Sauropod Vertebra Picture of the Week

Seeing the photograph in the last post of the Mamenchisaurus hochuanensis cast at the Field Museum in Chicago reminded me of a picture I’ve been meaning to post for a while. M.hoch, as I like to call it (we’re on familiar terms) is known primarily from its type specimen CCG V 20401, which was nicely described and figured by Young and Zhao in 1972. There are several pretty good quality casts of this specimen around the world: I first saw one in the car-park of the Copenhagen Geological Museum, and Chicago was the third time I saw it (and by far the best due to the excellent sight-lines from the balcony, lighting and help from the museum staff) .

The second time I saw a cast of this specimen it was actually the same one that I’d seen in Copenhagen: it was owned by the Homogea Museum in Trzic, Slovenia, and its loan to Copenhagen had expired. By happy coincidence my day-job took me to Slovenia, only 40 km or so from Trzic, so on a spare day I took a taxi to the museum where I was shown to the M.hoch cast.

Remember that bit in The Hitch-Hiker’s Guide to the Galaxy where Arthur Dent is told that the plans for demolishing his house have been on display at the council office for six months? In fact, let me quote:

“The notice was posted at the office, sir.”
“Your ‘office’ was in a basement. I had to look all over the building just to find it.”
“That’s where the office is located!”
“It was dark.”
“The lights were out!”
“So were the stairs.”
“But still, you found the notice, sir?”
“Oh, yes. It was quite ‘clearly’ posted in a locked filing cabinet in a disused lavatory with a sign on the door saying ‘Beware of the leopard.'”

That’s how I felt when I saw the Mamenchisaurus cast:

Yes, it’s in a basement. Yes, the lights were out (though, to be fair, the stairs were not). Yes, the basement is flooded (a trick that Douglas Adams missed) and for good measure the light you can see there, a portable floodlight, is powered by an extension lead that runs through the flooding. However, they didn’t have a filing cabinet big enough, so it was at least on display in the basement.

The good news is that I was able, from bits and pieces in the corner of the basement, to assemble a scaffold from which I could view the elevated cervicals:

As you can see, it consists of a trolley frame with a piece of decomposing and warped chipboard on top, surmounted by a stepladder. Unfortunately, this is a pretty tall dinosaur and those cervicals are a good 4 m off the ground, so the only way I could see the dorsal surface was by perching right on the top rung of the ladder. I do have photographic evidence, taken by a workman who was doing something mysterious in the corner of the basement, although it’s not great quality — about as good as the typical Loch Ness Monster photo:

Yes, that’s me, risking life and limb in the cause of sauropod vertebrae.

Sadly the result of all this was not very useful: the very poor lighting meant that the photos I took are low on detail, difficult to interpret, and of little scientific value. On the positive side, it was later that same month that I was in Chicago to see the better cast of the same animal, so I got all the photos I needed in the end.

Reference

• Young, C.C., and Zhao, X.-J. 1972. Mamenchisaurus hochuanensis sp. nov. Institute of Vertebrate Paleontology and Paleoanthropology Monographs, A, 8:1-30.