The sauropods of Star Wars

January 1, 2009

I’m sure Mike will deride this as sordid linkbait, but what the heck. I’ve been meaning to blog about the sauropods of Star Wars for a while now, and I was finally spurred into action by this comment over at TetZoo.

kraytbones-480

The first (and best) sauropod of Star Wars will be no surprise to anyone with reasonably sharp eyes and rudimentary knowledge of sauropod osteology: the Krayt dragon skeleton that C-3PO walks past on Tatooine is composed mainly of cast sauropod vertebrae.

krayt-cervicals

You can see that the monster’s cervicals have big cervical rib loops. The deeply bifurcated neural spines mean that they are either from a diplodocid or Camarasaurus. Some of them are also fairly long and low-spined, especially those close to the head, which rules out Camarasaurus. I find the purely fictional skull pretty unconvincing next to the real (cast) sauropod vertebrae.

krayt-dorsals

Moving on down the series, we see that all of the dorsals have high neural spines, some of which are deeply bifurcated, which again is consistent with diplodocids but not with Camarasaurus, whose bifurcated spines are all short (and fairly ugly).  The vertebrae also have broad transverse processes that give them a ‘t’ shape. You can see that whoever laid out the dorsals scrambled their order (perhaps deliberately) so that the deeply cleft vertebra in the middle is bordered ahead and behind by verts with little or no bifurcation of the neural spine. In articulated diplodocids, the neural spine cleft first appears in the anterior cervicals, grows larger and deeper through the rest of the neck, and then disappears around the middle of the dorsal series.

nhm-diplodocus-480

So which diplodocid is it? My vote is Diplodocus, probably a cast of the mounted Carnegie skeleton like the one shown here in London’s Natural History Museum (this particular mount turns up here at SV-POW! quite frequently). The cervical rib loops of the anterior cervicals attach near the bottoms of the centra instead of hanging far below them as in Apatosaurus. Also, you can see below that the cervical ribs loops of the posterior cervicals are narrow, as in Diplodocus, but not Apatosaurus (images of Diplodocus cervicals are from Hatcher’s 1901 monograph).

krayt-and-diplodocus-compared

The final piece of evidence for the Diplodocus ID is a closeup of part of one of the vertebrae. According to Wookieepedia (from which I stole the Ep IV screencap I’ve used throughout this post) Lucas and crew left the prop skeleton out in the desert when they were done shooting back in the 70s, and rediscovered it when they returned to Tunisia to film the Tatooine sequences for Attack of the Clones. I don’t know if the skeleton was scavenged by prop hunters before, during, or after the ATOC filming, but pieces of the skeleton turn up on movie prop sites, including the one shown here:

krayt-cervical-rib

This is a cervical rib of a sauropod, and it looks to me more like the slender ribs of Diplodocus than the massive ribs of Apatosaurus. I could be wrong about the genus, but if the bones in the movie don’t belong to Diplodocus they have to be Apatosaurus, and the balance of the evidence points to Diplodocus.

Oddly enough, Wikipedia states that, “The artificial skeleton used for the movie was left there after filming and still lies in the Tunisian desert. During filming of Attack of the Clones, the site was visited by the crew and the skeleton was still found there. The skull used resembles that of a Diplodocus, a herbivorous dinosaur related to the Apatosaur” (emphasis added). Good call, Wiki-trolls.

The “Krayt dragon” locality has been visited, and blogged about, by paleontologist and paleo-blogger Michael Ryan.

One more thing: Diplodocus and Apatosaurus both have 25 presacral vertebrae. The photo above is not crisp enough to determine precisely how many vertebrae are in the cervical+dorsal regions, but it’s more than 25. Also, none of the dinky anterior cervicals of Diplodocus are visible. So I think they must have gotten two sets of presacrals (possibly two whole columns) and used only the bigger vertebrae. I wonder what happened to the verts they didn’t use…I’d give a non-essential organ for a cast Diplodocus cervical.

That’s it for this one. There is another sauropod (sort of) in Episode IV (sort of), but I’ll wait a week before I blab about that one. I wonder if anyone will guess what it is in the meantime? Update: the reveal! (Which, okay, was not much of a reveal, since the answer was guessed by the first commenter!)

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