The first ever adequately illustrated vertebra of Giraffatitan
September 15, 2013
Janensch’s (1950) paper on the vertebral column of Giraffatitan (which he called Brachiosaurus brancai, wrongly as it turns out) is in many ways a superb piece of work. Together with a separate paper on the skull of Giraffatitan and other Tendaguru sauropods (Janensch 1935-6), and yet another on their limbs and girdles (Janensch 1961), it makes up one of the most comprehensive descriptions ever published of any sauropod.
But limitations of the era meant that he wasn’t able to illustrate the vertebrae to the level that we’d hope to see today — certainly nothing like the glorious job Tschopp and Matteus (2012) did on Kaatedocus. As a result, all you get is smallish black-and-white drawings like this one, of C5 of MB.R.2180 (previously known as S I):
And, perpetuating what’s rapidly becoming a bugbear of mine, there are no dorsal-view illustrations at all.
As it happens, Matt and I need a dorsal-view brachiosaur vertebra for a paper we’re working on. So I finally got my GIMP on and prepared a nice, high-resolution multiview illustration from the photos that Matt and I took back in 2008. Here it is:
As always, click through for the full-size version, which is 3781 by 2008.
We have here the same vertebra as above: MB.R.2180:C5. On the top row, the long-awaited dorsal view, with anterior to the left; on the bottom row (from left to right): anterior, left lateral and posterior views.
You’ll notice that I’ve illustrated the left side rather than the right that Janensch used. We have photos from both sides, but none of the right-side images came out as cleanly as this one. The anterior and posterior views are pleasantly familiar from Janensch’s figures — although my posterior one is evidently from a slightly more elevated aspect, hence the obscured upper parts of the transverse processes. I also note that Janensch rather sneakily restored the broken parts on both sides of the neurapophysis, and threw in some more prominent spinopostzygapophyseal lamine than the fossil really justifies.
Let’s look more closely at that crucial dorsal view:
It’s now apparent just how narrow brachiosaur cervicals are — at least, those as anterior as C5. You can also see how neatly the spinoprezygapophyseal and spinopostzygapophyseal laminae converge in an “X” shape to form the neurapophysis; and how the prezygapophyseal rami are drawn out almost to a point, with relatively small facets.
References
- Janensch, W. (1935-36). Die Schadel der Sauropoden Brachiosaurus, Barosaurus und Dicraeosaurus aus den Tendaguru-Schichten Deutsch-Ostafrikas. Palaeontographica (Suppl. 7) 2:147-298.
- Janensch, Werner. 1950. Die Wirbelsaule von Brachiosaurus brancai. Palaeontographica (Suppl. 7) 3:27-93.
- Janensch, Werner. 1961. Die Gliedmaszen und Gliedmaszengurtel der Sauropoden der Tendaguru-Schichten. Palaeontographica (Suppl. 7) 3:177-235.
- Tschopp, Emanuel, and Octávio Mateus. 2012. The skull and neck of a new flagellicaudatan sauropod from the Morrison Formation and its implication for the evolution and ontogeny of diplodocid dinosaurs. Journal of Systematic Palaeontology. doi:10.1080/14772019.2012.746589
Sauropod Vertebra Picture of the Week 
September 15, 2013 at 4:37 am
That is cool. The dorsal view especially shows a kind of “alien” form… looks kind of like abstract sculpture.
September 15, 2013 at 5:25 am
Thanks, Mike. This really does illustrate(!) how important it is to have views from all three axes to be able to appreciate the gross morphology of vertebrae (actually… pretty much anything).
From a strictly engineering perspective it would seem to make sense that a weight-bearing structure would be more robust top-bottom than side-side. Which only serves to highlight how freaking weird some Apatosaurus cervicals are. What did they do with those necks?
September 15, 2013 at 6:16 am
If I may venture a minor, pedantic quibble: I would say that this is merely the least inadequately illustrated vertebra of Giraffatitan.
On the plus side, showing the left side in addition to the right is HUGE. Especially for sauropod vertebrae, where the laminae and fossae often vary from left to right, illustrating both sides whenever possible would be extremely helpful for sorting meaningful variation. But essentially no-one does this (not even me).
On the minus side, we’re still missing the ventral surface. Now, I know that for sauropod vertebrae it can be nigh on to impossible to get good orthogonal ventral shots, because it means either standing the big heavy centrum on the fragile neural spine or at least laying the whole vert over on its side, which can be hairy proposition. But I also think that the omission of ventral views from many illustrations*–and of ventral features from many written descriptions–betrays a sort of bias or blind spot in our thinking. There is no a priori reason why the ventral surfaces of vertebrae should be any less interesting or informative than the other surfaces. I have a whole unborn paper in my head about pneumatic fossae and foramina on the ventral surfaces of sauropod vertebrae. They are definitely there in many taxa, at least in the cervicals and caudals, just rarely documented. Probably past time to fix that.
* But not all. The Lovelace et al. Supersaurus paper is a happy counterexample. That may be the only sauropod paper EVER to include a comparative illustration of vertebrae from several taxa in ventral view. If anyone knows of any others (comparative ventral views, not just ventral views), please let me know. I intend to become an irritatingly well-informed crank on this subject.
September 15, 2013 at 5:39 pm
[…] thought I’d done a decent job of illustrating MB.R.2180:C5 last time, but Wedel was not satisfied, demanding ventral and right-lateral views as well as the provided […]
September 27, 2013 at 3:08 pm
[…] 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 […]