Accidental anaglyphs

October 16, 2020

Everyone knows that the very first thing you should do to improve your specimen photography is to use a tripod: it eliminates hand-shake and gives you much crisper photos. In most respects, my photographs have got much, much better since I’ve been habitually using a tripod.

But it has meant I’ve not been able to benefit from happy accidents like the one that gave me this 3D anaglyph of the Archbishop‘s Cervical S in dorsal view:

(Do you have red-cyan glasses? Yes? Good! You will be able to appreciate all the delicious morphological information in this photo. No? Go and order some right now — they cost literally a dollar.)

The reason I was able to make this very useful image is because back in the old pre-tripod days I would sometimes accidentally move a little bit between taking two more-or-less identical photographs. Here are the two images that I was able to composite into the anaglyph above:

Each of them is pretty uninformative alone: who can tell one nondescript area of brown bone from another? But when combined, they are extraordinarily more informative. If you don’t have 3D glasses then (A) get some! and (B) you can get some idea of how helpful the 3D information is from the crude wigglegram below, which simply switches back and forth between the two images.

And I can’t overstate how enormously helpful I have found these accidentally sourced anaglyphs as I write the descriptive part of the Archbishop manuscript. Even at this level of crudity, they have shown me several important points of morphology that I would certainly have missed if I’d been working only from my orthogonal-view photos, and saved me from more than one misinterpretation.

The moral is twofold:

  1. When taking specimen photographs, use a tripod — but deliberately get some pairs of shots where the camera is moved to the side by about 7 cm (the distance between the pupils in an average human).
  2. If you don’t have any red-cyan glasses, get some!

I can’t even count how many sauropod vertebra pictures we’ve posted here across the last ten years, but I am confident that the total comes to at least a lot. Here’s a picture from each year of the blog’s existence so far — let’s vote on which is the best!

November 15, 2007: Xenoposeidon week, day 1: Introducing Xeno

The stark beauty of the Xenoposeidon proneneukos holotype NHMUK R2095, a mid-to-posterior partial dorsal vertebra in left and right lateral views.

February 1, 2008: Your neck is pathetic

Sauroposeidon proteles holotype OMNH 53062, 8th cervical vertebra in left lateral view (1400 mm total length). Entire human neck for scale.

January 7, 2009: The sauropods of Star Wars: Special Edition

Our old friend Giraffatitan brancai MB.R.2181 once more, this time with Matt for scale.

February 12, 2010: Tutorial 8: how to photograph big bones

The Archbishop in all its glory. The much-loved dorsals 8 and 9, in right lateral view, of the Tendaguru brachiosaurid NHMUK R5937.

May 16, 2011: Why the long necks? Probably not sexual selection

Taylor et al. (2011), fig. 1: Sauropod necks, showing relationships for a selection of species, and the range of necks lengths and morphologies that they encompass. Phylogeny based on that of Upchurch et al. (2004: fig. 13.18). Mamenchisaurus hochuanensis (neck 9.5 m long) modified from Young & Zhao (1972: fig. 4); Dicraeosaurus hansemanni (2.7 m) modified from Janensch (1936: plate XVI); Diplodocus carnegii (6.5 m) modified from Hatcher (1903: plate VI); Apatosaurus louisae (6 m) modified from Lovelace, Hartman & Wahl (2008: fig. 7); Camarasaurus supremus (5.25 m) modified from Osborn & Mook (1921: plate 84); Giraffatitan brancai (8.75 m) modified from Janensch (1950: plate VIII); giraffe (1.8 m) modified from Lydekker (1894:332). Alternating grey and white vertical bars mark 1 m increments.

April 15, 2012: Neural spine bifurcation in sauropods, Part 6: more reasons why Haplocanthosaurus is not a juvenile of a known diplodocid

Wedel 2009: Fig. 6. Pneumatization of the presacral vertebrae in Haplocanthosaurus. (A) X-ray image of a posterior cervical vertebra of CM 879 in right lateral view. (B) A CT slice through the same vertebra. (C) X-ray image of an anterior dorsal vertebra of CM 572 in left lateral view. (D) X-ray image of the same vertebra in anterior view.

January 16, 2013: Plateosaurus is pathetic

Our old friend C8 of the Giraffatitan brancai paralectotype MB.R.2181 in left dorsolateral view, with a comparable cervical of the prosauropod Plateosaurus for scale.

February 12, 2014: Can PeerJ really be only a year old?

Barosaurus lentus holotype YPM 429, Vertebra Q (C?13). Top row: left ventrolateral view. Middle row, from left to right: anterior view, with ventral to the right; ventral view; posterior view, with ventral to the left. Bottom row: right lateral view, inverted. Inset shows diapophyseal facet on right side of vertebra, indicating that the cervical ribs were unfused in this individual despite its great size. Note the broad, flat prezygapophyseal facet visible in anterior view. (Taylor and Wedel 2013b: figure 6)

September 14, 2015: So what were apatosaurs doing with their crazy necks?

A slide from our 295 SVPCA talk, illustrating key points in apatosaurine neck morphology that led us to the BRONTOSMASH hypothesis.

May 18, 2016: Thank you to all our Sauropocalypse hosts!

Mike compares Jensen’s sculpture of the big Supersaurus cervical BYU 9024 with the actual fossil.

August 15, 2017: “Biconcavoposeidon”

AMNH FARB 291, five consecutive posterior dorsal vertebrae of a probably brachiosaurid sauropod which we informally designate “Biconcavoposeidon”, in right lateral view.

(Yes, there are eleven pictures: we’ve been running for ten years, but that includes both the end of 2007 and the start of 2017.)

