I would love to know more about their range of motion in life – did these animals kneel or lay down sometimes, or were they basically on their feet for life? How straight, and how vertical, did they normally keep their limbs? How readily could they turn?

Or …back on the topic of vertebrae!… how did those necks behave?

All this is of more than usual interest to me just now, as I am considering the practicability of sauropods going on parade locally in August: for Dunfermline’s inaugural Carnegie Festival of the Imagination.

Diplodocus carnegii and Apatosaurus louisae, being named after Andrew Carnegie and his wife Louise, and now approximately centenary, seem apt subjects for a festival here in his home city…

…if a mite challenging…

I suspect any parade versions may have to be rather more pneumatic than the originals!

A sphere has the advantage of looking the same whatever the viewing angle. Its diameter is thus easily compared for scaling of the object.

Any pictures with Daleks in are handy for scaling nearby objects… all those 4inch domes…

I mention all this only to suggest that this might be a part, if not the entirety, of the difference between reported measurements and measurements taken from photos with a scale bar. And, of course, if one uses something like Photoshop to replace the actual scale bar with a solid black or white bar instead, an additional error (albeit again probably small but measureable) is introduced by trying to approximate which column or row of pixels really equals the end of the mark on the scale bar and should therefore also be the end of the digital “replacement” bar…

The seeming gracility of the Mamenchisaurus hochuanensis humeri and femora, and the seeming robustness of its cervicals, are both illusions.

In most sauropods, M.hoch included, humeri and femora are both anterolaterally compressed, so that their transverse width is about twice their anteroposterior width. Take a look at the photo at http://www.miketaylor.org.uk/dino/mamenchi/page/16.html , which is of another cast of precisely the same specimen of M.hoch. From this anterolateral perspective, the humeri look very robust.

The cervicals look robust from the side for several reason. First, they are noticably taller than they are wide, so the same neck looked at from above would appear a lot thinner. Second, crushing in this particular specimen exaggerates the degree of eccentricity to make the cervicals look even taller than they were in life. Third, although they encompassed a lot of space, they were very lightly constructed and largely filled with air — whereas in this specimen all the air-spaces are filled with matrix, making them appear solid.

So the legs are much more solid, and the neck much less so, than you’d think from the photo above.

By the way, the FMNH staff were fantastically helpful when we visited — I’ve never known anything like it. They brought that cherry-picker thing into the museum just for us, so I could get up close and personal with the cervicals. They also disassembled a huge display cabinet so we could get at the Brachiosaurus altithorax type humerus. Happy days. Not only that, in a sushi restaurant just across the park from the museum, we ordered a Gozilla Roll, which may be the single most wondrous thing I have ever tasted.

‘Abrosaurus has 13 cervicals, rather than 19 like M. hochuanensis, and its cervicals are only about a third longer than its dorsals.. If Hudiesaurus was built like a giant Abrosaurus, it might have approximated a large individual of Camarasaurus in both body size and neck length.. Also, assigning serial positions to isolated vertebrae is tough..’

It’s interesting to consider that partial remains may leave much scope for such variant reconstructions. And that new incomplete finds may not have had the same proportions as species already known.. even those species judged to be most similar on the basis of particular (equivalent?) bones.

Re that photo of M. hochuanensis, it may be a naive comment but am I alone in thinking how flimsy the leg bones look compared to the neck? (especially those last few cervicals.. pleurocoels there I know, but still awesome). Femur and humerus in particular seem mere sticks by comparison!

It makes me wonder how these creatures could manage to squat, kneel or lie down – let alone mate! – and how slowly they may have moved… it’s not just their weight, it’s the inertia and angular momentum, torque and leverage, that I’m thinking of.

Thanks for the interesting reading!