Mystery of the missing Malawisaurus vertebra

Quick story: in 1993, Jacobs et al. described the basal titanosaur Malawisaurus based on reasonably complete material from, you guessed it, Malawi. This was kind of a big deal, in that Malawisaurus was at the time the most complete sauropod from the Cretaceous of Africa, and also provided important information on titanosaur skulls. Elizabeth Gomani monographed the beast in her dissertation, and the full description was published in Palaeontologica Electronica in 2005. Both relevant papers are freely available, at least as of this writing, just click on the links above or in the refs section at the end of the post.

I first saw the Malawisaurus material back in  1998 and even CT scanned some it, thanks to the generosity of Elizabeth, Lou Jacobs, and Dale Winkler. Kent Sanders and I always planned to write up the results of the CT scans with Elizabeth, but she has gone back to Malawi and according to rumor gotten involved in the government. In any case, she is out of touch. Which leaves me in the odd position of having some pretty data collected in collaboration with someone who has left the field and is currently unreachable. I'm not ready to do a full-on description of the CT results without some kind of blessing from Elizabeth, but I have decided to stop completely suppressing the info when it might do some good. Hence the pictures of the pneumatic caudal in the new paper (Wedel 2009:fig. 2).

ANYWAY–as always I intended this post to be the soul of brevity but find myself writing a small paper–something has always bothered me about Malawisaurus and I've never gotten around to either pointing it out or asking those presumably in the know (i.e., Elizabeth and Lou). Here's the deal: in the first paper, Jacobs et al. (1993:text-fig. 1) figured "No. 89-78; cervical vertebra, right lateral view" (sorry for the too-small image, it's all I could get out of the PDF):

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This vert is not figured in any of the more recent papers on Malawisaurus, including Gomani (2005). Also, it doesn't look anything like the cervicals figured by Gomani (2005:fig. 9):

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Here are some reasons why No. 89-78 can't be Malawisaurus:

• The shapes of the neural spines vary a lot down the column in Malawisaurus, but at no point do any of them look like the tall, squared-off blade of No. 89-78. In fact, I've never seen this neural spine shape in any sauropod.
• The parapophyses of Malawisaurus are long, thin plates, much like those of Sauroposeidon. This is in sharp contrast to the huge and nearly circular parapophyseal stump on No. 89-78.
• Like many titanosaurs, Malawisaurus does not have big pneumatic foramina (or "pleurocoels") on the lateral sides of the cervical centra. Instead, the centra are deeply waisted and have lots of little pneumatic foramina, again as in Sauroposeidon (hmm…I'd never given much thought to all the similarities there…). No. 89-78 doesn't seem to have anything at all on the lateral sides of the centra, at least as drawn, which is not only in stark contrast to Malawisaurus but also to every eusauropod out there.
• The centra of the Malawisaurus cervicals are proportionally very long and dorsoventrally waisted (meaning that the bottom of the centrum is arched in lateral view). The centrum of No. 89-78 is a straight, comparatively tubby cylinder.

So if No. 89-78 ain't Malawisaurus, what is it? Gomani (2005) also described the new taxon Karongasaurus based on some skull bits that aren't Malawisaurus, and No. 89-78 might belong to Karongasaurus or another, as yet undescribed sauropod. But I gotta tell ya, that vert looks like nothing else I've ever seen. The parapophysis in  particular is immense; even most Apatosaurus cervicals don't have parapophyses that massive. Throw in the apparently apneumatic centrum and the shark-fin neural spine and you've got something that I'm not even 100% sure belongs to a sauropod, although if it's not a sauropod then I don't even know where to begin. The scale bar in the Jacobs et al. figure is 50 mm, which is 5 cm or 2 inches, so the vert is more than a foot long, which pretty much rules out a non-sauropod identity. I'm lost on this one; your ideas are welcome.

Also, where the heck is No. 89-78 now, and how come nobody has mentioned it in the past 16 years? Or has it been mentioned and I just missed it? Any help here would be hot.

References

• Gomani, E.M., 2005. Sauropod dinosaurs from the Early Cretaceous of Malawi, Africa. Palaeontologia Electronica 8(1) 27A:37p.
• Jacobs, L.L., Winkler, D.A., and Downs, W.R., and Gomani, E.M. 1993. New material of an Early Cretaceous titanosaurid sauropod dinosaur from Malawi. Palaeontology 36:523-534.
• Wedel, M.J. 2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A.