So, which is the picture of the decade? Vote here (and let us know in the comments if we missed your favourite).

 

As I was clearing out some clutter, I came across this hand-written list of projects that I wanted to get completed:

old-poop

Sadly, I didn’t put a date on the list. But I can estimate it as before 2013 (because of the reference of Why giraffes have short necks as a project still to be completed) but after 2011 (because the no necks for sex project is not listed.) So it’s probably from 2012, which means four years have passed since I wrote that list.

What have I achieved in that time? Not nearly enough.

  • ICZN checklist refers to the short set of name-a-new-animal instructions that I was crowdsourcing here on SV-POW!. We started this on 10 February 2011, had it nearly done less than two weeks later, then … stalled for no reason at all. Eighteen months later, the ICZN changed to allow electronic publication, instantly rendering the in-progress document obsolete. Now I don’t know whether to kill the project or update it. Should have just published it in 2011.
  • WTH (Why giraffes have short necks) was published in PeerJ, hurrah!
  • PBJ stands for “Pneumatic Butt on a JANGO“. It was published in the PLOS ONE’s sauropod gigantism collection, hurrah!
  • Archbishop is of course the Natural History Museum’s Tendaguru brachiosaur, which I have been planning to describe since 2004. Still not done. Shameful.
  • Apatosaurus” minimus is a descriptive project. Real work has been done, and I gave a talk about it at SVPCA in 2012. Not much progress since then. Lame.
  • Astrolembospondylus refers to the starship-shaped cervical vertebra of the Barosaurus holotype YPM 429. That project has seen daylight as both an SVPCA talk in 2013 and a PeerJ Preprint — which is great. But once the reviews were in, we should have turned it around and got it submitted as a proper paper. For some reason, we didn’t, and this project, too, is in limbo. Weak.
  • ODP is the Open Dinosaur Project. Do not get me started on that train-wreck.
  • Neck cartilage: giraffe, ostrich, croc. This refers to a comparative dissection project to determine whether sauropods had intervertebral discs. I proposed it as a Masters project twice, but no-one bit; then I offered to up to anyone who wanted it on SV-POW!, with the same (lack of) result. Looks like it’s not sexy enough for anyone to invest the time into, which is a shame because it’s important.
  • Limb cartilage limiting mass refers to the second talk I ever gave, at Progressive Palaeontology in 2004. It’s ridiculous that I never wrote this up. Ridiculous.
  • Haemodynamics refers to Matt’s and my looong-running plans to write up our thoughts about Roger Seymour’s work that suggests blood-circulation issues prevented sauropods from having habitually erect necks. I’m going to blame Matt for this one’s lack of progress. (Not because he’s any more to blame than I am — just because I’ve been taking all the blame so far, and I want to share it around a bit.)
  • Immature sauropods, pop. dynamics. Parts of this made it out in the recent Hone, Farke, and Wedel (2016) paper on dinosaur ontogenetic stages. Not as much as I’d have liked to see, but enough to make a dedicated paper about this not really feasible.
  • Ostrich skull atlas. I made lovely multi-view photos of nearly every bone in my ostrich skull. My plan was, and sort of still is, to publish them all in a text-light paper. No progress on this. I still have a few bones left to photograph, and may need to completely disarticulate the mandible before I can do that.
  • Wealden sauropod vert. analysis. I’d planned, going back to the earliest posts on this blog, to properly redescribe and analyse the many fascinating isolated sauropod vertebrae of the Wealden Formation. This is another one that I gave a ProgPal talk about before getting distracted. Not sure if this will ever happen: I’m still very interested in it, but even more interested in other things.
  • Fossils explained is a series of articles for geologists, explaining various fossil groups in laymen’s terms (here is an example). Darren’s done half a dozen of them. Once many years ago I expressed an interest in doing one on sauropods, and the editor liked the idea. Then … nothing. My bad.
  • Ventral compression bracing is a section that, heaven help us, we somehow decided we should remove from Why Giraffes Have Short Necks and make into its own paper. It got stalled on some croc-dissection work that Matt was doing with his student Vanessa and is now in limbo.

That’s fifteen projects that I had on the go, or planned to work on, four years ago. I make it that two of them (WTH and PBJ) have been published and one (Barosaurus) has made it as far as a the preprint stage. Three more are probably dead for various reasons, and that leaves nine where I’ve made woefully inadequate progress — in most cases, none at all.

Meanwhile, needless to say, I’ve added a bunch more projects to my To Do list since I scribbled this one out. (And to be fair to me, I’ve got a few other projects out in this time that weren’t mentioned in the note: neural spine bifurcation as Matt’s co-author, lead author on intervertebral cartilage and sole on its addendum; I slipped in as last author on Haestasaurus; and I wrote the SPARC briefing paper on evaluating researchers.)

What does all this mean?

I don’t know. Some of those no-progress yet projects are still very much alive in my mind — notably the Archbishop, of course. Others might never happen. Some are 90% done and I should just push them out the door.

One moral of this story is that I shouldn’t have burned 250 hours since Christmas playing Skyrim. But maybe a more constructive one is that it’s just really hard to know what projects are going to take wings and fly and which aren’t. My guess — and I’d love to hear some confirmation or denial in the comments — is that most researchers have a similar palette of half-done projects floating around their hindbrains, continually projecting low-level guilt rays. I guess I long ago gave up on the idea that I would ever finish all my projects, because the only way that would happen would be if I never started any more new ones — and that ain’t gonna happen.

Oh, here’s a better moral: ideas to work on are cheap. In fact Matt and I have so darned many that we sometimes just give them away here on SV-POW!. (I am pretty certain that there are lots more similar project-giveaway posts somewhere here, but we didn’t tag them at the time.)

