New thunder from Down Under!
July 3, 2009
Big news today: Australia’s dinosaur fauna just got a little less depauperate. Hocknull et al. (2009) described three new saurischian dinosaurs in PLoS ONE, and two of them are sauropods! I’m just going to hit the highlights in this post. For all 51 pages of awesome, you can download the full paper for free.
Here are the new critters (Hocknull et al. 2009:fig. 40; oddly, the size of the scale bar is not given in the figure caption, but I assume it’s one meter). From top to bottom they are:
- Australovenator wintonensis, an allosauroid possibly close to Carcharodontosauridae;
- Wintonotitan wattsi, a basal titanosauriform;
- Diamantinasaurus matildae, a lithostrotian titanosaur.
The new taxa are from the late Early Cretaceous Winton Formation of eastern Australia. All three are represented by incomplete but diagnostic remains, and some of the material is really beautiful.
Here’s one of my favorite bits: the complete reconstructed manus of Diamantinasaurus (Hocknull et al. 2009:fig. 7). Sauropod forefeet were uniquely weird; for the full scoop read this. Note the thumb claw; if it’s legit–and the authors make a pretty good case that it is–then it’s unusual for a titanosaur, most of which are thought to lack hand claws and even manual phalanges.
Sadly no vertebrae were recovered with Diamantinasaurus, and those of Wintonotitan are not as pretty as the appendicular material. Still, they’re shards of excellence and they do carry some informative characters. Here are some dorsals and proximal caudals from Wintonotitan (Hocknull et al. 2009:fig. 13). You can see the partial rim of a pneumatic cavity on the dorsal in the upper left corner. According to the paper the sacrum was also pneumatic, which is to be expected in a titanosauriform.
There’s loads more to say about these critters and their implications for the evolution and biogeography of their respective clades, but tomorrow’s the 4th of July and I’ve got a barbeque to organize. Catch you on the flip side.
Hocknull SA, White MA, Tischler TR, Cook AG, Calleja ND, et al. (2009) New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE 4(7): e6190. doi:10.1371/journal.pone.0006190