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Please welcome Aquilops americanus

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Life restoration of Aquilops by Brian Engh. Farke et al. (2014: fig. 6C). CC-BY.

Life restoration of Aquilops by Brian Engh. Farke et al. (2014: fig. 6C). CC-BY.

Today sees the description of Aquilops americanus (“American eagle face”), a new basal neoceratopsian from the Cloverly Formation of Montana, by Andy Farke, Rich Cifelli, Des Maxwell, and myself, with life restorations by Brian Engh. The paper, which has just been published in PLOS ONE, is open access, so you can download it, read it, share it, repost it, remix it, and in general do any of the vast scope of activities allowed under a CC-BY license, as long as we’re credited. Here’s the link – have fun.

Obviously ceratopsians are much more Andy’s bailiwick than mine, and you should go read his intro post here. In fact, you may well be wondering what the heck a guy who normally works on huge sauropod vertebrae is doing on a paper about a tiny ceratopsian skull. The short, short version is that I’m here because I know people.

OMNH 34557, the holotype of Aquilops

OMNH 34557, the holotype of Aquilops

The slightly longer version is that OMNH 34557, the holotype partial skull of Aquilops, was discovered by Scott Madsen back in 1999, on one of the joint Cloverly expeditions that Rich and Des had going on at the time. That the OMNH had gotten a good ceratopsian skull out of Cloverly has been one of the worst-kept secrets in paleo. But for various complicated reasons, it was still unpublished when I got to Claremont in 2008. Meanwhile, Andy Farke was starting to really rock out on ceratopsians at around that time.

For the record, the light bulb did not immediately go off over my head. In fact, it took a little over a year for me to realize, “Hey, I know two people with a ceratopsian that needs describing, and I also know someone who would really like to head that up. I should put these folks together.” So I proposed it to Rich, Des, and Andy in the spring of 2010, and here we are. My role on the paper was basically social glue and go-fer. And I drew the skull reconstruction – more on that in the next post.

One of the world's smallest ceratopsians meets one of the largest: the reconstructed skull of Aquilops with Rich Cifelli and Pentaceratops for scale.

One of the world’s smallest ceratopsians meets one of the largest: the reconstructed skull of Aquilops with Rich Cifelli and Pentaceratops for scale. Copyright Leah Vanderburg, courtesy of the Sam Noble Oklahoma Museum of Natural History.

Anyway, it’s not my meager contribution that you should care about. I am fairly certain that, just as Brontomerus coasted to global fame on the strength of Paco Gasco’s dynamite life restoration, whatever attention Aquilops gets will be due in large part to Brian Engh’s detailed and thoughtful work in bringing it to life – Brian has a nice post about that here. I am very happy to report that the three pieces Brian did for us – the fleshed-out head that appears at the top of this post and as Figure 6C in the paper, the Cloverly environment scene with the marauding Gobiconodon, and the sketch of the woman holding an Aquilops - are also available to world under the CC-BY license. So have fun with those, too.

Finally, I need to thank a couple of people. Steve Henriksen, our Vice President for Research here at Western University of Health Sciences, provided funds to commission the art from Brian. And Gary Wisser in our scientific visualization center used his sweet optical scanner to generate the hi-res 3D model of the skull. That model is also freely available online, as supplementary information with the paper. So if you have access to a 3D printer, you can print your own Aquilops – for research, for teaching, or just for fun.

Cloverly environment with Aquilops and Gobiconodon, by Brian Engh (CC-BY).

Cloverly environment with Aquilops and Gobiconodon, by Brian Engh (CC-BY).

Next time: Aquilöps gets röck döts.

Reference

Farke, A.A., Maxwell, W.D., Cifelli, R.L., and Wedel, M.J. 2014. A ceratopsian dinosaur from the Lower Cretaceous of Western North America, and the biogeography of Neoceratopsia. PLoS ONE 9(12): e112055. doi:10.1371/journal.pone.0112055



Reconstructing the skull of Aquilops

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As I mentioned in my first post on Aquilops, I drew the skull reconstructions that appear in figure 6 of the paper (Farke et al. 2014). I’m writing this post to explain that process.

We’ve blogged here before about the back-and-forth between paleontologists and artists when it comes to reconstructing and restoring extinct animals (example 1, example 2). Until now, I’ve always been the guy making suggestions about the art, and asking for changes. But for the Aquilops project, the shoe was on the other foot: Andy Farke was my ‘client’, and he had to coach me through drawing a basal ceratopsian skull – a subject that I was definitely not familiar with.

Aquilops skull - Farke et al 2014 figure 3

I started from the specimen, OMNH 34557, which is more complete than you might think at first glance. The skull is folded over about 2/3 of the way up the right orbit, so in lateral view it looks like the top of the orbit and the skull roof are missing. They’re actually present, just bent at such a sharp angle that they’re hard to see at the same time as the lateral side of the skull.

