Comment on Mischief-causing titanosaur by DrScottHartman
Cannot give you an official critique.
But an UNOFFICIAL one...YAH!
As always, beautiful artwork. My only other point of reference for this amazing beast is a photo of its skeleton. All I can say is that this looks accurate. To me. Lacking anything else to go on, that is all I can say.
Now, for my opinion. Why is the neck so fleshed out, like it's a horse, but the front legs and chest so skinny? Mummified. The hinder legs look fine to me, at least, to judge from this skeletal.
I'd like to know if there is evidence of withers, like on Giraffatitan. Then I'd buy the neck.
But an UNOFFICIAL one...YAH!
As always, beautiful artwork. My only other point of reference for this amazing beast is a photo of its skeleton. All I can say is that this looks accurate. To me. Lacking anything else to go on, that is all I can say.
Now, for my opinion. Why is the neck so fleshed out, like it's a horse, but the front legs and chest so skinny? Mummified. The hinder legs look fine to me, at least, to judge from this skeletal.
I'd like to know if there is evidence of withers, like on Giraffatitan. Then I'd buy the neck.
Many (possibly most) titanosaurs seem to have a distinct alternative to withers, where the anterior (and sometimes even the mid) dorsal neural spines are highly deflected posteriorly, allowing the nuchal ligaments (and probably some musculature) to run over the top of the next neural spine and up the neck.
As for the arms, I did add a bit more muscle on to the updated version at my website: www.skeletaldrawing.com/saurop…
I'm not sure where I can drape any more muscle, outside of maybe adding even more triceps girth. Of course if you want to assume there were thicker tendons or skin on the wrist and hands go ahead (or maybe a larger fleshy pad), but the reason the muscles aren't any larger is because the bones aren't any larger.
As for the arms, I did add a bit more muscle on to the updated version at my website: www.skeletaldrawing.com/saurop…
I'm not sure where I can drape any more muscle, outside of maybe adding even more triceps girth. Of course if you want to assume there were thicker tendons or skin on the wrist and hands go ahead (or maybe a larger fleshy pad), but the reason the muscles aren't any larger is because the bones aren't any larger.
Basing my critique here on some experience with living animals, I have to say, in my opinion, any paleo-artist, including myself, has a hard time adding sufficient and probable flesh to bone working from either drawn skeletals or skeleton mounts. The most tantalizing method is to, as you say, drape the bones with muscles. However, this seldom leads to accuracy, IMO.
One of the most hefty arguments against dinosaurs being warm-blooded of any kind and active was to point out that even the largest dinosaur limb bones showed a lot of evidence for a lot of cartilage. "How could they move around well without solid bone, just thick cartilage pads." Robert Bakker pointed out that thick pads of cartilage absorb shock better than bone. Few fossils show cartilage remains, but it was there.
Does muscle attach to cartilage? According to the chickens I've eaten, yes it does. If the cartilage pads are taken into account, then the muscle outlines are expanded a fair percentage. Take into account also that there was blood and blood vessels, fat, and thick skin and the outlines can increase in size by another fair percentage. How much? Using packaged chicken thighs as a guide, way more than one might think. Same sized container which holds, on average, four thighs with skin and fat on holds six thighs quite comfortably. And then there is the fact that muscles, unlike tendons and ligaments, does not go straight line from attachment point to attachment point, but has a convex outline. All of this adds up. How much? Upper limbs, maybe easily, in a healthy animal, half again and a quarter again for the lower limb elements, all four legs. Can muscles bulge in a wild animal? Yes.
You can say you are not taking fat and skin int account in these skeletals, but when artists use them as guides to flesh out restorations, they are too often treated as "everything is there" guides. Should the lower limbs of quadrupedal dinosaurs be as thickly drawn as the upper limbs? I say no: no erect walkers I know of have thick lower limbs as compared to upper limbs, from humans to the other primates to horses to birds, lower limb elements are thinner. In splay legged endoskeletal beings, the lower limbs often are close to as thick as the upper limbs. Look at lizards and crocodilians for examples.
As for your take on substitutes for withers in titanosaurs: I have no problems with it.
One of the most hefty arguments against dinosaurs being warm-blooded of any kind and active was to point out that even the largest dinosaur limb bones showed a lot of evidence for a lot of cartilage. "How could they move around well without solid bone, just thick cartilage pads." Robert Bakker pointed out that thick pads of cartilage absorb shock better than bone. Few fossils show cartilage remains, but it was there.