Ideas are cheap; actual work is hard.

A couple of weeks ago, Mike sent me a link to this interview with ecologist James O’Hanlon, who made this poster (borrowed from this post on O’Hanlon’s blog):

O'Hanlon et al isbeposter

We had a short email exchange which quickly converged on, “This would work well for some projects, but not for others.” That’s the same conclusion I came to in my recent review of my own paper titles: I am increasingly enamored of titles that are full sentences, because then if all someone reads is your title, they still know what you found. But not every paper can be summarized so neatly.

Beginning a tight little internet eddy that will be complete at the end of this post, Andy Farke posted my paper title review post on Facebook and it fired some discussion in the comments. Victoria Arbour wrote, “I’m trying to move more towards ‘sentence’ titles, but it’s difficult to come up with something that’s concise, accurate and nuanced sometimes!” I responded, “Totally agreed. There’s no one size fits all solution. I have no idea how John Foster and I could have turned the Snowmass Haplocanthosaurus title into a sentence that wouldn’t have been a disaster. ‘Concise, accurate, and nuanced’ are all good goals, but they pull in different directions.”

But it got me thinking about the different ways that we can craft our results for effective delivery. The default package is long-form: the paper. Not just long, but narrowly targeted: just about every sub-sub-subfield has a core of diehards who will read your paper because it’s right in their wheelhouse and they basically have to, to stay caught up. You were going to reach them anyway. The real question – the question that, iterated over all of your papers, will decide the shape of your career – is who else are you going to reach? The answer is going to depend a lot on serendipity, but you can improve your chances by building something easily digestible – scattering the seeds of your results over as many brains as possible, to increase the number of successful germinations (which in this metaphor could be anything from citations to one-off collaborations to life-long friendships). Here’s what I have so far.

Four ways to efficiently package your results

I almost wrote, “four ways to weaponize and aerosolize your science”. You’re trying to infect people with your ideas. Here are some potential delivery mechanisms.

First, and already mentioned: a good title. Not “Aspects of the history, anatomy, taxonomy and palaeobiology of good heavens I have lost feeling in my extremities” but, whenever possible, something that either tells people what you found (the sentence title) or at least indicates that you found something interesting (the question title, some ‘hook’ titles – “Why giraffes have short necks”). See these three posts for more.

Wedel and Taylor 2013 bifurcation Figure 9 - bifurcatogram

Congratulations, now you’ve read Wedel and Taylor 2013a (to a first approximation). What are you going to do with all the time we just saved you?

Second, a summary figure. Discussed here. Nice because once people have seen that figure, they basically have your results in one convenient, portable, easily-digestible package. Downside: figures are usually entombed in papers, so this doesn’t count as an outreach maneuver unless you let the figure out into the wild some other way. Blog it, put it on Facebook, do something with it so that it functions as a funnel, catching people and pointing them toward your work.

Third, a punchy poster, like O’Hanlon’s. This has a similar caveat as the summary figure: if the only place people can see it is in its native environment (the paper, the scientific meeting), it’s still only preaching to the converted. Get it out where other people can see it. Second caveat: if the poster doesn’t point to something outside of itself, it doesn’t really count as outreach material. The best part of O’Hanlon’s poster is the QR code. If anyone is unhappy with how brief the poster is, they can follow the link and go down the rabbit hole. The depth of the engagement is in the user’s hands. Corollary: if your poster doesn’t have a QR code or a (tiny)URL, it’s a dead end. Why not make it into a gateway? It’s not a question of either/or, it’s an opportunity for yes/and.

ankylosaur heads by Victoria Arbour

Fourth, an infographic, like this one Victoria Arbour made to summarize some of the results from her big 2013 paper on Alberta ankylosaurs (borrowed from here). I thought it was ingenious when I first saw it (on Facebook), and I still do. You know why? Because I know jack about ankylosaurs, but this thing makes them seem both cool and tractable. Victoria is conveying, “There is structure here, and it makes sense. Let me guide you through it.” I instantly wanted something like this for every group of dinosaurs. You know who will appreciate you building something like this? Every other person besides the half-dozen grognards who work on the exact same thing you do (and maybe them, too). Gratitude leads to citations – people will go out of their way to cite your work just because they want other people to know about it.

Conclusions: give people a destination, give them choices, give them something

Three final points about all of this. First, none of these things work if there’s nowhere for interested parties to go, or nothing for them to find when they get there. If there’s a paper already, it had better justify the interest that made people look at it. Don’t let your catchy title be like the trailer for that movie that was 2 minutes of awesome and 1:58 of zzzzzzz. If there’s no paper yet, what are you pointing people to – a blog, a research website, a PeerJ preprint, some files on FigShare, a YouTube video, your open notebook, what? Give them somewhere to go. Immediate implication: if there’s nowhere else for interested people to go, why are you presenting now? Again: don’t build dead-ends, build gateways.

Next, if you think that crafting a second, tighter package strictly for the purposes of promotion is a bit gauche, here’s another perspective: you’re giving people more choices about how to engage with your work. A paper alone presents a very limited set of options. Read me (or skim me, or look at my figures), or don’t. Some people don’t have the activation energy that requires, and by ‘some people’ I mean everyone outside of your little niche. Most of them will never know that your work even exists. Craft something that will reach those people and give them an easy way in. Even for those closer to home, it may still make their lives easier. Have I actually read Arbour and Currie (2013)? No, but I looked at the pretty figures, because I saw the infographic on Facebook. So when I do need to know something about ankylosaurs (hey, stranger things have happened), I know where to turn – and who to cite. I, the user, have options. Give your users more options, and you may find that you get more users.

