Sauroposeidon in 3D

April 18, 2014

Sauroposeidon meet Sauroposeidon

I was in Oklahoma and Texas last week, seeing Sauroposeidon, Paluxysaurus, Astrophocaudia, and Alamosaurus, at the Sam Noble Oklahoma Museum of Natural History, the Fort Worth Museum of Science and History, the Shuler Museum of Paleontology at SMU, and the Perot Museum of Nature and Science, respectively. I have a ton of interesting things from that trip that I could blog about, but unfortunately I have no time. Ten days from now, I’m off to Colorado and Utah for the Mid-Mesozoic conference and field trip, and between now and then I need to finish up my bits on three collaborative papers, get my summer anatomy lectures posted for internal peer review here at WesternU, and–oh yeah–actually write my conference talk. Fun times.

BUT after being subjected to the horror of the Yale Brontosaurus skull, I figured you all deserved a little awesome.

Photographing Sauroposeidon 2014-04-07

So here’s me getting one of 351 photos of the most posterior and largest of the Sauroposeidon jackets (this is not the awesome, BTW, just a stop along the way). This jacket holds what I once inferred to be the back half of C7 and all of C8. Now that Sauroposeidon may be a somphospondyl rather than a brachiosaur, who knows what verts these are–basal somphospondyls have up to 17 cervicals to brachiosaurids’ probable 13 (for a hypothetical view of an even-longer-necked Sauroposeidon, see this probably-prophetic post by Mike). The vertically-mounted skeleton in the background is Cotylorhynchus. Cotylorhynchus got a lot bigger than that–up to maybe 6 meters long and 2 or 3 tons–and was probably the largest land animal that had ever existed back in the Early Permian. Photo by OU grad student Andrew Thomas, whom you’ll be hearing about more here in the future.

I couldn’t crank the model myself on the road, thanks to the pathetic lack of processing power in my 6-year-old laptop (which will be replaced RSN). Andy Farke volunteered to do the photogrammetricizing with Agisoft Photoscan, if only I’d DropBox him the pictures. Here’s a screenshot from MeshLab showing the result:

Sauroposeidon lateral PLY 10 - 6 and 9 blended

And my best taken-from-overhead quasi-lateral photograph:

Sauroposeidon C8 jacket lateral photo 2014-04-07

If you’re curious, the meter stick at the top is actually one meter long, it just has the English measurement side showing. The giant caliper at the bottom is also marked off in inches, and it is open to 36.0 inches (it didn’t go to 1 meter, or I would have used that). You can tell that there is some perspective distortion involved here since 36 inches on the caliper is 1380 pixels, whereas the 39.4-inch meter stick is only 1341 pixels. Man, I hate scale bars. But they make good calibration targets.

Incidentally, after playing around with the model in orthographic mode in MeshLab, the distortions in the photos of the vertebrae themselves just scream at me. Finally, finally, I can escape the tyranny of perspective. Compare the ends of the big wooden beam at the top of the jacket to get a feel for how much the two views differ.

Working on Sauroposeidon again after all this time made me seriously nostalgic. I love that beast. I don’t think I’m exaggerating when I say that those vertebrae are the most gorgeous physical objects in the universe. Also, an appropriately huge thank-you to preparator Kyle Davies (of apatosaur-sculpting fame), collections manager Jen Larsen, and Andrew Thomas again for help with wrassling those verts around, and for sharing their thoughts and advice. Thanks also to curators Rich Cifelli and Nick Czaplewski for their hospitality and for the go-ahead to undertake this work, and to Andy Farke for generating the model.

I’ll have a lot more to say about this stuff in the future. I didn’t go to all this work just for giggles. For a long time I’ve had a hankering to do a paper on the detailed anatomy of Sauroposeidon, based on all of the things that I’ve noticed in the last decade that didn’t make it into any of the early papers. And now there’s the proposed synonymy of Paluxysaurus with Sauroposeidon. And “Angloposeidon” needs some attention–Darren and I have been thinking about writing “Angloposeidon II” for years now. And…well, plenty more.

So, loads more to come, but not for the next few weeks. Eventually I’ll be publishing all of this–the photos, the 3D models, the whole works. Stay tuned.

