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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. 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 actually 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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:iconoxalaiaq:
Oxalaiaq Featured By Owner 5 days ago
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 5 days ago  New Deviant Hobbyist Traditional Artist
The tol boy and the toler boy, veri famus
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:iconmajestic-colossus:
Majestic-Colossus Featured By Owner 5 days ago  New Deviant
Awesome. This is not their maximum size, right?
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:iconmajestic-colossus:
Majestic-Colossus Featured By Owner 5 days ago  New Deviant
Oh, they are subadults. Sorry.
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:iconelsqiubbonator:
ElSqiubbonator Featured By Owner 5 days ago
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 5 days ago  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 5 days ago
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 5 days ago  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 3 days ago  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 3 days ago  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 2 days ago  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 2 days ago  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 5 days ago  Hobbyist Traditional Artist
awesome
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:iconthedinorocker:
thedinorocker Featured By Owner 5 days ago
Excelent work, like this!
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