Archaeoceratops lateral

I also used a cast skull of Archaeoceratops as a reference – it’s clear from what we have of Aquilops that the two animals were pretty similar.

Aquilops skull lateral 1 - outline

I started with this pencil outline on a piece of tracing paper.

Aquilops skull lateral 2 - rough stipple

And then I went right ahead and stippled the whole thing, without showing it to Andy until I was done. Yes, that was dumb. Noe the lack of sutures in this version.

Aquilops skull lateral 3 - rough stipple marked up

I added sutures and sent it off to Andy, who sent it back with these suggested changes. At this point I realized my error: I had already spent about a day and a half putting ink on the page, and I’d have to either start all over, or do a lot of editing in GIMP. I picked the latter course, since there were plenty of areas that were salvageable.

Aquilops skull lateral 4 - redrawn bits

Next I did something that I’d never done before, which is to redraw parts of the image and then composite them with the original in GIMP. Here’s are the redrawn bits.

Aquilops skull lateral 5 - penultimate version

With those bits composited in, and a few more tweaks to sutures, we got to this version, which was included in the submitted manuscript.

Aquilops skull lateral 6 - beak curvature issue

Then we brought Brian Engh in to do the life restorations. When Brian takes on a project, he does his homework. If you’ve seen his post on painting Aquilops, you know that all of the ferns in the Cloverly scene are based on actual fossils from the Cloverly Formation. Brian came to Claremont this summer and he and Andy and I spent most of a day at the Alf Museum looking at the specimen and talking about possible layouts for the full-body life restorations. He took a bunch of photos of the specimen while he was there, and a day or two later he sent us this diagram. He’d chopped up his photos of the skull to produce his own undistorted version to guide his painting, and in doing so he’d noticed that I had the line of the upper jaw a bit off.

Aquilops skull lateral 7 - partly revised

That required another round of digital revisions to fix. It ended up being a lot more work than the earlier round of edits in GIMP, because so many features of the skull had to be adjusted. I ended up cutting my own skull recon into about 8 pieces and then stitching them back together one by one. Here’s what the image looked like about halfway through that process. The back of the skull, orbit, and beak are all fixed here, but the snout, cheek, and maxilla don’t yet fit together.

Aquilops skull lateral 8 - final published version

After a little more work, I got the whole thing back together, and this is the final version that appears in the paper. It is not perfect – the area in front of the orbit where the frontal, nasal, maxilla, and premaxilla come together is a bit dodgy, and I’m not totally happy with the postorbital. But eventually you have to stop revising and ship something, and this is what I shipped.

Aquilops dorsal recon lineup for SV-POW

I did the dorsal view after the submitted version of the lateral view was finished. It went a lot faster, for several reasons:

  • Most of the gross proportional issues were already sorted out from doing the lateral view first.
  • The bilateral symmetry didn’t cut down on the number of dots but it did cut the conceptual workload in half.
  • I did all my roughs in pencil and didn’t start inking until after we had almost all of the details hashed out.

I did have to revise the dorsal view after getting feedback from Brian about the lateral view, but that revision was pretty minor by comparison. I stretched the postorbital region and tinkered a bit with the face and the frill, and both of those steps required putting in some new dots, but it was still just one afternoon’s worth of work. Here’s the final dorsal recon:

Aquilops dorsal skull reconstruction - final published version

In addition to the Life Lessons already noted in this post, I learned (or rather relearned) this important principle: if you do a big drawing and then shrink it down to column width, fine errors – a shaky line here, an ugly dot there – get pushed down below the threshold of perception. But there’s a cost, too, which is that uneven stippling becomes more apparent. I was skipping back and forth a lot between 25% image scale to see where the problem areas were, and 200% to revise the lines and dots accordingly.

All in all, it was a fun project. It was my most ambitious technical illustration to date, I learned a ton about ceratopsian skulls, and it was nice to get to make at least one substantial contribution to the paper.

Now, here’s the take-away: this is my reconstruction, and both of those words are important. “Reconstruction” because it has a lot of extrapolation, inference, and sheer guesswork included. “My” because you’re getting just one possible take on this. You can download the 3D files for the cranium and play with them yourselves. I hope that other artists and scientists will use those tools to produce their own reconstructions, and I fully expect that those reconstructions will differ from mine. I look forward to seeing them, and learning from them.

For other posts about my stippled technical illustrations, see:

Reference

Farke, A.A., Maxwell, W.D., Cifelli, R.L., and Wedel, M.J. 2014. A ceratopsian dinosaur from the Lower Cretaceous of Western North America, and the biogeography of Neoceratopsia. PLoS ONE 9(12): e112055. doi:10.1371/journal.pone.0112055


How bigsmall was Aquilops?