UPDATE a few days later

Man, I am frazzled, because I forgot to include the moral of the story: if I can do this, you can do this. There are good, free photogrammetry programs out there–Peter Falkingham published a  whole paper on free photogrammetry in 2012, and posted a guide to an even better program, VisualSFM, on Academia.edu. Even Agisoft Photoscan is not prohibitively expensive–under $200 for an educational license. MeshLab is free and has hordes of good free tutorials. For the photography itself, you basically just build a virtual dome of photos around an object. If you need more instructions than that, Heinrich has written a whole series of tutorials. It doesn’t take a fancy camera–I used a point-and-shoot for the Sauroposeidon work shown here (a Canon S100 operating at 6 megapixels, if anyone is curious). What are you waiting for?

Illustration talk slide 58

Illustration talk slide 59

Illustration talk slide 60

The rest of the series.

References

Aitor Ederra drew my attention to this painting by Frederik Spindler:

86e63b799a

It’s briefly discussed in a blog-post on changing norms in palaeo-art. (I think the blog is Spindler’s, but I can’t find confirmation — its About page is singularly uninformative.)

As so often when we look at All Yesterdays-style palaeo-art, the initial reaction is “no way!”, but that’s quickly followed by a more thoughtful “… but why not?”

Well, why not? We have bare-skinned African and Asian elephants, but not so long ago we had wooly mammoths. Even assuming that Giraffatitan was as naked as Loxodonta, why would its polar equivalents not have adapted the ancestral dinofuzz into a thick insulating coat?

 

Illustration talk slide 47

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That last one really hurts. Here’s the original image, which should have gone in the paper with the interpretive trace next to it rather than on top of it:

Sauroposeidon C6-C7 scout

The rest of the series.

Papers referenced in these slides:

Illustration talk slide 44

Illustration talk slide 45

Illustration talk slide 46

On that last slide, I also talked about two further elaborations: figures that take up the entire page, with the caption on a separate (usually facing) page, and side title figures, which are wider than tall and get turned on their sides to better use the space on the page.

Also, if I was doing this over I’d amend the statement on the last slide with, “but it doesn’t hurt you at all to be cognizant of these things, partly because they’re easy, and partly because your paper may end up at an outlet you didn’t anticipate when you wrote it.”

And I just noticed that the first slide in this group has the word ‘without’ duplicated. Jeez, what a maroon. I’ll try to remember to fix that before I post the whole slide set at the end of this exercise.

A final point: because I am picking illustrations from my whole career to illustrate these various points, almost all fail in some obvious way. The photos from the second slide should be in color, for example. When I actually gave this talk, I passed out reprints of several of my papers and said, “I am certain that every single figure I have ever made could be improved. So as you look through these papers, be thinking about how each one could be made better.”

Previous posts in this series.

References

Although it would be nice to think that our site views have octupled in the last day because of Mike’s fine and funny posts about what search terms bring people to SV-POW!, the real reason is that we were blessed by incoming links from both pages of this Cracked.com article.

Now, as any person who has ever accomplished anything whatsoever knows, it is super-important to avoid Cracked.com or you’ll still be up 23 hours from now reading, “6 Mind-Blowing Ways that Comedy Writers are Secretly Destroying Your Productivity”. (I’m kidding, that article doesn’t really exist–but if it did, I’m sure it would consist entirely of descriptions and links to six other Cracked articles). But that’s only true because most of the articles there hit the sweet spot at the intersection of funny, surprisingly informative, mercifully short, and well-written. Crack.com would be a more honest URL, but I assume it was taken.

Anyway, I’d like to return the favor, so here’s a list of the 6 SV-POW! Posts Most Likely to Blow the Minds of Cracked.com Readers. If I missed some goodies or recommended some stinkers, let me know–the comment thread is open.

Amphicoelias vert reconstruction by Mike

1.How big was Amphicoelias fragillimus? I mean, really?

