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Mischief-causing titanosaur by ScottHartman Mischief-causing titanosaur by ScottHartman
Rapetosaurus, a reasonably complete titanosaur from Madagascar that lived at the very end of the Cretaceous. This is mostly based on the 26 foot long "juvenile" specimen FMNH PR 2209.

Sauropods aren't really known for wild changes in their proportions as they grow, but at half the length and not even 1/4 the mass of an adult, clearly some changes may have occurred (the one trend that we do see is necks tend to lengthen somewhat and legs tend to get proportionately shorter - although much of that change should have already taken place at this age).

Also, from other specimens we know that the adults had armor nodules on them, but there isn't any evidence for ossified armor on the juvenile specimen, so I didn't illustrate them (also, this saved me a lot of time!).

Edit: Updated silhouette, although in this case the difference is quite a bit more pronounced than in some other taxa.
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:iconyutyrannus:
Yutyrannus Featured By Owner Edited Jul 12, 2015  Hobbyist Traditional Artist
What would you say is the most likely type of osteoderm to have been present in lognkosaurs?
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:iconyutyrannus:
Yutyrannus Featured By Owner Jul 10, 2015  Hobbyist Traditional Artist
Ah, okay.

Well, I still have plenty of time so I'm not in that much of hurry, but I will probably try that out anyway :).
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:iconpedrosalas:
PedroSalas Featured By Owner Apr 30, 2014  Professional Traditional Artist
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:iconalgoroth:
Algoroth Featured By Owner Aug 5, 2012  Professional General Artist
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.
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:iconscotthartman:
ScottHartman Featured By Owner Jan 7, 2015  Professional Digital Artist
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.
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:iconalgoroth:
Algoroth Featured By Owner Jan 8, 2015  Professional General Artist
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. 
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:iconscotthartman:
ScottHartman Featured By Owner Jan 9, 2015  Professional Digital Artist
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.
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:iconalgoroth:
Algoroth Featured By Owner Jan 10, 2015  Professional General Artist
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.
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:iconbrainmatters:
Brainmatters Featured By Owner Jul 24, 2012
How does this thing even stand like that? :o
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:iconzegh8578:
ZEGH8578 Featured By Owner Mar 2, 2013
You're thinking about balance? Have in mind you are only seeing a flat animal in profile. In life, the torso is very very heavy - more than heavy enough for the neck not to be able to tilt it over. It could stand perfectly fine :]
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:icontrue-leveller:
True-Leveller Featured By Owner Mar 3, 2013  Hobbyist Traditional Artist
Also the neck is filled by one giant airsac and the bones are also the most pneumatic ones, generally spoken. This makes the neck much lighter than it looks, even if watched in 3d.
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:iconpaleojoe:
PaleoJoe Featured By Owner Mar 18, 2012  Student Traditional Artist
How big(or small) would this or any adult be
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:iconscotthartman:
ScottHartman Featured By Owner Mar 19, 2012  Professional Digital Artist
The authors estimated that adults would exceed 50 feet in length. Assuming the proportions don't change much, I'd guestimate 20ish tons.
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:iconvasix:
vasix Featured By Owner Jan 6, 2015  Hobbyist Digital Artist
But...exceed 50 feet? By how much, would you say?
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:iconscotthartman:
ScottHartman Featured By Owner Jan 7, 2015  Professional Digital Artist
Don't know, the adult specimens aren't well enough known to tell for sure.
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:iconblazze92:
bLAZZE92 Featured By Owner Aug 31, 2013
20ish tons sounds too much for an animal that, based on your skeletal, would only be ~3.3m in skeletal shoulder height at 50ft in length, didn't you meant to type 10ish tonnes? though IMO, being only slightly taller than an average bull african elephant makes me thing that's still too much.
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:iconscotthartman:
ScottHartman Featured By Owner Jan 7, 2015  Professional Digital Artist
You mean I need to actually think about it??? You're right, 15 tonnes does seem a bit big. 10-maybe 15 tonnes (depending on if any proportions scale allometrically) is more realistic.
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:iconpaleojoe:
PaleoJoe Featured By Owner Mar 31, 2012  Student Traditional Artist
Okay.
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:iconanimaniac888:
Animaniac888 Featured By Owner Mar 17, 2012  Hobbyist General Artist
I find it absolutely the neck to body proportions absolutely mind boggling, especially on an animal this size. I would expect a longer tail for a counterbalance, and a LOT more musculature. Then again, somebody 200 million years in the future might say the same about giraffes. They have no tail at all for counterbalancing. Nature works in mysterious ways.
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:iconscotthartman:
ScottHartman Featured By Owner Mar 19, 2012  Professional Digital Artist
Yeah, there doesn't seem to be any correlation between neck and tail size - I think quadrupedal animals are under a bit less stress in terms of limitations due to imbalance.
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:iconanimaniac888:
Animaniac888 Featured By Owner Mar 19, 2012  Hobbyist General Artist
Oops. *facepalm* I totally forgot to take into account that quadrupedal animals would require less in terms of a counterbalance. Still, the size of the neck is totally crazy. I remember reading a theory in either the book Jurassic Park or The Lost World that said that sauropods would have had to keep their heads close to the ground most of the time.
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:iconidleprodigy:
IdleProdigy Featured By Owner Mar 20, 2012
The cervical air sacks probably improved their balance as well - at least that's what I tell myself whenever I see a sauropod skeletal and instinctively expect it to fall flat on it's face :worry:
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:iconanimaniac888:
Animaniac888 Featured By Owner Mar 21, 2012  Hobbyist General Artist
Did dinos have cervical air sacs? Excuse my ignorance, as I'm not that well versed in dinosaur anatomy. Before today, I had no idea what a cervical air sac was.
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:iconidleprodigy:
IdleProdigy Featured By Owner Mar 22, 2012
In that case, seek out the sauropod enamoured bloggers of SV-POW. They've been writing about this stuff for ages and their tutorial on pneumaticity from 2007 is an excellent place to start [link]
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:iconanimaniac888:
Animaniac888 Featured By Owner Mar 22, 2012  Hobbyist General Artist
Thanks, it was an interesting read.
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:iconidleprodigy:
IdleProdigy Featured By Owner Mar 23, 2012
You're welcome :)
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:iconpaleo-king:
Paleo-King Featured By Owner Mar 12, 2012  Professional Traditional Artist
Gorgeous! Better than Greg Paul's hasty treatment of this specimen, and a whole lot better than Mark Hallett's awful short-necked "saltasaurized" version. Oddly, the big "shark fin" neural spines on the neck seem to imitate Futalognkosaurus: [link]

