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Brachiosaur comparison by Paleo-King Brachiosaur comparison by Paleo-King
This is my comparison of the core type specimens of Giraffatitan brancai (HMN SII/S116/Aa) and Brachiosaurus altithorax (FMNH P 25107), based on the composite skeletals I did of both.

Giraffatitan: paleo-king.deviantart.com/art/…

Brachiosaurus: paleo-king.deviantart.com/art/…

I used as much material from the types and from similar-sized and similar-morph individuals as possible to reduce any ontogenic distortion or chimeras in the composites. Yes, that means no HMN SI (which is probably a separate genus from almost every other specimen currently in Giraffatitan), and no "Ultrasauros" material for B. altithorax either. Actually, the more compact SI has more in common with some of the referred BYU Brachiosaurus neck vertebrae than with those of Giraffatitan, so the possibility of a stockier, more Brachiosaurus-like taxon coexisting with Giraffatitan in Africa is quite good.

Both individuals here are to the same metric scale (NOT adjusted to the same femur length, though they are close), and conveniently both were apparently around the same ontogenic age when they died - they were "teenagers" in sauropod terms, neither is fully grown, as their coracoids had not begun fusing to the scapula. So you can see how these two individuals would have compared in real life. The Brachiosaurus is a longer animal, mainly due to its bigger tail and longer torso (though its sacrum is actually smaller than Giraffatitan's) and also has a more robust build overall. Giraffatitan has the longer neck and arms.

Scott Hartman's comparison paleo-king.deviantart.com/art/… inspired this piece, though my versions of these animals are purely derived from museum photos and from the original published images in the literature, not based on his skeletals (Hartman's Giraffatitan, like GSP's, oddly seems to use an excess amount of scaled-up juvenile material for hip, limb and neck bones that are already known from SII and other large subadult specimens, which changes the proportions).

The two brachiosaurs are clearly very different in their design. Actually if you compare the two, it is quickly apparent that Brachiosaurus and Giraffatitan were even more different from each other than Hartman's version indicates (he seems to clone a lot of Giraffatitan, unaltered, for gap-fillers in Brachiosaurus). It's even more obvious how the torso lengths differ, and by comparison, bipedal rearing would have looked downright easy for Giraffatitan despite its smaller tail. One thing that shocked me is how much wider Giraffatitan's mouth appears (subadult skull HMN S116, probably the same individual as SII), despite it being a lighter animal with a smaller gut. But then again, we don't have a Brachiosaurus skull of comparable size or maturity to work with - only the Felch Quarry and Reed Quarry skulls, both juveniles only about half the size of the holotype (the Felch skull is scaled up here for B. altithorax). So the more mature holotype may have actually had a wider mouth like that of Giraffatitan, as neosauropods in general widen the mouth proportionally as they grow.
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:icondinopithecus:
Dinopithecus Featured By Owner Apr 30, 2017
So, if I remember everything correctly, brachiosaurs were the only sauropods whose thumb claws directly touched the ground (other sauropods apparently kept their thumb claws cocked upwards off the ground and could move them at the joint, going by Matt Wedel's and Mark Hallett's The Sauropod Dinosaurs: Life in the Age of Giants)?

How far apart could sauropods move their forelimbs from each other? I'd imagine if you want to use those inward-facing claws to create puncture wounds you want to create a substantial amount of clearance between them.
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:iconpaleo-king:
Paleo-King Featured By Owner Apr 30, 2017  Professional Traditional Artist
Brachiosaurs were not the only sauropods to have the thumb claw on the ground, the were merely the first ones.

Laurasiformes and chubutisaurs apparently also had them on the ground or near it, as their thumb metacarpals are long. Also Rapetosaurus and other derived lithostrotians would have them on the ground level too as the thumb metacarpal in those species was about the same length as the other metacarpals. In Diamantinasaurus however the thumb claw is a lot bigger, despite being at ground level.

With Argyrosaurus the thumb metacarpal curves up and inward to give the claw some clearance. This was probably also the case with lognkosaurs to a less extreme degree. Yes the claw wasn't recovered but that is normal in titanosaurs, they had looser connections (more cartilage) between metacarpals and phalanges due to the added weight for any given body length. We know from Diamantinasaurus that the thumb claw was not actually lost in evolution.

As for forelimb spacing, it was narrow in diplodocoids and more basal groups, it was moderate in brachiosaurs and wide in titanosaurs. Ironically in diplodocoids and mamenchisaurs is where you get the most swivel range for the claws due to them being carried off the ground and being a prehensile unit, but they have the narrowest gauge spacing between their arms. So any puncture wounds would be closely spaced with those ones. With titanosauriforms you would be more likely to maul than produce targeted puncture wounds. It's still a bit of an unknown how mobile the claw was in titanosaurs and euhelopodids, and it was fixed in brachiosaurs.
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:icondinopithecus:
Dinopithecus Featured By Owner Edited May 11, 2017
Oh, I didn't know other sauropods also had claws at or near ground level. That's interesting.