Who doesn’t want to read about the bizarre real-world mystery surrounding what might have been the world’s largest dinosaur? If you’re not sold, consider that the picture above shows a single vertebra that was–or at least might have been–seven and a half feet tall.

long nerves of sauropods

2. Oblivious sauropods being eaten

The mercifully short version of this much longer post, in which I consider the consequences of the world’s largest animals having the world’s longest cells.

krayt-cervicals

3. The sauropods of Star Wars

Weapons-grade anatomical pedantry.

Umbaran starfighters

4. CONFIRMED: the Umbaran Starfighter is an Apatosaurus cervical

Yes, there is a ship in Star Wars: The Clone Wars that is basically a flying dinosaur vertebra. It took us about five weeks to unravel that story–the post linked above has links to the rest of the saga.

blue-whale-and-brachiosaurus

5. SV-POW! showdown: sauropods vs whales

Our original linkbait post. Don’t miss the shorter follow-up with more critters.

Is that your flexor tubercle, Saurophaganax, or are you just hungry to see me?

Is that your flexor tubercle, Saurophaganax, or are you just hungry to see me?

6. Friday phalanges: Megaraptor vs Saurophaganax

A deliberately goofy post in which I wax poetic about the largest predatory dinosaur claws ever discovered.

So, that was a big pile of superlatives and Star Wars. If you’re hungry for more substantial fare, you might start with our Tutorials page or our Things to Make and Do series on dissecting and skeletonizing modern animals. We also blog a lot about the evils of obstructive publishers and the need for open access to the scientific literature–you can find those posts on our Shiny Digital Future page.

flaming-vagabond-in-firefly-niska-station

A parting shot in my desperate quest for attention: this Star Wars ship flying around in the background in Firefly and Serenity is at least partly my fault–full story here. Oh, and my co-blogger Mike Taylor has written an insightful and affordable book about Doctor Who; read about it here.

Illustration talk slide 39

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Illustration talk slide 43

The Sauroposeidon stuff is cribbed from this post. For the pros and cons of scale bars in figures, see the comment thread after this post. MYDD is, of course, a thing now.

Previous posts in this series.

Reference:

Wedel, M.J., and Taylor, M.P. 2013. Neural spine bifurcation in sauropod dinosaurs of the Morrison Formation: ontogenetic and phylogenetic implications. Palarch’s Journal of Vertebrate Palaeontology 10(1): 1-34. ISSN 1567-2158.

Sauroposeidon and friends

February 24, 2014

Sauroposeidon and kin cervicals - DRAFTAs a break from photography posts, here are four pretty big vertebrae that swirl in the same thought-space in my head. All are shown to scale, in right lateral view. These are not the biggest sauropod cervical vertebrae–Supersaurus beats them all, and there are vertebrae of Puertasaurus, Alamosaurus, and Futalognkosaurus that rival the big Sauroposeidon vert, but those are either less well preserved or still awaiting detailed description.

Incidentally, I think BYU 12867 is a C10. The centrum proportions are about right, compared to Giraffatitan, and the neural spine looks good, too, like a geometric transformation of the big Giraffatitan C8. Also, the drawn-in prezyg outline for MIWG.7306 is a little short; the actual prezyg is a monster and would have overhung the condyle by another 10cm or so. I’m pretty sure that we had a composite photograph showing this at one point, but irritatingly none of us can find it at the moment. If it turns up, I’ll update the image.

For a long time I thought Sauroposeidon was a brachiosaurid. Now it seems to be a somphospondyl (D’Emic 2012) or possibly even a basal titanosaur (Mannion et al. 2013), even if we stick just to the holotype. But if it’s not a brachiosaurid, it’s cervical vertebrae are at least coarsely brachiosaur-y in outline.

You  may recall from Naish et al. (2004) that MIWG.7306 shares several derived characters with the holotype vertebrae of Sauroposeidon. Does that mean that Angloposeidon is a somphospondyl or titanosaur as well? I dunno–as always, we need more material–but it’s an interesting possibility.

References

Illustration talk slide 32

Illustration talk slide 33

Illustration talk slide 34

The links in the first slide:

Mike’s post on desaturating the background in specimen photos is here, and previous posts in this series are here.

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This whole section, including the title, is mostly swiped from Mike’s Tutorial 17.

Other posts in this series are here.

Papers referenced in these slides:

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