Today’s image comes courtesy of Phil Mannion and something he sent me for his guest post a while back on sauropod diversity. It never got used and has been sat in my files till I cam across it of late and decided to drag it out and give it an airing. It shows off the bizarre South American sauropod Amargasaurus.
This is, justifiably, famous for its groovy spines that extend as a pair of rows along the neck. This calls to mind, if on a smaller scale and rather different form, other ‘crested’ dinosaurs like Ouranosaurus. Much as I do like these, it’s also well worth talking about the fact that this is also one of a rather rare group of sauropods called dicraeosaurids. These are rather few and far between with Amargasaurus and Brachytrachelopan from South America and the eponymous Dicraeosaurus from Tanzania. All three have rather tall and oddly shaped necked vertebrae though obviously this one takes the crown, but more interestingly, they all have very short necks and are relatively small taxa.
Short (or at least relatively short) necked sauropods are turning up in increasing numbers though they’re still somewhat rare and the classic body plan of sauropods of a big body with a long neck and tail is hardly in danger, even if the dicraeosaurs are doing their best to challenge this. Long necks have an especially important place in sauropod evolution of course, and I’ll be writing more about that in the next couple of weeks. Stay tuned!


That mount has truly extraordinarily broad shoulders (and, it seems, short forelimbs, though that is probably just a visual consequence of the shoulder-mounting). Really makes me appreciate the Humboldt Museum’s dicraeosaur mount: http://svpow.wordpress.com/2008/12/21/shedloads-of-awesome-part-3-dicraeosaurus/
… or could it be that there really is evidence for unusually broad shoulders in Amargasaurus?
I thought it looked a bit broad, but then not having seen the mount for real, or the bones, I don’t really feel qualified to comment.
Should add that this is a cast, mounted in the Ernesto Bachmann Museum in Villa El Chocón (Neuquén, Argentina).
Also, Suuwassea (from the Late Jurassic Morrison Formation, North America) should now be included in the roll call of dicraeosaurids (see Salgado et al. 2006; Whitlock 2011).
Thanks for that extra info on the cast Phil. And Suuwassea? I’d totally missed that! Time for a quick re-read…
It’s real name is Amargasaurus.
I am 11 and want to be a paleantologist