BTW is there any trace of bifurcation in any of the neural spines in any specimen of Rapetosaurus? I didn't see any in the papers that have some out so far, but these only contain pictures of the juvenile specimen. And did they actually find the hyoid?
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:iconscotthartman:
ScottHartman Featured By Owner Mar 12, 2012  Professional Digital Artist
Thanks - it was fun to take a walk on the titanosaur side of the tracks! To be fair to Mark, he was doing that work before the postcranial description (and I believe before a lot of it was prepped out), so I imagine a lot of the instruction he was given involved the phrase "make it look sort of like this...".

I agree that it's very interesting that Futalognkosaurus (I hate that name) uses the same sort of cervical neural spine shape. And no, there isn't a trace of neural spine bifurcation, although I haven't seen most of the adult specimens.

Finally, they did indeed find the hyoid. Ironically I'm doing two skeletals in a row where the hyoid was found, so I may just start to illustrate them, although obnoxiously that will mean going back and adding more than a hundred hyoids to previous skeletals...
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:iconemperordinobot:
EmperorDinobot Featured By Owner Mar 11, 2012
Oh I had been waiting for this one!
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:iconscotthartman:
ScottHartman Featured By Owner Mar 11, 2012  Professional Digital Artist
You were? Why didn't you say so?!!

;)
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:iconemperordinobot:
EmperorDinobot Featured By Owner Mar 12, 2012
GP's seems like a mashup, as does Zack Armstrong's. I wanted to do one with a vertical neck but the verts don't seem to articulate that way.
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:iconscotthartman:
ScottHartman Featured By Owner Mar 12, 2012  Professional Digital Artist
Ooh, I haven't seen Zach's - do you have a link? (yes, Google seems to have failed me here).
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:iconemperordinobot:
EmperorDinobot Featured By Owner Mar 12, 2012
I think he deleted it. Heee.
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:iconpilsator:
pilsator Featured By Owner Mar 11, 2012  Hobbyist Traditional Artist
Beautiful as always, Scott!
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:iconhellenicwarrior:
hellenicwarrior Featured By Owner Mar 11, 2012  Hobbyist Traditional Artist
Very nice
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