Mystery sauropod dorsals of the Wealden, part 1: BMNH R2523
October 4, 2007
Just a quick post to feed the desire for sheer sauropodous beauty. This picture shows a single partial vertebra in six different views. The top row, from left to right, shows the vertebra in left lateral view (i.e. the front is pointing to the left as you look at it), then in an oblique view, then in anterior view (i.e. from the front). The bottom row shows it in right lateral, oblique, and posterior (i.e. from the back).
This is a dorsal vertebra (i.e. from the back rather than the neck, hips or tail – see Matt’s “Regions of the vertebral column” tutorial. It’s probably from quite far back in the dorsal column, near the hips.
What kind of sauropod is it? I’m not sure. At first, I thought it was rather Camarasaurus-like, which would be an exciting result because there is no convincing camarasaurid material known from the Wealden. But then when I put it into a cladistic analysis, it popped out as a basal diplodocoid, though very weakly supported. I have a lot more work lined up to do on Wealden sauropod dorsals, so hopefully I’ll be able to get back to you with a firmer identification at some point.
What is this Wealden, I hear you ask? It’s a big chunk of rock from the Early Cretaceous, extending across much of southern England and into the continent. Darren is a real Weald Jockey, so I’ll leave it to him to tell you more about it in a future post (or, more likely to point you to one of the Wealden posts on his Tetrapod Zoology blog).
October 4, 2007 at 3:18 pm
Mike: in the right lateral and oblique views, what are those whitish things in what looks like a window into the top part of the centrum? Are they artifacts of preparation? I’m referring to the parallel things that look a bit like short piano keys.
October 4, 2007 at 3:49 pm
Ha ha, beat you to it, Mike (Taylor).
Mike from Ottawa: those whitish things that look like windows ARE windows. Perhaps the coolest thing about sauropod vertebrae, and something we haven’t gotten around to discussing properly yet, is that in most sauropods the cervical and dorsal vertebrae were pneumatic–i.e., filled with air, just like the bones of birds. If you go back to the regions of the vertebral column tutorial, you can see that the Apatosaurus vertebra is so shot full of holes it looks like 50 Cent. Those holes, and the windows in this vert, are how the air got in. Stay tuned for more hot pneumatic vertebra action…
October 4, 2007 at 3:59 pm
It is true, though, that this vertebra does have a particularly weird and regular pattern on laminae within the fossa. I don’t recall seeing such a pronounced “piano keys” effect anywhere else, do you?
October 4, 2007 at 4:05 pm
I haven’t seen it elsewhere. Looks very odd.
October 4, 2007 at 7:21 pm
A tribute, though, to the depths that might be found in ‘just’ sauropod vertebrae.
I have to admit, I don’t find sauropods interesting with their skin and muscles on in reconstructions, but the kind of explanations of what is going on inside that you guys and especially Darren (since I’ve been reading TZ for quite a while now) provide makes them much more interesting inside and in their mechanics.
October 4, 2007 at 11:08 pm
[…] Dorsal to the centrum is the neural arch, which is surmounted by the neural spine. A hollow passageway runs through the neural arch from front to back: this houses the spinal cord, and is called the neural canal. (You can’t really see it in the pictures above; you can make it out much more clearly in the BMNH R2523 photos, anterior and posterior.) […]
October 28, 2007 at 12:19 am
[…] with the wonder that is BMNH R2523, I don’t know what R90a is yet. A preliminary cladistic analysis indicates that it is a […]
January 23, 2008 at 10:06 pm
awesome
July 12, 2009 at 9:21 pm
[…] Supergroup of southern England includes more than its fair share of enigmatic sauropod remains (see Mystery sauropod dorsals of the Wealden part 1, part 2, part 3). Poor taxonomic decisions, a dearth of adequate descriptive literature, a lack of […]
September 14, 2013 at 1:44 pm
[…] you’re working on a Wealden sauropod — for example, the disturbingly Camarasaurus-like isolated dorsal vertebra NHM R2523 — and for some reason you desperately want to publish your work in Cretaceous […]
June 3, 2015 at 6:07 pm
[…] on and off, since the early 1990s. Then in the late 2000s, when I was working on Xenoposeidon and other Wealden sauropods, I started work independently on a redescription — which of course is why I […]