I think I remember you mentioning some sauropods biting their predators (like Giraffatitan). I even remember Duane Nash telling me that macronarians could deliver nasty bites as well (he said their jaws and teeth worked like hedge clippers that could bite through thick conifer branches). Is that right?

2.) What do you think of the idea of sauropods in general swinging their necks at predators as a defensive measure?

And, warning, ridiculous question coming up (this is what debating animal vs animal for >4 years does to you):

If you had a magical time machine that managed to get an angry bull elephant and an angry Brontomerus together (both animals weigh about the same)...how would that play out? None of the sauropod's weapons strike me as easy to bring to bear or as deadly as an elephant's tusks so...wouldn't the dinosaur be a goner?
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:iconpaleo-king:
Paleo-King Featured By Owner May 11, 2017  Professional Traditional Artist
1. Some macronarians did have a stronger bite than how they're usually stereotyped. There's no way to prove that they bit at predators, but if you've seen the SV-POW! pictures of the Giraffatitan skull HMN t1 with humans for reference (and that's a juvenile skull, mind you), it's pretty big and those teeth are approaching the size of machine gun rounds. The jaws and skull bones are still pretty light but overall with the cartilage and soft tissue it was a skull with some real power and pretty big fenestrae for jaw muscles. They didn't bite super fast, but they definitely had leverage. They were indeed like hedge clippers, brachiosaurs and other macronarians with similar teeth and mouths were basically hacking through conifer branches with their wide U-shaped mouths. It was messy but it maximized food intake.

I don't think neck swinging was a good strategy because some of these necks were fragile as far as bones went, the cartilage in the tendons outside the bones can cushion come impacts, but unless the neck bones were really bulky like in apatosaurs and some of the later titanosaurs, a direct impact with the neck was likely to be painful.

2. Brontomerus would not necessarily be a goner since its huge thigh muscles meant it could easily pivot around and then the elephant has to deal with those crazy kicks and a big tail which elephants don't have. Also elephants tusks are usually not sharp at the tip and while they can be deadly, they can also be broken with enough lateral impact - something that a sauropod tail hitting them from the side could definitely do. There probably isn't an elephant alive in the wild that hasn't broken a tusk at some point in their life, but the tusks do regrow slowly. You can sometimes tell by one tusk being thicker than the other, the thick one was the one that broke off and regrew from a stub since the base was thicker now that the elephant was larger. I suspect the brontomerus would actually win.

You're right though, this is one of those "you could debate forever" questions, and also it doesn't account for the fact that Brontomerus was probably bigger than an elephant (the Scott Hartman skeletal that uses a scaled-down Camarasaurus as the base proportions is likely not very accurate for a somphospondyl like Brontomerus; the 3d computer models are also probably wrong and too diplodocid-like, too light and short  on the front end). Not only that but the scapula doesn't have a coracoid fused to it so this specimen wasn't done growing, the adults may have been considerably bigger, and probably had to be, in this time of big giant-killers like Acrocanthosaurus and packs of Utahraptors.
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:icondinopithecus:
Dinopithecus Featured By Owner May 12, 2017
As usual, good insight.

Good point on pivoting. I hadn't thought of a sauropod applying weapons that way (similar to stegosaurs and ankylosaurs that would pivot so they could hit attackers with their tails). Where exactly would the Brontomerus kick, though, the elephant's face, tusks, forelimbs?
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:iconpaleo-king:
Paleo-King Featured By Owner May 12, 2017  Professional Traditional Artist
Anywhere. As long as the foot claws landed a blow, the elephant is in trouble. its reaction time would likely not be as fast due to its more slender limb bones and muscles.

If the foot or leg hit the elephants tusks, there could be enough force to break at least one tusk.

We have to imagine Brontomerus being a faster animal, because of its larger muscle attachment surfaces on the shoulder, humerus, and that crazy flared ilium.
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:icondinopithecus:
Dinopithecus Featured By Owner Edited May 13, 2017
Ah, okay.

I was initially wondering if a sauropod could raise its leg high enough to kick an elephant's cranial region, but then I saw this picture (ironically, of an elephant laterally raising its leg).

Elephants and sauropods aren't completely alike, but they do have similarly-functioning legs. As such, I wouldn't be surprised if Brontomerus could do the same, only in this case, to defend itself (and for whatever it's worth, I did find this link; judging from the last four paragraphs, I have a feeling my hunch may be right).
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:iconpaleo-king:
Paleo-King Featured By Owner May 13, 2017  Professional Traditional Artist
LOL that's a funny picture. True, they can do that. And given how much smaller and less muscular the elephant's hips are, proportionally, it would be a much simpler balancing act for a sauropod.