Third, it pays to stop and think about how people who aren’t in your narrow sub-sub-subfield are going to find out about your work. Do you have a blog? A Facebook account? Active on a mailing list or a forum? As long as that figure or poster or infographic sits in its native habitat, it’s only reaching the converted. Put it on your blog or on Facebook, now it’s something else, carrying your ideas out into the world: a missive, a missile, a missionary – all from the Latin mittere, ‘to send’. You’re already doing the work. Package it, neatly and tightly, and send it.

– – – – – – –

Many thanks to Victoria Arbour for permission to post her diagram, and for her patience over the 23 months that it has taken me to get around to doing so. You really should go check out Arbour and Currie (2013) – the figures are stunning – and Victoria’s extensive and entertaining series of blog posts that followed. That rabbit hole starts here.

References

 

There’s a new mamenchisaurid in town! It’s called Qijianglong (“dragon of Qijiang”), and it’s the work of Xing et al. (2015).

Life restoration of Qijianglong, apparently by lead author Xing Lidar.

Life restoration of Qijianglong, by Cheung Chungtat.

As far as I can make out, the life restoration is also due to Xing Lida: at least, every instance of the picture I’ve seen says “Credit: Xing Lida”. If that’s right, it’s an amazing display of dual expertise to produce both the science and the art! We could quibble with details, but it’s a hundred times better than I could ever do. [Update: no, it’s by Cheung Chungtat, but being uniformly mis-attributed in the media. Thanks to Kevin for the correction in the comment below.]

There’s a mounted skeleton of this new beast in the museum local to where it was found, though I don’t know how much of the material is real, or cast from the real material. Here it is:

A reconstructed skeleton of Qijianglong now on display in Qijiang Museum

A reconstructed skeleton of Qijianglong now on display in Qijiang Museum

A new sauropod is always great news, of course, and it’s a source of shame to us that we cover so few of them here on SV-POW!. (Just think of some of the ones we’ve missed recently … Leikupal, for example.)

But as is so often the case, the most interesting thing about this new member of the club is its vertebrae — specifically the cervicals. Here they are:

FIGURE 11. Anterior cervical series of Qijianglong guokr (QJGPM 1001) in left lateral views unless otherwise noted. A, axis; B, cervical vertebra 3; C, cervical vertebra 4; D, cervical vertebrae 5 and 6; E, cervical vertebra 7 and anterior half of cervical vertebra 8 (horizontally inverted; showing right side); F, posterior half of cervical vertebra 8 and cervical vertebra 9; G, cervical vertebra 10; H, cervical vertebra 11; I, close-up of the prezygapophy- sis-postzygapophysis contact between cervical vertebrae 3 and 4 in dorsolateral view, showing finger-like process lateral to postzygapophysis; J, close- up of the postzygapophysis of cervical vertebra 5 in dorsal view, showing finger-like process lateral to postzygapophysis. Arrow with number indicates a character diagnostic to this taxon (number refers to the list of characters in the Diagnosis). All scale bars equal 5 cm. Abbreviations: acdl, anterior centrodiapophyseal lamina; cdf, centrodiapophyseal fossa; plc, pleurocoel; pocdl, postcentrodiapophyseal lamina; poz, postzygapophysis; pozcdf, post- zygapophyseal centrodiapophyseal fossa; pozdl, postzygodiapophyseal lamina; ppoz, finger-like process lateral to postzygapophysis; ppozc, groove for contact with finger-like process; przdl, prezygodiapophyseal lamina; sdf, spinodiapophyseal fossa.

Xing et al. (2015), FIGURE 11. Anterior cervical series of Qijianglong guokr (QJGPM 1001) in left lateral views unless otherwise noted. A, axis; B, cervical vertebra 3; C, cervical vertebra 4; D, cervical vertebrae 5 and 6; E, cervical vertebra 7 and anterior half of cervical vertebra 8 (horizontally inverted; showing right side); F, posterior half of cervical vertebra 8 and cervical vertebra 9; G, cervical vertebra 10; H, cervical vertebra 11; I, close-up of the prezygapophy- sis-postzygapophysis contact between cervical vertebrae 3 and 4 in dorsolateral view, showing finger-like process lateral to postzygapophysis; J, close- up of the postzygapophysis of cervical vertebra 5 in dorsal view, showing finger-like process lateral to postzygapophysis. Arrow with number indicates a character diagnostic to this taxon (number refers to the list of characters in the Diagnosis). All scale bars equal 5 cm. Abbreviations: acdl, anterior centrodiapophyseal lamina; cdf, centrodiapophyseal fossa; plc, pleurocoel; pocdl, postcentrodiapophyseal lamina; poz, postzygapophysis; pozcdf, post- zygapophyseal centrodiapophyseal fossa; pozdl, postzygodiapophyseal lamina; ppoz, finger-like process lateral to postzygapophysis; ppozc, groove for contact with finger-like process; przdl, prezygodiapophyseal lamina; sdf, spinodiapophyseal fossa.

(At first, I couldn’t figure out what this pocdl abbreviation meant. Then I realised it was a vanilla posterior centrodiapophyseal lamina. Come on, folks. That element has had a standard abbreviation since 1999. Let’s use our standards!)

The hot news in these cervicals is the presence of what the authors call “a distinct finger-like process extending from the postzygapophyseal process beside a zygapophyseal contact”. They don’t give a name to these things, but I’m going to call them parapostzygapophyses since they’re next to the postzygapophyses. [Update: see the comment from Matt below.]

