This is the third post in a series on neural spine bifurcation in sauropods, inspired by Woodruff and Fowler (2012). In the first post, I looked at neural spine bifurcation in Morrison sauropod genera based on the classic monographic descriptions. In the second post, I showed that size is an unreliable criterion for assessing age and that serial variation can mimic ontogenetic change in sauropod cervicals.

The discussion over the new paper by Woodruff and Fowler (2012)–see this post and the unusually energetic comment thread that follows–made me want to go back to the literature and see what was known or could be inferred about neural spine bifurcation in the Morrison sauropods before the recent paper was published.

Since we’ve been a bit light on sauropods lately, here’s CM 11338, the juvenile Camarasaurus from Dinosaur National Monument, in Plate 15 from Gilmore’s 1925 monograph. It’s probably the nicest single sauropod skeleton ever found, and required only minor restoration and reposing for this wall mount at the Carnegie Museum of Natural History. The same thing in a fake antique finish suitable for printing at 8×10″ and framing.

Just  a quick note to let anyone who’s not on the Dinosaur Mailing List know that the DML has spawned a new list dedicated to the history of palaeontology.  It’s hosted at Google Groups, so you have the choice of subscribing to it as a mailing list or reading it as a forum.

We should have done this long ago.  Back in the early tutorials, we covered skeletal details such as regions of the vertebral column, basic vertebral anatomy, pneumaticity and laminae, but we never started out with an overview of the sauropod skeleton. Time to fix that.  This is numbered as Tutorial 15 but you can think of it as Tutorial Zero if you prefer.

In our recent paper on how the long necks of sauropods did not evolve primarily due to sexual selection (Taylor et al. 2011), one of the ideas we discussed is that sexual dimorphism between the necks of male and female sauropods would be an indicator of sexual selection.  And, rather despairingly, we wrote (page 4): But I wonder if we realise just how true this is, and how blind we are flying?

Needless to say, one of the things I love most about Paco’s Brontomerus artwork is that it’s a rare and welcome example of the much neglected Sauropods Stomping Theropods school of palaeo-art. When I reviewed the examples I know of, I was a bit disappointed to find that they number only five.  Here they are, in chronological order.

Sorry for the very short post. We have some longer stuff planned, but we’ve been too busy to kick it out this week, and I wanted to leave you with something cool to ponder over the weekend. Here’s the ilium of Giraffatitan overlaid on that of Brontomerus , scaled to the same acetabulum diameter ( Giraffatitan is HMN J1, left ilium, modified from Janensch 1961: pl. E, fig.

For reasons that will soon become apparent (yes, that’s a teaser), Matt and I wanted to figure out how heavy Camarasaurus was.  This is the story of how I almost completely badgered up part of that problem.  I am publishing it as a cautionary tale because I am very secure and don’t mind everyone knowing that I’m an idiot.

You may remember that when I wrote about Amphicoelias diplobrontobarowassea the other day, I rather ungraciously complained that “I don’t want to talk about that.