Sauropod Vertebra Picture of the Week

CM 879 caudal 1 in anterior view

Here’s caudal 1 in Haplocanthosaurus priscus, CM 879. Hatcher (1903) only illustrated this vert in right lateral view, in a drawing by Sydney Prentice (see this post). I showed the vert in left lateral, right lateral, and dorsal views in my 2009 air sac paper (figs. 7 and 9, here). As far as I know, no-one has ever illustrated this vert in anterior or posterior view before.

CM 879 caudal 1 in posterior view

That’s a shame, because it’s the only first caudal of Haplocanthosaurus with a combination of good preservation and accessibility. The first caudal of the holotype, CM 572, was pretty wrecked and the drawings of it in Hatcher (1903) are largely reconstructions (this is discussed in McIntosh and Williams 1988). H. delfsi, CMNH 10380, has a nice caudal 1 but it’s stuck way up in the air in the mounted skeleton in Cleveland. The Snowmass Haplo, MWC 8028, includes a probable first caudal but it’s not going to win any beauty contests:

MWC 8028 probable caudal 1 in anterior (left), posterior (middle), and right lateral (right) views. From Foster and Wedel (2014: fig. 5).

Oh, and there’s the Bilbey haplocanthosaur on display at the Utah Field House of Natural History State Park Museum in Vernal. It has a very nice caudal sequence, probably the best for any haplocanthosaur, but (1) the specimen is under study by others so I don’t want to say too much about it, and (2) I couldn’t if I wanted to because the caudals are displayed in such a way that only the centra are easily visible.

I intended to talk a bit about the morphology of the first caudal in CM 879 and the other Haplo specimens, but now I’m out of time, so I’ll have to circle back to that in the future.

References

• Foster, J.R., and Wedel, M.J. 2014. Haplocanthosaurus (Saurischia: Sauropoda) from the lower Morrison Formation (Upper Jurassic) near Snowmass, Colorado. Volumina Jurassica 12(2): 197–210. DOI: 10.5604/17313708 .1130144
• Hatcher, J.B. 1903. Osteology of Haplocanthosaurus with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds; additional remarks on Diplodocus. Memoirs of the Carnegie Museum 2:1-75.
• McIntosh, J.S., and Williams, M. E. 1988. A new species of sauropod dinosaur, Haplocanthosaurus delfsi sp. nov., form the Upper Jurassic Morrison Fm. of Colorado. Kirtlandia 43:3-26.
• Wedel, M.J. 2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A:611-628.