You can get some sense of this morphology from the figure above — although it doesn’t help that we’re looking at tiny greyscale images which really don’t convey 3d structure at all. The best illustration is part J of the figure:

XingEtA2015-qijianglong-fig11J

What are these things? The paper itself says disappointingly little about them. I quote from page 9:

From the axis to at least the 14th cervical vertebra, a finger- like process extends posteriorly above the postzygapophysis and overlaps onto the dorsolateral surface of the prezygapophysis of the next vertebra (Fig. 11I, J). These processes are unique to Qijianglong, unlike all previously known mamenchisaurids that are preserved with cervical vertebrae (e.g., Chuanjiesaurus, Mamenchisaurus spp., Omeisaurus spp., Tonganosaurus). Therefore, the neck of Qijianglong presumably had a range of motion restricted in sideways.

That’s it.

So what are these things? The authors — who after all have seen the actual fossils, not just the rather inadequate pictures — seem to assume that they are a stiffening adaptation, but don’t discuss their reasoning. My guess — and it’s only a guess — it that they assumed that this is what was going on with these processes because it’s what people have assumed about extra processes on xenarthrous vertebrae. But as best as I can determine, that’s not been demonstrated either, only assumed. Funny how these things seem to get a pass.

Armadillo lumbar vertebrae in posterior, anterior and right lateral views.

Armadillo lumbar vertebrae in posterior, anterior and right lateral views.

So what are these processes? It’s hard to say for sure without having seen the fossils, or at least some better multi-view photos, but the obvious guess is that they are our old friends epipophyses, in extreme form. That is, they are probably enlarged attachment points for posteriorly directed dorsal muscles, just as the cervical ribs are attachment points for posteriorly directly ventral muscles.

It’s a shame that Xing et al. didn’t discuss this (and not only because it would probably have meant citing our paper!) Their new beast seems to have some genuinely new and interesting morphology which is worthy of a bit more attention than they gave it, and whose mechanical implications could have been discussed in more detail. Until more is written about these fossils (or better photographs published) I think I am going to have to suspend judgement on the as-yet unjustified assumption that the parapostzygs were there to make the neck rigid against transverse bending.

A final thought: doesn’t JVP seem terribly old-fashioned now? It’s not just the paywall — apologies to those many of you who won’t be able to read the paper. The greyscaling of the figures is part of it — something that makes no sense at all in 2015. The small size and number of the illustrations is also a consequence of the limited page-count of a printed journal — it compares poorly with, for example, the glorious high-resolution colour multiview illustrations in Farke et al.’s (2013) hadrosaur description in PeerJ. Seems to me that, these days, all the action is over at the OA journals with infinite space — at least when it comes to descriptive papers.

References

  • Farke, Andrew A., Derek J. Chok, Annisa Herrero, Brandon Scolieri and Sarah Werning. (2013) Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids. PeerJ 1:e182. doi:10.7717/peerj.182
  • Xing Lida, Tetsuto Miyashita, Jianping Zhang, Daqing Li, Yong Ye, Toru Sekiya, Fengping Wang & Philip J. Currie. 2015. A new sauropod dinosaur from the Late Jurassic of China and the diversity, distribution, and relationships of mamenchisaurids. Journal of Vertebrate Paleontology. doi:10.1080/02724634.2014.889701

 

How bigsmall was Aquilops?

December 12, 2014

Handling Aquilops by Brian Engh

Life restoration of Aquilops by Brian Engh (CC-BY).

If you’ve been reading around about Aquilops, you’ve probably seen it compared in size to a raven, a rabbit, or a cat. Where’d those comparisons come from? You’re about to find out.

Back in April I ran some numbers to get a rough idea of the size of Aquilops, both for my own interest and so we’d have some comparisons handy when the paper came out.

Archaeoceratops skeletal reconstruction by Scott Hartman. Copyright Scott Hartman, 2011, used here by permission.

Archaeoceratops skeletal reconstruction by Scott Hartman. Copyright Scott Hartman, 2011, used here by permission.

I started with the much more completely known Archaeoceratops. The measurements of Scott Hartman’s skeletal recon (shown above and on Scott’s website – thanks, Scott!) match the measurements of the Archaeo holotype given by Dodson and You (2003) almost perfectly. The total length of Archaeoceratops, including tail, is almost exactly one meter. Using graphic double integration, I got a volume of 8.88L total for a 1m Archaeoceratops. That would come down to 8.0L if the lungs occupied 10% of body volume, which is pretty standard for non-birds. So that’s about 17-18 lbs.

Archaeoceratops and Aquilops skulls to scale

Aquilops model by Garrett Stowe, photograph by Tom Luczycki, copyright and courtesy of the Sam Noble Oklahoma Museum of Natural History.

Archaeoceratops has a rostrum-jugal length of 145mm, compared to 84mm in Aquilops. Making the conservative assumption that Aquilops = Archaeoceratops*0.58, I got a body length of 60cm (about two feet), and volumes of 1.73 and 1.56 liters with and without lungs, or about 3.5 lbs in life. The internet informed me that the common raven, Corvus corax, has an adult length of 56-78 cm and a body mass of 0.7-2 kg. So, based on this admittedly tall and teetering tower of assumptions, handwaving, and wild guesses, Aquilops (the holotype individual, anyway) was about the size of a raven, in both length and mass. But ravens, although certainly well-known, are maybe a bit remote from the experience of a lot of people, so we wanted a comparison animal that more people would be familiar with. The estimated length and mass of the holotype individual of Aquilops also nicely overlap the species averages (60 cm, 1.4-2.7 kg) for the black-tailed jackrabbit, Lepus californicus, and they’re pretty close to lots of other rabbits as well, hence the comparison to bunnies.

