Christine Argot of the MNHN, Paris, drew our attention to this wonderful old photo (from here, original caption reproduced below):

© Paleontological Museum, Moscow
In the beginning of XX century, the Severo-Dvinskaya gallery (named after prof. Amalitsky) became the gold basis of the exhibition hall of ancient life in the Geological Museum of St-Petersburg. The museum hall was completed with a cast of the Diplodicus carnegii skeleton presented by E.Carnegy fund in 1913, at the 300-th anniversary of the Romanovs dynasty.

I found a different version of what seems to be the same photo (greyscaled, lower resolution, but showing more of the surrounding area) here:

What we have here is a truly bizarre mount of Diplodocus – almost certainly one of the casts of the D. carnegii holotype CM 84 — with perfectly erect, parasagittal hind-limbs, but bizarrely everted elbows.

There are a few mysteries here.

First, where and when was this photo taken? Christine’s email described this as a “picture of a Diplodocus cast taken in St. Petersburg around 1920″, and the caption above seems to confirm that location; but then why is it copyright the Paleontological Museum, Moscow? Since the web-site in question is for a Swedish museum, it’s not forthcoming.

The second photo is from the web-site of the Borisyak Paleontological Institute in Moscow, but that site unfortunately provides no caption. The juxtaposition with two more modern Diplodocus-skeleton photos that are from its own gallery perhaps suggest that the modern mount shown in the more recent photographs is a re-pose of the old mount in the black-and white photo. If so, that might mean that the skeleton was actually in Moscow all along rather than St. Petersburg, or perhaps that it was moved from St. Petersburg to Moscow and  remounted there.

Does anyone know? Has anyone out there visited the St. Petersburg museum recently and seen whether there is still a Diplodocus skeleton there? If so, is it still mounted in this bizarre way? Better yet, do you have photos?

Tornier’s sprawling, disarticulated reconstruction of Diplodocus, modified from Tornier (1909, plate II).

The second question of course is why was this posture used? This pose makes no sense for several reasons — one of which is that even if Diplodocus could attain this posture it would only serve to leave the forefeet under the torso in the same position as erect forelimbs would have them. The pose only makes any kind of sense at all if you imagine the animal lowering its torso to drink; but given that it had a flexible six-meter-long neck, that hardly seems necessary.

Of course Diplodocus does have a history of odd postures: because of the completeness of the D. carnegii holotype, it became the subject of the Sauropod Posture Wars between Tornier, Hay and Holland in the early 20th Century. Both Tornier (1909) and Hay (1910) favoured a sprawling posture like that of lizards (see images above and below), and were soundly refuted by Holland

The form and attitudes of Diplodocus. Hay (1910: plate 1)

But the Tornier and Hay postures bear no relation to that of the mounted skeleton in the photographs above: they position the forefeet far lateral to the torso, and affect the hindlimbs as well as the forelimbs. So whatever the Russian mount was doing, I don’t think it can have been intended as a representation of the Tornier/Hay hypothesis.

But it gets even weirder. Christine tells me that “I’m aware of [...] the tests that Holland performed on the Russian cast to get rid of the hypothesis suggesting a potential lizard-like posture. So I think that he would have never allowed such a posture for one of the casts he mounted himself.” Now I didn’t know that Holland had executed the mounting of this cast. Assuming that’s right, it makes it even more inexplicable that he would have allowed such a posture.

Or did he?

Christine’s email finishes by asking: “What do you think? do you think that somebody could have come behind Holland to change the position? do you know any colleague or publication who could mention this peculiar cast and comment its posture?”

Can anyone help?

References

• Hay, Oliver. P. 1910. On the manner of locomotion of the dinosaurs, especially Diplodocus, with remarks on the origin of birds. Proceedings of the Washington Academy of Sciences 12(1):1-25.
• Holland, W. J. 1910. A review of some recent criticisms of the restorations of sauropod dinosaurs existing in the museums of the United States, with special reference to that of Diplodocus carnegiei in the Carnegie museum. American Naturalist 44:259-283.
• Nieuwland, Ilja. 2010. The colossal stranger. Andrew Carnegie and Diplodocus intrude European Culture, 1904–1912. Endeavour 34(2):61-68.
• Tornier, Gustav. 1909. Wie war der Diplodocus carnegii wirklich gebaut? Sitzungsbericht der Gesellschaft naturforschender Freunde zu Berlin 4:193– 209.