Brontomerus was built to do a kick that went both forward and to the side, and would not have had to tilt the entire body one way to pull it off. The elephant is stiffer and has smaller muscle attachment points than a sauropod so it ends up having to to that doggy-hydrant dance to get its foot up.  Sauropods were all more hindlimb-centered than elephants and so had more of their strength in the legs (even brachiosaurs have their center of mass closer to the hips than elephants do), so they could do the kick much better, and don't forget that a sauropod's tail can be used as a prop while doing the kick, if that's needed for balance. This is probably where some of those rare rumored "tail drag prints" that Jack Horner was so fond of mentioning, came from. The tail wasn't being dragged so much as pushed into the ground for stability.
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:iconoxalaiaq:
Oxalaiaq Featured By Owner Mar 18, 2017
It was a great idea to put them side by side (kinda :P), shows the difference between both animals clearly.
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:iconowlbaskingshark:
Owlbaskingshark Featured By Owner Mar 18, 2017  Hobbyist Traditional Artist
The tol boy and the toler boy, veri famus
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:iconelsqiubbonator:
ElSqiubbonator Featured By Owner Mar 18, 2017
A question about "length". Does that account for the vertical posture of the neck, or is it what the length would be if the neck were stretched out in front of the dinosaur?
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:iconpaleo-king:
Paleo-King Featured By Owner Mar 18, 2017  Professional Traditional Artist
Length means total axial length from the snout tip to the tail tip, regardless of neck posture - so basically what you would get if the neck and the whole spine were stretched out straight.
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:iconelsqiubbonator:
ElSqiubbonator Featured By Owner Mar 18, 2017
Really? Because if the human figure there is as tall as I think he is, then these dinosaurs should be even longer than their stated length with their necks stretched out.
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:iconpaleo-king:
Paleo-King Featured By Owner Mar 18, 2017  Professional Traditional Artist
That's because sauropods are very good at optical illusions. I know, I've seen it many times :XD:

The proportions can mess with your head, the necks look longer than they are, some of it may be due to the overlapping cervical ribs creating a sense of vertigo. And brachiosaurids don't even have the most extreme neck proportions. It's hard to believe that average-sized mamenchisaurs like "Omeisaurus" tianfuensis are "only" 66 feet long when the neck proportions are so off the charts. And don't even get me started on Erketu, Daxiatitan and other euhelopodids.
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:iconnwfonseca:
nwfonseca Featured By Owner Mar 20, 2017  Professional General Artist
Yeah, that whole measurement thing can get a bit weird. I think for the lay person dinosaur lengths are kind of meaningless as it is hard to imagine how long say, 25 feet "7.62 meters" is along a curve. It is like having a snake all coiled up and telling someone it is 30 feet long yet coiled it takes up maybe 3-4 feet of space. Things really get weird with Spinosaurus etc. if we measure it exactly that way, the length is even longer. I am a designer and I do a lot of CAD drawings to build from and when we measure total length it is from one point to another in a straight line. The funny thing is, paleontologists/ biologists aren't taking measurements for artists or artisans to build from. That should definitely be a warning for people just getting into paleoart to be aware of how they are scaling. At least we have some good skeletals out there with scale bars to measure from. It takes out a bit of guess work. The nice part about working with CAD software is that it takes some of the difficulty out of measuring, for instance you can draw a line through the center of your Brachiosaurus neck and all you have to do is click on the line and look at its attributes in the attributes pallet and it tells you exactly how long the line is in metric or imperial. I don't like working in raster applications like Photoshop as you are forced to convert pixels into cm or inches and then back again. Then things get blurry at the edges. I prefer vector applications for creating detailed drawings. When I do my armatures for sculpture i either work in Illustrator or CAD software "or both" since it is far easier to measure.
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:iconpaleo-king:
Paleo-King Featured By Owner Mar 20, 2017  Professional Traditional Artist
Interesting idea! I go off of a mix of published measurements (when they can be trusted lol!) scale photos, and informal photos with either a ruler or other object for scale.

As for estimating total length after removing crushing and distortion, it's pretty much the last step... I'm old school. Just a ruler, calculator, and my 4m scale bar which has already been cross-scaled with all the bones from scaled photos and published measurements. Depending on the amount of cartilage in the joints, and how much erosion actually happened, your measurements can be as much as a half a meter off or more with these really big sauropods and it won't make much difference visually in the image.
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:iconnwfonseca:
nwfonseca Featured By Owner Mar 21, 2017  Professional General Artist
Yes, it doesn't help that there isn't a standard of measure for individual bones "not that I have seen anyway" One of the best sets of measurements I have seen were in the Parasaurolophus Ontogeny Paper by Farke, Chok, Herrero, Scolieri and Werning. Those were some of the best measurements I have seen and it is very explicit with regards to how the measurements were taken. It would be nice to have a giant set of vernier calipers to measure with.

