Sauropod Vertebra Picture of the Week

Yesterday, Matt showed you this starship from the Star Wars universe:

And asked whether it’s based on a cervical vertebra of Apatosaurus.

Absolutely it is. It can’t be just a coincidence. Matt showed a lot of useful orthogonal views of various Apatosaurus cervicals in the last post, but here’s a a nice informative oblique view which is similar (though not identical) to that of the Umbaran ship:

Apatosaurus ajax holotype YPM 1860, cervical vertebra of unspecified position but probably from around the middle of the neck, in left anterolateral view. This is the same vertebra that appears in the last three photos in Matt’s post.

(Because the vertebra photo was taken from higher up than the starfighter image, the condyle/cockpit appears lower on the vertebra. That is basically an effect of perspective rather than a difference in proportions.)

The questions for me are twofold: which Apatosaurus vertebra is it based on, and who did it?

What vertebra is it based on?

In some ways, the cervical that it most resembles is this classic: C?8 of the Apatosaurus excelsus holotype YPM 1980:

This one resembles the starfighter in the very deep cervical rob loops — deep even for Apatosaurus — and in the small, high condyle. It also resembled the ship in the absence of neural-spine metapophyses (due to breakage, not taxonomically significant variation, alas). The result of their absence is that the “upper wings” (i.e. postzygapophyseal rami) are swept up, out and back, as in the ship.

But in other respects it’s very different — notably the very elongate prezyg rami (an effect exaggerated by the breakage) and the more or less parallel trajectories of the top and bottom margins of the loop.

Another candidate would be the one that appears in the top left part of figure 7 (“the freak gallery”) from our recent neck-anatomy paper on arXiv:

This on is rather bulky for a model for the ship, but does have a less wrong shape of the cervical rib loops. And the damage that blew off both the prezygs and the metapophyses leaves the isolated “wings” on the top, just as in the ship.

I think the best model I can find for the starfighter is probably C8 of the Apatosaurus louisae holotype CM 3018, which Gilmore illustrated beautifully in his 1936 monograph but which unfortunately I only have as this bad scan:

It has good, deep cervical-rib loops; a definite bend from the fairly lateral upper part to the more ventrally inclined lateral part; a high, fairly small condyle; and a definite bulges where the parapophysis fuses with the cervical ribs, corresponding to the weapons pods of the starfighter.

And yet, and yet …

I can’t shake the feeling that I’ve seen another Apatosaurus vertebra somewhere that is a more or less perfect fit for the ship. But I can’t remember where I saw it. Come to that, I can’t think what specimen it could be from, if not one of those that Matt and I have shown in these posts.

Anyone?

Whose work is it?

The other mystery is — whose work is this design, and where did he or she get the shape from? In a comment on the last post, I said to Matt that “one can hardly help but suspect that Jarrod did it on your instruction”. (Jarrod is an old friend of Matt’s who works in digital effects for film and TV.) But  Matt insists it’s none of his doing — and I must say that if it had been in any way his work, he would have been shouting about it long before now.

So how did it happen?

Anyone know?

Update

The Umbaran Starfighter is an Apatosaurus vertebra–check out the rest of the saga:

• Was the Umbaran Starfighter from Clone Wars inspired by an Apatosaurus vertebra? (Dec. 13, 2012)
• Umbaran Starfighter vs. Apatosaurus cervical, round 3 (Dec. 16, 2012)
• Umbaran Starfighter update (Jan. 4, 2013)
• CONFIRMED: the Umbaran Starfighter is an Apatosaurus cervical (Jan. 21, 2013)