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):
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.
- 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