene has put spines that are plausible but not strictly necessary. I don't think that anybody can interpret this as meaning that Paleogene is wrong, rather than emphasizing that this is his choice.

I said this:   

Regarding spines, I'm not arguing over whether they could have existed or not. They simply seem unnecessary to me from a scientific perspective

From this it doesn't follow that putting spines in Brachiosaurus is an inaccuracy. On the contrary, because spines are, no more no less, a possibility (some sauropods had spines), Brachiosaurus could have had them or not.

With regard to the question Wings asked me before:

Since you prefer to consider Diplodocoidea as the only group of sauropods with spines then you would probably assume that Supersaurus (E, above) would also have them. However, size wise this (Supersaurus) is very similar to Brachiosaurus/Giraffatitan (I and J); then are you saying Supersaurus shouldn't have them? So is your "scientific perspective" based on family or size?

And why should spines be linked only to size of family? Why can't we think that the two factors interact at the same time with other factors that we don't have in mind? In my first-ever post in this forum I mentioned the problem that Paleontology has been carrying around, namely that it failed to properly incorporate a biological perspective in the interpretation of fossil remains. I also said that this problem is being gradually corrected.

It's obvious that from a scientific point of view we can't state whether most sauropods had or didn't have spines, because evidence is lacking. Therefore, it is correct to reconstruct them both with and without spines. Now, from the interpretation of the evidence available, paleoartists can give coherence to the group they are reconstructing, rather than to a single species. At present we can see that a given group of extant organisms is not morphologically homogeneous. This morphological heterogeneity is partly due to the different selective pressures that each species is subjected to. And it can be partly due to the intrinsic characteristics of the group, which in some cases can get lost but that are overall kept in the group. Likewise, these characteristics typical of a group can now and then arise in species from other groups due to selective pressures. Now that we are dealing with crests, spines and scutes I will go into Squamata as an example of what I'm talking about. Many times, when people think of a lizard, they picture it with a crest. But actually, among lizards, the only group with crests and spines is Iguania (iguanas, chameleons, agamids), whereas other lizards (Anguiomorpha, Gekkota, Lacertoidea and Scincomorpha) normally don't have a crest. Now, there are exceptions such as the Common collared lizard (Crotaphytus collaris), an Iguania that doesn't have either crests or spines. And there are also non-iguanid lizards with such structures: in Gekkota there is the Crested gecko (Correlophus ciliatus), with a crest, and the spiny-tailed geckos (Strophurus sp.) or wall geckos (Tarentola sp.), both with spines. From a scientific perspective, the presence of crests in these examples is not strictly necessary to increase the fitness of the lizards in Iguania, because there are many lizard species that occupy the same ecological niches that don't have either crests or spines and survive quite well, these are Varanidae and Lacertoidea. Therefore, most crested and spined lizards are in the Iguania group simply because in this group there is a propensity to express this character (it can be that this character is beneficial in some environments and makes them prevail over other species, but it need not be the case).

Back to Sauropods. I already said that paleoartists are able to do one thing that paleontologists are not allowed to, that is reconstruct fossil forms from the available information and fill in the gaps while making their personal interpretation of prehistoric life, which must be plausible. To my mind (personal interpretation), it is more coherent to think that a large group like sauropods can have subgroups that, among other things, can diverge on characters that are not strictly necessary to individual survival. This makes them more realistic than they would be if they were all reconstructed in the same way (in this case, without crests or spines). This doesn't mean that my interpretation is true, rather than in addition to the lack of data, this is a representation of PaleoDiversity more similar to Extant Biodiversity (this is what I wanted to convey with the word "natural"). But because it is only a speculation of mine, if further evidences on spine presence in Sauropods are found and if these indicate that spine presence was generalized among Sauropods, I will change my interpretations.

Now I turn to Supersaurus, which Wings mentioned before. After my interpretation about the existence of a trend in Diplodocoidea to present spines/crests, Supersaurus should be reconstructed with spines. However, because it's a large species, it could be that the spines would be even more unnecessary and so they could have become smaller, or even not expressed phenotypically (as a means to save energy). If this were the case, Supersaurus could resemble Brachiosaurus in a case of convergent evolution. Regarding Macronaria, maybe they did have spines. For instance, Europasaurus is a small sauropod, more vulnerable than others to the attack of predators like Balaur or Azhdarchidae. In this case, it may have been more "interesting" to have spines than scutes (who knows?), because it was not able to grow further because it distribution was restricted to an island.

I'm not saying that this interpretation is more correct from a scientific point of view, because it's just a speculation due to lack of information. But I do think that, like at present, groups need not be homogeneous, and less so when it comes to characters that don't seem to significantly influence the fitness of individuals. Anyway, it's only my personal interpretation I think any person is free to have their own opinion.

Interesting how much discussion a pair of brach nostrils has generated 

Definitely!

[wings]

...And why should spines be linked only to size of family? Why can't we think that the two factors interact at the same time with other factors that we don't have in mind? ...if further evidences on spine presence in Sauropods are found and if these indicate that spine presence was generalized among Sauropods, I will change my interpretations.

...because it's a large species, it could be that the spines would be even more unnecessary and so they could have become smaller, or even not expressed phenotypically (as a means to save energy).

If that was the initial idea (in bold) then I don't see why we are having this discussion. Since we actually do have evidence that perhaps some Macronarians might have these ornaments; such as "scutes" were found on Titanosauriformes (previous post). Not saying this proves brachiosaurus has them but it demonstrates a reasonable possibility for this group to develop them.

Also to clarify some of the found "spines" on the Diplodocus/Barosaurus are shaped quite "disc/scute-like" and they are fairly flat and blunt (again from previous post).

I suppose it all comes down to bad wording; just because you think it is "unnecessary" does not imply it's scientific based (scientific perspective). Whether it is necessary; I'm not sure whether we have the mean to work this out for certain. Talking about Azhdarchidae, if we take Zhejiangopterus and Quetzalcoatlus for example; if I'm applying the same "logic"; I would be expecting to see the smaller Zhejiangopterus to be more "ornated" compare to Quetzalcoatlus; however,  Zhejiangopterus is crestless while Quetzalcoatlus has a "humped" crest...

[Paleogene Pals]

So, I have been doing some thinking on the whole what is necessary or what is unnecessary for certain structures.  The spines and wattles I put on my brach serve no actual function and may be a hindrance.  But, think about the colorful tail feathers of a peacock or the fact that some male birds are very colorful while females are drab.  Think about six-pack abs on a human male.  The bright colors on the male bird are unnecessary and even make them easier for predators to see. And, it isn't necessary for males to have a six-pack to survive. 

But, these features do serve one important function, attracting females.  Perhaps the spines and wattles give the male brach an opportunity to put on a brilliant display for the female brachs.  Maybe the brach I made would be considered the Tom Cruise or Brad Pitt of the Jurassic plains. 

Just something I thought about.

[ITdactyl]

... Think about six-pack abs on a human male. ... it isn't necessary for males to have a six-pack to survive. 

hahahaha!  This made my day.

I thought the original reason for modifying the brach was to have a model that looks good, and not to be constrained by scientific debates.  Go with your original design.  You know we can't wait for the finished version.