When it comes to reconstructing crushed distorted material, or bones with missing parts. I tend to be a little bit skeptical in general of the final result. Particularly when working from 2D sources only "which is all I have". This is something I have wanted to talk about somewhere in more detail. It is just that it is hard to tell from photos how one part of a bone, say a skull articulates to multiple others in 3 dimensions. And forget about bending, I find that to be the most difficult to "fix" unless we already have an  non-distorted version to work from it is hard to tell exactly how far to unbend it. " those nasals on Sue come to mind" Not that I am disparaging anyones work, I think most of the good ones are accurate enough to have a good understanding of what the elements looked like in life. Now having access to the actual bones for the entire duration of the reconstruction would be super nice. I recently did the skull for my Giganotosaurus sculpture and even when I tried to fill in the blanks with Mupusaurus and or Tyrannotitan I found that none of the elements actually articulated well with the known elements of Giganotosaurus. also the articular surfaces of individual elements are completely gone in Giga thus making it even more difficult to articulate. You end up making an educated guess as to how elements articulate. The question then becomes, who's educated guesses are better?

I do work with paper and pencil sometimes as well, but I like being able to print at any scale I need from the cad software. That way I can change the scale with a click of a button and I don't have to redraw it or scale it on a copier. Not that I do 100% full skeletal reconstructions for an armature every time but I like to ensure the armature wire fits the skeleton as closely as possible.

One thing I love about your sauropods, is that you do dorsal and anterior views. That goes a long way toward getting proportions right. If we can only see things in one direction we can incorrectly get the sense that something is much thinner or fatter than expected.  
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:iconpaleo-king:
Paleo-King Featured By Owner Mar 21, 2017  Professional Traditional Artist
Those are all very good points. I draw the dorsal and anterior views whenever there is good photo material for them. This is not always practical, but when it is, I draw them. This way I get a better idea what shape certain families were moving in. For example it appears so far that saltasaurs didn't actually get any wider than lognkosaurs relative to torso length, but simply that they reduced the depth of the dorsal column and sometimes the rib cage too, which sometimes made them look more "tank-like" despite the width/length ratio of the torso not really increasing.

Probably crushing is the #1 reason that a lot of skeletals look weird. Most artists do not look at pictures of the bones from different angles (if the alternative pictures exist at all), they just look at one angle and draw the bones largely unchanged.

This is why so few skeletals get titanosaurs right. Titanosaurs were fat. Some of them VERY fat... it's just how the rib cage was built. The problem is, the ribs are often crushed, even in relatively complete specimens, so this is why most skeletal artists make the rib cage too narrow, they don't take into account that the ribs are crushed. So you end up with a skinny rib cage, but very wide hips, which don't match the rib cage! This is a very common error.

Some body parts like the skull are harder to reconstruct when crushed, as there are several bones and it's hard to restore the broken ones completely and see how they fit together. This is a problem with both Giganotosaurus and also the sauropods. So generally I like to keep the speculative filler to a minimum, but sometimes you have to add more because otherwise the skull doesn't make sense. For example the skull of the big Giraffatitan HMN S116 (which is not on display, Berlin Museum just used a scaled-up copy of the juvenile HMN t1 skull), is very strange. HMN S116 only makes sense with a REALLY huge nose. The nasal bone is missing, but the rear maxillary processes which support it, reach so high that the base of the nasal bone has to start much higher than in the juvenile skulls. So even if the nasal bone itself had the same proportions as the juvenile ones (it was probably taller), its base still starts much higher up on the skull, so for HMN S116 to fit together as a subadult skull, the nasal arch is something like 30% taller (relative to the snout level) than it would be if you just scaled up from t1 or another juvenile skull. A very big bulbous nose.

Luckily, that skull's individual parts like the maxilla and the braincase are not too badly crushed. They're just separated so you need to overlap them and correct for foreshortening a bit. So there wasn't much 'de-crushing' necessary. But with other incomplete skulls like that of Paluxysaurus, Ampelosaurus or Antarctosaurus, it's a MUCH harder process because some parts are really crushed and/or eroded.
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:iconasari13:
asari13 Featured By Owner Mar 18, 2017  Hobbyist Traditional Artist
awesome
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:iconthedinorocker:
thedinorocker Featured By Owner Mar 18, 2017
Excelent work, like this!
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