Of course, ontogeny complicates things. Aquilops has some juvenile characters, like the big round orbit, but it doesn’t look like a hatchling. Our best guess is that it is neither a baby nor fully grown, but probably an older juvenile or young subadult. A full-grown Aquilops might have been somewhat larger, but almost certainly no larger than Archaeoceratops, and probably a meter or less in total length. So, about the size of a big housecat. That’s still pretty darned small for a non-avian dinosaur.

Although Aquilops represents everything I normally stand against – ornithischians, microvertebrates, heads – I confess that I have a sneaking affection for our wee beastie. Somebody’s just gotta make a little plush Aquilops, right? When and if that happens, you know where to find me.

References

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?

In a comment on the last post, Anonymous wrote:

I was wondering, in the course of your career, have you ever gotten tired of studying sauropods? Not to say that sauropods aren’t interesting, or that you might be losing interest in them, but have you ever looked out the window one day and gone “you know, I’m sick of working on sauropods for a while, I’d like to do some research on (say) stegosaur necks”. I ask this question because many prospective paleontologist nowadays, particularly graduate and undergraduate students, are feeling increasingly pressured towards being pigeonholed in a certain, rather small area of paleontology, e.g., tooth wear in extinct ungulates, histology in dinosaurs or therapsids, or ankle adaptations in Triassic archosaurs. In particular, many students end up working on whatever the professor they are working under gives to them as a project, and come out feeling they are so specialized in this area that they can’t work on anything else even if they wanted to. Though, in your case because sauropods exhibit such weird and diverse neck anatomy, it may not be a problem. In my case, I have been doing work on a group that is very morphologically stereotyped, and while I enjoy doing work on it, it would be nice to branch out into more diverse groups given my interesting in things like functional morphology and paleoecology. I know several other people in my research group feel the same.

I am going to answer first for myself, and then invite Mike and Darren and everyone else to share their thoughts.

For me, two things. First, I don’t always work on sauropods–I have a human anatomy paper in press, and two different projects on mammal skull osteology struggling toward publication, and a couple of bird things. You could be forgiven for thinking that sauropods are all that I do, though, since almost all of my publications to date have been on sauropods. :-) But I have been doing research on non-sauropod things that interest me for many years, they’re just taking longer to see the light of day.

Second, within the admittedly narrow field of sauropods I do many different kinds of projects. To take four consecutive papers: my part of the Brontomerus paper (Taylor et al. 2011a) was mostly writing about North American sauropod diversity in the mid-Mesozoic, whereas for the next paper (Taylor et al. 2011b) I was hacking through the sexual selection literature, and for Yates et al. (2012) I was thinking about the early evolution of pneumaticity, and for Wedel (2012) I was grappling with the internal processes of neurons. So that’s a spectrum of stuff from cell biology to biogeography–sauropodomorphs are just the thread that held all of these disparate bits together. Army ants typically have a central camp or bivouac from which they send out foraging parties in radiating directions. That’s my scientific development in a nutshell.

And I’m still pretty narrow compared to a lot of other folks. Dan Ksepka is best known for his fossil penguin work, but he also described the sauropod Erketu and has published on choristoderes, among other things. By the time he finished his dissertation, Jerry Harris had done a morphological description of a sauropod (Suuwassea) and another of a theropod (Acrocanthosaurus) and had published on pterosaurs and IIRC some other things as well. And then there’s Darren, whose remit is Tetrapoda, and not just for blogging.

One thing you wrote particularly caught my interest:

In particular, many students end up working on whatever the professor they are working under gives to them as a project, and come out feeling they are so specialized in this area that they can’t work on anything else even if they wanted to.

Really? I am having a hard time wrapping me head around that. Does “this area” not butt up against any number of others? I mean, my first project was Rich Cifelli saying, “Hey, why don’t you go identify these sauropod vertebrae?”, which metastasized into the description of Sauroposeidon. But along the way I got interested in:

  1. the diversity of Early Cretaceous North American sauropods;
  2. pneumaticity;
  3. how birds breathe (and, yes, that’s a separate topic from pneumaticity);
  4. neck muscles in birds;
  5. biomechanics and posture of sauropod necks; and
  6. all the weird stuff lurking in the OMNH collection (see for example Bonnan and Wedel 2004 and Taylor et al. 2011a).

That looked like several lifetimes’ worth of work even back in 2000, and it looks like many more now.

Now, I worry that I am sounding like a jerk, because I know–I KNOW–I was handed the most cherry planned-to-be-one-semester undergraduate research project ever. I get that, and I’m as grateful and humble about it as any naturally arrogant genius could be. But still, it seems to me that just about every project involves applying [method] to [taxon] to measure or infer [parameter], and by the time you look into applying the method to other taxa or problems, and into related or complementary or opposing methods, and into other animals that closely related to or in some way analogous to your ‘home’ taxon, and into other parameters or the same parameter in other places or times or clades, you’ve got a pretty full slate of possible things to work on–and this is just a list of areas where you have a head start because you’re already up to speed. If you want to go work on something completely different, who’s stopping you? And if you have intellectual wanderlust but don’t know what to work on, I’ve already written something that might help with that.

But maybe I am misunderstanding your complaint. If the problem is that your research project is narrow, well, that’s a common lament, but the upside is that it’s the kind of limit that might make things easier. If the OMNH crew had found any more of Sauroposeidon, it would have taken longer to prepare, and it would have been more obvious that it was new, and it would have been a lot more work. So I probably wouldn’t have been put on the project, or if I had been, it might have taken up my whole MS and kept me from working on pneumaticity. I am wondering now if a useful heuristic for student projects–or any projects, really–might be, “Keep narrowing it until it looks tractable.”

