This blog currently suffers (and for longer spells before has suffered) from a lack of dinosaur palaeo. Given it’s name that’s a pretty serious condition, which requires immediate treatment. So, here we go with a strong dose of dinosaur 🙂 I dug out a few more photos of the MfN dinosaurs mounts from unusual perspectives. Photos normal visitors can’t take.
Two views of Giraffatitan brancai from Tendaguru, Tanzania. It’s a great mount, but 99% of all people only get to look at it from the ground up. Lucky ones get to use ladders. I used the ladder to take photos in exactly (as far as I was able to tell) anterior and posterior views of the trunk. Which tells you that I am not posting these photos solely for your dinovoyeuristic pleasures, but have an ulterior motive. Which is to make these figures available to researchers. Not that I expect everyone to go through all my blog, but google image search does 😉
So why would a researcher be interested in such photos? First of all, although there are a ton of papers on Giraffatitan, including wonderful descriptions of the osteology, full with plates, some aspects are missing. As Mike Taylor just pointed out, all those papers still do not completely illustrate all bones (and in fact Mike had to upgrade his figure right away). So Mike has now done the job for one vertebra, and I am sure over time there will be more figures. What’s also important are photos that show the articulated skeleton, because it is very difficult to imagine the 3D fit from 2D images of individual bones. Here, you can see how they fit. And these photos allow doing Graphic Double Integration (GDI), a very neat way of estimating an animal’s volume and indirectly mass. They also allow building CAD 3D models of the living animal (though ideally, as my papers describe, you do that over a 3D digital mount), for lots of purposes, including (again) volume and thus mass estimation.
Additionally, you can obviously compare different species to each other, looking at differences in proportions of body parts. So let’s do that.
Diplodocus carnegii (cast) in not-quite-as-exactly anterior and posterior views. What’s immediately obvious is how you can look down the trunk of Diplodocus horizontally, because it is +/- horizontally arranged, whereas in Giraffatitan the long forelimbs mean the trunk is strongly inclined. Well, duh! That’s obvious in side view, too, and it doesn’t matter if you are on floor level or one storey up. What else can we see?
Look at the pic right above. We can see that the hind limbs of Diplodocus are “outside” the ribcage. Now scroll back up to Giraffatitan. See how the hind limbs are so close together that they are actually fully behind the ribcage, not displaced laterally? How Diplodocus‘ belly looks positively slender in comparison? Basically, Giraffatitan has a belly that’s blown up to an enormous width.
Obviously, this is info you can get from other views and even from the papers, but the views above make this blatantly obvious at a single glance. Next point: check the width versus height of the shoulder girdles. Obvious difference there. As obvious as the difference in the tails: that of Diplodocus simply continues the body, whereas that of Giraffatitan quickly tapers to a dinky little nothing. Look at the width of the hips and of, say, the 5th caudal vertebra, in comparison.
Now, a view from a bit further away:
This shows very nicely what a fat-arsed cow Giraffatitan is, in comparison to the Dicraeosaurus mount in front. I am not sure that the extremely narrow ribcage is unaffected by taphonomic deformation, but you can’t argue with the sacra and ilia. Again, in Dicraeosaurus the hind limbs are not fully behind the ribcage, and thus able to swing past it without too much abduction.
To round this off I now have a perfectly (well, almost) anterior view of Diplodocus, elevated roughly to the level of the Giraffatitan coracoids.