Does muscle attach to cartilage? According to the chickens I've eaten, yes it does. If the cartilage pads are taken into account, then the muscle outlines are expanded a fair percentage. Take into account also that there was blood and blood vessels, fat, and thick skin and the outlines can increase in size by another fair percentage. How much? Using packaged chicken thighs as a guide, way more than one might think. Same sized container which holds, on average, four thighs with skin and fat on holds six thighs quite comfortably. And then there is the fact that muscles, unlike tendons and ligaments, does not go straight line from attachment point to attachment point, but has a convex outline. All of this adds up. How much? Upper limbs, maybe easily, in a healthy animal, half again and a quarter again for the lower limb elements, all four legs. Can muscles bulge in a wild animal? Yes.
You can say you are not taking fat and skin int account in these skeletals, but when artists use them as guides to flesh out restorations, they are too often treated as "everything is there" guides. Should the lower limbs of quadrupedal dinosaurs be as thickly drawn as the upper limbs? I say no: no erect walkers I know of have thick lower limbs as compared to upper limbs, from humans to the other primates to horses to birds, lower limb elements are thinner. In splay legged endoskeletal beings, the lower limbs often are close to as thick as the upper limbs. Look at lizards and crocodilians for examples.
As for your take on substitutes for withers in titanosaurs: I have no problems with it.
Sauropods show evidence of a lot of cartilage in the joints, but not on say the deltapectoral crest, or the olecranon process, which are major points of muscle insertion that help define how large the forelimb muscles look in side profile. Despite what you are saying chicken thighs are exactly as massive as their bones dictate, and are correctly restored in skeletal reconstructions of them (though I've not done one myself). In particular they have really elongate ilia to support those thigh muscles. Also, be careful drawing conclusions about market chickens - they are killed when they hit full size but before they hit skeletal maturity; much of that cartilage continues to ossify into bone. Grab and eat an old rooster (make coq au vin?) and check out its skeleton for a more accurate view.
I will say this - massive amounts of tricep, deltoid, and pectoral muscles I restore on these guys are simply not evident in side view because the they are obscured by the torso (in particular the coracoids are curving in away from the arm to meet at the midline - all of that space between there and the deltapectoral crest has a large belly of muscle, but you can't see any of it in a 2D side view).
Technically muscles don't attach to either cartilage or bone, they attach to tendons which insert into bone. Of course those tendons aren't just glued on, they actually undergo a histological change as they penetrate bone or cartilage, until the collagen in them is largely gone and you just end up with bone.
There is nothing to be done regarding blood vessels, the muscle estimates cover those just fine. I do agree that many artists don't take into account skin thickness and (potential) fat deposits in their reconstructions, and I have planned several blog posts on that topic, but at this rate I doubt I'll have time to finish them before the summer.
I will say this - massive amounts of tricep, deltoid, and pectoral muscles I restore on these guys are simply not evident in side view because the they are obscured by the torso (in particular the coracoids are curving in away from the arm to meet at the midline - all of that space between there and the deltapectoral crest has a large belly of muscle, but you can't see any of it in a 2D side view).
Technically muscles don't attach to either cartilage or bone, they attach to tendons which insert into bone. Of course those tendons aren't just glued on, they actually undergo a histological change as they penetrate bone or cartilage, until the collagen in them is largely gone and you just end up with bone.
There is nothing to be done regarding blood vessels, the muscle estimates cover those just fine. I do agree that many artists don't take into account skin thickness and (potential) fat deposits in their reconstructions, and I have planned several blog posts on that topic, but at this rate I doubt I'll have time to finish them before the summer.
I also base my thoughts on wild animals
Seen paintings of chickens with overly skinny legs.
The artist shall remain nameless, though famous. Many pieces of art based on living animals show enough muscle. I am a fan of wildlife art, seen tons of it.
I am talking about paleo-art, in which many pics show fleshed out limbs with skinnier than bone restorations.
Check out a bunch of artists here on dA and on facebook. I will not name names.
Seen paintings of chickens with overly skinny legs.
The artist shall remain nameless, though famous. Many pieces of art based on living animals show enough muscle. I am a fan of wildlife art, seen tons of it.
I am talking about paleo-art, in which many pics show fleshed out limbs with skinnier than bone restorations.
Check out a bunch of artists here on dA and on facebook. I will not name names.