Rapetosaurus is Just Plain Wrong
January 31, 2013
You may remember this:
…which I used to make this:
…and then this:
The middle image is just the skeleton from the top photo cut out from the background and dropped to black using ‘Levels’ in GIMP, with the chevrons scooted up to close the gap imposed by the mounting bar.
The bottom image is the same thing tweaked a bit to repose the skeleton and get rid of some perspective distortion on the limbs. The limb posture is an attempt to reproduce an elephant step cycle from Muybridge.
That neck is wacky. Maybe not as wrong as Omeisaurus, but pretty darned wrong. As I mentioned in the previous Rapetosaurus skeleton post, the cervicals are taller than the dorsals, which is opposite the condition in every other sauropod I’ve seen. All in all, I find the reposed Rapetosaurus disturbingly horse-like. And oddly slender through the torso, dorsoventrally at least. The dorsal ribs look short in these lateral views because they’re mounted at a very odd, laterally-projecting angle that I think is probably not correct. But the ventral body profile still had to meet the distal ends of the pubes and ischia, which really can’t go anywhere without disarticulating the ilia from the sacrum (and cranking the pubes down would only force the distal ends of the ilia up, even closer to the tail–the animal still had to run its digestive and urogenital pipes through there!). So the torso was deeper than these ribs suggest, but it was still not super-deep. Contrast this with Opisthocoelicaudia, where the pubes stick down past the knees–now that was a tubby sauropod. Then again, Alamosaurus has been reconstructed with a similarly compact torso compared to its limbs–see the sketched-in ventral body profile in the skeletal recon from Lehman and Coulson (2002: figure 11).
I intend to post more photos of the mount, including some close-ups and some from different angles, and talk more about how the animal was shaped in life. And hopefully soon, because history has shown that if I don’t strike while the iron is hot, it might be a while before I get back to it. For example, I originally intended this post to follow the last Rapetosaurus skeleton post by about a week. So much for that!
Like everything else we post, these images are CC BY, so feel free to take them and use them. If you use them for the basis of anything cool, like a muscle reconstruction or life restoration, let us know and we’ll probably blog it.