Sauropod guru Jeff Wilson is on Twitter, as of a couple of weeks ago. In one of his earliest tweets, he showed the world this gorgeous photo of a Rebbachisaurus dorsal:

Jeff Wilson (left) and Ronan Allain (right), with dorsal vertebra of Rebbachisaurus.

Jeff Wilson (left) and Ronan Allain (right), with dorsal vertebra of Rebbachisaurus. Photograph by MNHN photographer, Copyright © Muséum National d’Histoire Natural.

I’m pretty certain this is the dorsal vertebra that’s been on exhibition in Paris for some time, and which is part of the holotype of Rebbachisaurus garasbae, which is in turn the type specimen of Rebbachisaurus and so of Rebbachisauridae as a whole. In which case it’s pretty darned important as defining a major group of sauropods.

This specimen was initially described, very briefly and without illustrations, by Lavocat (1954). The species (though a different specimen) was given a slightly better treatment by Russell (1996), as part of a larger work on isolated dinosaur bones. Russell included some line-drawings of the material (his figures 29-31), of which the pick is definitely this one of the bottom part of a dorsal vertebra:

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Rebbachisaurus garasbae, NMC 50844, anterior dorsal vertebra in (a) right lateral, (b) anterior, (c) left lateral and (d) posterior aspect. From Russell (1996:figure 30).

As noted by Russell (p388), this vertebra is similar, but not identical, to the one in Wilson’s photo. Russell says of his specimen that “the greater length of the centrum relative to the height and width of the intercentral articulations and less steeply projecting transverse processes imply that the vertebra occupied a more anterior position in the column.”

Will Rebbachisaurus ever get the detailed treatment that such gorgeous material deserves? Yes! here’s another tweet from Jeff:

Fantastic to think that Rebbachisaurus is in the works, and Nigersaurus to follow! Happy days!

References

  • Lavocat, R. 1954. Sur les Dinosauriens du continental intercalaire des Kem-Kem de la Daoura. [On the dinosaurs of the Continental Intercalaire of the Kem Kem of the Daoura].Comptes Rendus 19th Intenational Geological Congress 1952 (1):65-68. [English translation]
  • Russell, D.A. (1996). Isolated dinosaur bones from the Middle Cretaceous of the Tafilalt, Morocco. Museum Natl. d’Histoire Nat. (Paris) Bull. Ser. 4 18 (Section C, Nos. 2-3), 349-402.
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Sauroposeidon and friends

February 24, 2014

Sauroposeidon and kin cervicals - DRAFTAs a break from photography posts, here are four pretty big vertebrae that swirl in the same thought-space in my head. All are shown to scale, in right lateral view. These are not the biggest sauropod cervical vertebrae–Supersaurus beats them all, and there are vertebrae of Puertasaurus, Alamosaurus, and Futalognkosaurus that rival the big Sauroposeidon vert, but those are either less well preserved or still awaiting detailed description.

Incidentally, I think BYU 12867 is a C10. The centrum proportions are about right, compared to Giraffatitan, and the neural spine looks good, too, like a geometric transformation of the big Giraffatitan C8. Also, the drawn-in prezyg outline for MIWG.7306 is a little short; the actual prezyg is a monster and would have overhung the condyle by another 10cm or so. I’m pretty sure that we had a composite photograph showing this at one point, but irritatingly none of us can find it at the moment. If it turns up, I’ll update the image.

For a long time I thought Sauroposeidon was a brachiosaurid. Now it seems to be a somphospondyl (D’Emic 2012) or possibly even a basal titanosaur (Mannion et al. 2013), even if we stick just to the holotype. But if it’s not a brachiosaurid, it’s cervical vertebrae are at least coarsely brachiosaur-y in outline.

You  may recall from Naish et al. (2004) that MIWG.7306 shares several derived characters with the holotype vertebrae of Sauroposeidon. Does that mean that Angloposeidon is a somphospondyl or titanosaur as well? I dunno–as always, we need more material–but it’s an interesting possibility.

References

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The links in the first slide:

Mike’s post on desaturating the background in specimen photos is here, and previous posts in this series are here.

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Previous posts in this series are here.

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This whole section, including the title, is mostly swiped from Mike’s Tutorial 17.

Other posts in this series are here.

Papers referenced in these slides:

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Previous posts in this series:

Part 1: Intro and Stromer

Part 2: Taking good photos

Part 3: Backdrops and lighting

And the rest of the series is here.