If you’re bored, start a side project. At best you’ll have a second thread of publishable work, at worst you’ll have an excellent distraction from writing up your thesis.

If the complaint is that your research project is making you too narrow, then maybe you just haven’t been at it long enough to have found all of the interesting links to other methods and taxa and parameters. But I am certain they are there. And discovering them is one of the chief joys of doing research in the first place.

So, there are my thoughts on the desirability–or inevitability–of breadth in one’s research interests. What does everyone else think?

References

Here are two photos of what I infer to be C8 of OMNH 53062, the holotype of Sauroposeidon. The top one was taken by Mike during our visit to the OMNH in 2007. If you’re a regular you may recognize it from several older posts: 1, 2, 3. The bottom one was taken by Mike Callaghan, the former museum photographer at the OMNH, sometime in 1999 or 2000. I used it in Wedel et al. (2000) and Wedel and Cifelli (2005).

Sauroposeidon OMNH 53062 C8 photos compared

You’ll notice that the two photos are far from identical. In both cases, the photographers were up on ladders, as far above the vertebra as they could get, and there are still significant perspective effects. That’s just a fact of life when you’re taking photos of a vertebra that is 1.4 meters long, from anything lower than a helicopter. In Mike Taylor’s shot, the neural spine looms a little too large; in Mike Callaghan’s shot, the prezygapophysis looks a little too small, probably because it was curving off at the edge of the shot. So neither photograph is “right”; both distort the morphology of the specimen in different ways. Here’s how the two images stack up, with the outlines scaled to the same length:

Sauroposeidon OMNH 53062 C8 outlines compared

When I ran a draft of this post past Mike, he wrote (with permission to post):

I think the current draft misses an important point: the warning. We really can’t trust photos, however carefully taken, and however beautifully composited into TNFs*. You’re welcome to quote me as having said I’d have assumed the two C8s were different vertebrae. For that matter, I bet I could have worked up several taxonomically significant characters to distinguish them. Yikes.

* TNF = Taylor Normal Form, i.e., making multi-view photos like the ones here and here.

So the moral is, photos of big specimens almost always involve some distortion. This is clearly not ideal. But I have a plan for fixing it. I am hoping to get back to the OMNH this spring, and the next time I’m there, I’m going to take photos of this vertebra from a zillion angles and make a 3D model through photogrammetry. Happily, Heinrich Mallison has been producing a very helpful series of tutorials on that very topic over at dinosaurpaleo: 1, 2, 3, 4, with more on the way (I’ll update the links here later). Update: Don’t forget to check out Peter Falkingham’s (2012) paper in PE on making photogrammetric models with free software.

Armed with that model, it should be possible to produce a perspective-free lateral view image of the vertebra, to which all of the previous photos can be compared. I can’t use CT data because this vertebra has never been CTed; it’s too big to fit through a medical CT scanner, and probably too fragile to be packed up and shipped to an industrial CT machine like they used on Sue (not to mention that would require a significant chunk of money, which is probably not worth spending on a problem that can be solved in other ways).

So, photogrammetry to the rescue, or am I just deluding myself? Let me know what you think in the comments.

Finally, I should mention that the idea of superseding photographs with 3D photogrammetric models is not original. I got religion last week while I was having beers with Martin Sander and he was showing me some of the models he’s made. He said that going forward, he was going to forbid his students to illustrate their specimens only with photographs; as far as he was concerned, now that 3D models could be cheaply and easily produced by just about everyone, they should be the new standard. Inspiring stuff–now I must go do likewise.

Some previous posts on Sauroposeidon:

References

Why giraffes have short necks

September 26, 2012

Today sees the publication, on arXiv (more on that choice in a separate post), of Mike and Matt’s new paper on sauropod neck anatomy. In this paper, we try to figure out why it is that sauropods evolved necks six times longer than that of the world-record giraffe — as shown in Figure 3 from the paper (with a small version of Figure 1 included as a cameo to the same scale):

Figure 3. Necks of long-necked sauropods, to the same scale. Diplodocus, modified from elements in Hatcher (1901, plate 3), represents a “typical” long-necked sauropod, familiar from many mounted skeletons in museums. Puertasaurus modified from Wedel (2007a, figure 4-1). Sauroposeidon scaled from Brachiosaurus artwork by Dmitry Bogdanov, via commons.wikimedia.org (CC-BY-SA). Mamenchisaurus modified from Young and Zhao (1972, figure 4). Supersaurus scaled from Diplodocus, as above. Alternating pink and blue bars are one meter in width. Inset shows Figure 1 to the same scale.

This paper started life as a late-night discussion over a couple of beers, while Matt was over in England for SVPCA back in (I think) 2008. It was originally going to be a short note in PaleoBios, just noting some of the oddities of sauropod cervical architecture — such as the way that cervical ribs, ventral to the centra, elongate posteriorly but their dorsal counterparts the epipophyses do not.

As so often, the tale grew in the telling, so that a paper we’d initially imagined as a two-or-three-page note became Chapter 5 of my dissertation under the sober title of “Vertebral morphology and the evolution of long necks in sauropod dinosaurs”, weighing in at 41 1.5-spaced pages. By now the manuscript had metastatised into a comparison between the necks of sauropods and other animals and an analysis of the factors that enabled sauropods to achieve so much more than mammals, birds, other theropods and pterosaurs.

