Xenoposeidon comes to California
September 5, 2018
No time right now for me to dig into the interesting and important discussion on how we should orient vertebrae (here and here so far) – that will be coming soon. In the meantime, here’s something else.
As printed, in one of WesternU’s 3D printers.
Coming off the tray.
Cleaned up and in my hand. This is a 70% scale print, so a little smaller than the original, but all the important morphology is clear enough. For one thing, I can finally make sense of the dorsal views of the vertebra.
I have been astonished at how useful a 3D print can be as an aid to thought. The caudals of the Snowmass Haplocanthosaurus are among the smallest sauropod vertebrae I’ve spent a lot of time with, and they’re still heavy enough and fragile enough that I don’t just whip them out and twirl them around in my fingers. But I can do that with the 3D prints, and it really helps ram the morphology home in my brain. There are a thousand subtle things I might not otherwise have noticed if I hadn’t been able to turn those shapes over easily in my hand. Not to mention the other things you can do with prints, like physically sculpt on them without gooping up your fossils (we’re midway through step #8 from that post, BTW).
Anyway, back to Xeno. Mike reminded me that I have seen the actual specimen in person exactly once, very briefly during our 2005 visit to the NHM collections when I was over there for SVPCA. But it wasn’t Xeno yet, and we had other fish to fry, including a lot of pneumatic and possibly-pneumatic stuff for me to see and photograph for my dissertation. So I have to admit that it didn’t register. Being able to handle it now, so much that Mike has written about it snaps into focus. Not that his writing isn’t clear, there’s just a huge gulf between the best written description and holding a thing in your hands.
Why do I have this thing? Partly to educate myself, partly because it’s relevant to a current project, and partly because we may not be done with Xeno. Stay tuned.
Many thanks to Gary Wisser for setting up the print, and to Jeff Macalino for pulling it for me.
Sauropod Vertebra Picture of the Week 
September 6, 2018 at 8:11 am
My jealousy should be readily detectable, even from eight timezones away.
In the second photo, the Xeno print is sort of bone-coloured, but in the last one it’s grey all over. What’s the story there? If you painted it, I assume this is a base-coat, rather than the intended finish?
September 6, 2018 at 9:05 am
No paint, just differences in ambient light. It’s gray.
September 6, 2018 at 10:43 am
Wow, that’s some crazy-ass ambient-light difference. A warning to us all against over-interpreting fossil colour in photos.
September 6, 2018 at 8:37 pm
The gray MakerBot plastic interacts oddly with light, with mirror-bright reflections at some angles and hardly anything at others. It doesn’t photograph particularly well – or, perhaps, I just haven’t gotten good at photographing it yet.
A warning to us all against over-interpreting fossil colour in photos.
Word. It’s not that color in fossils is never useful, just that maybe 90% of the time it’s bad data – doesn’t correspond to anything biologically real or useful, and actively obscures shape by polluting it with spurious color. I believe you were the one who pointed out to me that of all the images in my Haplo caudal comparo, the photo of the actual specimen was the least informative.
And yet, not completely uninformative. For the publication of Dahalokely, Andy Farke and Joe Sertich used renders of 3D models and color photos in the same views for the 2D illustrations, as well as publishing the 3D models. I think that’s the way to go, even if it’s a little more work. I guess my upcoming papers will give me a chance to put my money where my mouth is, eh?
Reference:
Farke, A.A. and Sertich, J.J., 2013. An abelisauroid theropod dinosaur from the Turonian of Madagascar. PloS one, 8(4), p.e62047.