(At this point we had one of our less satisfactory reviewing experiences. We sent the manuscript to a respected journal, where it wasn’t even sent out to reviewers until more than a month had passed. We then had to repeatedly prod the editor before anything else happened. Eventually, two reviews came back: one of them careful and detailed; but the other, which we’d waited five months for, dismissed our 53-page manuscript in 108 words. So two words per page, or about 2/3 of a word per day of review time. But let’s not dwell on that.)

Figure 6. Basic cervical vertebral architecture in archosaurs, in posterior and lateral views. 1, seventh cervical vertebra of a turkey, Meleagris gallopavo Linnaeus, 1758, traced from photographs by MPT. 2, fifth cervical vertebra of the abelisaurid theropod Majungasaurus crenatissimus Depéret, 1896,UA 8678, traced from O’Connor (2007, figures 8 and 20). In these taxa, the epipophyses and cervical ribs are aligned with the expected vectors of muscular forces. The epipophyses are both larger and taller than the neural spine, as expected based on their mechanical importance. The posterior surface of the neurapophysis is covered by a large rugosity, which is interpreted as an interspinous ligament scar like that of birds (O’Connor, 2007). Because this scar covers the entire posterior surface of the neurapophysis, it leaves little room for muscle attachments to the spine. 3, fifth cervical vertebra of Alligator mississippiensis Daudin, 1801, MCZ 81457, traced from 3D scans by Leon Claessens, courtesy of MCZ. Epipophyses are absent. 4, eighth cervical vertebra of Giraffatitan brancai (Janensch, 1914) paralectotype HMN SII, traced from Janensch (1950, figures 43 and 46). Abbreviations: cr, cervical rib; e, epipophysis; ns, neural spine; poz, postzygapophysis.

This work made its next appearance as my talk at SVPCA 2010 in Cambridge, under the title Why giraffes have such short necks. For the talk, I radically restructured the material into a form that had a stronger narrative — a process that involved a lot of back and forth with Matt, dry-running the talk, and workshopping the order in which ideas were presented. The talk seemed to go down well, and we liked the new structure so much more than the old that we reworked the manuscript into a form that more closely resembled the talk.

That’s the version of the manuscript that we perfected in New York when we should have been at all-you-can-eat sushi places. It’s the version that we submitted on the train from New York to New Haven as we went to visit the collections of the Yale Peabody Museum. And it’s the version that was cursorily rejected from mid-to-low ranked palaeo journal because a reviewer said “The manuscript reads as a long “story” instead of a scientific manuscript” — which was of course precisely what we’d intended.

Needless to say, it was deeply disheartening to have had what we were convinced was a good paper rejected twice from journals, at a cost of three years’ delay, on the basis of these reviews. One option would have been to put the manuscript back into the conventional “scientific paper” straitjacket for the second journal’s benefit. But no. We were not going to invest more work to make the paper less good. We decided to keep it in its current, more readable, form and to find a journal that likes it on that basis.

At the moment, the plan is to send it to PeerJ when that opens to submissions. (Both Matt and I are already members.) But that three-years-and-rolling delay really rankles, and we both felt that it wasn’t serving science to keep the paper locked up until it finally makes it into a journal — hence the deposition in arXiv which we plan to talk about more next time.

Table 3. Neck-elongation features by taxon.

In the paper, we review seven characteristics of sauropod anatomy that facilitated the evolution of long necks: absolutely large body size; quadrupedal stance; proportionally small, light head; large number of  cervical vertebrae; elongation of cervical vertebrae; air-sac system; and vertebral pneumaticity. And we show that giraffes have only two of these seven features. (Ostriches do the next best, with five, but they are defeated by their feeble absolute size.)

The paper incorporates some material from SV-POW! posts, including Sauropods were corn-on-the-cob, not shish kebabs. In fact, come to think of it, we should have cited that post as a source. Oh well. We do cite one SV-POW! post: Darren’s Invading the postzyg, which at the time of writing is the only published-in-any-sense source for pneumaticity invading cervical postzygapogyses from the medial surface.

As for the non-extended epipophyses that kicked the whole project off: we did illustrate how they could look, and discussed why they would seem to make mechanical sense:

Figure 10. Real and speculative muscle attachments in sauropod cervical vertebrae. 1, the second through seventeenth cervical vertebrae of Euhelopus zdanskyi Wiman, 1929 cotype specimen PMU R233a-δ(“Exemplar a”). 2, cervical 14 as it actually exists, with prominent but very short epipophyses and long cervical ribs. 3, cervical 14 as it would appear with short cervical ribs. The long ventral neck muscles would have to attach close to the centrum. 4, speculative version of cervical 14 with the epipophyses extended posteriorly as long bony processes. Such processes would allow the bulk of both the dorsal and ventral neck muscles to be located more posteriorly in the neck, but they are not present in any known sauropod or other non-avian dinosaur. Modified from Wiman (1929, plate 3).

But we found and explained some good reasons why this apparently appealing arrangement would not work. You’ll need to read the paper for details.

Sadly, we were not able to include this slide from the talk illustrating the consequences:

Anyway, go and read the paper! It’s freely available, of course, like all arXiv depositions, and in particular uses the permissive Creative Commons Attribution (CC BY) licence. We have assembled related information over on this page, including full-resolution versions of all the figures.

In the fields of maths, physics and computer science, where deposition in arXiv is ubiquitous, standard practice is to go right ahead and cite works in arXiv as soon as they’re available, rather than waiting for them to appear in journals. We will be happy for the same to happen with our paper: if it contains information that’s of value to you, then feel free to cite the arXiv version.

Reference

  • Taylor, Michael P., and Mathew J. Wedel. 2012. Why sauropods had long necks; and why giraffes have short necks. arXiv:1209.5439. 39 pages, 11 figures, 3 tables. [Full-resolution figures]