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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


Aquilops in today’s LA Times

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Aquilops in LA Times - scan

Hey, just a quick announcement this time: today’s LA Times has a nice little article on Aquilops on page A6. It’s also available online here. Good luck tracking down a hardcopy – our local Barnes & Noble doesn’t carry the LA Times (not sure which party that reflects worse on), and I got the last copy from a gas station down the street. I’m so happy that they used Brian’s artwork!

I’ll put up a better scan when I get back to work next week. Later: I did.


My early Christmas present: a dead corn snake

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A friend’s daughter owned a pet corn snake, and a hamster. About a month ago, the former got into the latter’s cage — and in a reversal of the usual course of such events, sustained some nasty injuries. As snakes often do, it struggled to recover, and the wound seems to have necrotised.

This morning I got an email from the friend saying that the snake had died, and asking whether I would like it. I managed to restrain my enthusiasm for long enough to express condolences to the daughter; and an hour later, the snake was delivered!

IMG_1861-cleaned

Here it is — as with all these images, click through for the full resolution. I’ve learned that it’s difficult to measure the length of a snake — they don’t lay out straight in the way that you’d like, even when they’re dead — but as best I can make out, it’s 120 cm long. It weighs 225 g, but don’t tell Fiona I used the kitchen scales.

The hamster wound is very apparent, just behind the neck, on the left hand side. Here’s the head and neck in close-up:

IMG_1847-cleaned

Ouch — very nasty. It can’t have been pleasant watching a pet linger on with a wound like that.

He (or she? How do you sex a snake?) was a handsome beast, too. Here’s the head. You can easily make out the individual large scales covering it, and make out some of the shape of the skull.

IMG_1852-cleaned

The skulls of snakes are beyond weird. Here is one from an unspecified non-venomous snake at Skulls Unlimited (i.e. probably not a corn snake):

variants_large_3861

Hopefully at some point I’ll be able to show you my own snake’s skull. In the mean time, this guy says he has a corn-snake skull, but the photography’s not very good.

Finally, here is my snake, mouth open, showing the pterygoid teeth on the roof of the mouth:

IMG_1857-cleaned

What next? It seems clear that bugging is the only realistic way to free up the skeleton, and this may be the specimen that persuades me to invest in a proper colony of dermestids rather than just relying on whatever inverts happen to wander past.

It might be worth trying to skin and gut the snake first. Gutting will be easy; skinning might be very difficult. I think that removing the skin from the skull without damaging the very delicate bones might be impossible. Can dermestids cope with snake skin?

I’m taking advice!

 


My neck-cartilage angle paper is out!

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Arriving as an early Christmas present, and coming in just a week before the end of what would otherwise have been a barren 2014, my paper Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs is out! You can read it on PeerJ (or download the PDF).

Figure 4. Effect of adding cartilage to the neutral pose of the neck of Diplodocus carnegii CM 84. Images of vertebra from Hatcher (1901:plate III). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 2.

Figure 4: Effect of adding cartilage to the neutral pose of the neck of Diplodocus carnegii CM 84. Images of vertebra from Hatcher (1901:plate III). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 2.

Yes, that posture is ludicrous — but the best data we currently have says that something like this would have been neutral for Diplodocus once cartilage is taken into account. (Remember of course that animals do not hold their necks in neutral posture.)

The great news here is that PeerJ moved quickly. In fact here’s how the time breaks down since I submitted the manuscript (and made it available as a preprint) on 4 November:

28 days from submission to first decision
3 days to revise and resubmit
3 days to accept
15 days to publication

TOTAL 49 days

Which of course is how it ought to be! Great work here from handling editor Chris Noto and all three reviewers: Matt Bonnan, Heinrich Mallison and Eric Snively. They all elected not to be anonymous, and all gave really useful feedback — as you can see for yourself in the published peer-review history. When editors and reviewers do a job this good, they deserve credit, and it’s great that PeerJ’s (optional) open review lets the world see what they contributed. Note that you can cite, or link to, individual reviews. The reviews themselves are now first-class objects, as they should be.

At the time of writing, my paper is top of the PeerJ home-page — presumably just because it’s the most recent published paper, but it’s a nice feeling anyway!

Screenshot from 2014-12-23 10:39:34

 

A little further down the front-page there’s some great stuff about limb function in ratites — a whole slew of papers.

Well, I’m off to relax over Christmas. Have a good one, y’all!


What have you done with Aquilops!?

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Awesome things, that’s what. In a previous post I asked people to make cool things with Aquilops. And you have. In spades. Here’s a compilation of the best things so far.

Aquilops sketch by Mike Keesey

First, a blast from the past. As far as I know, the first life restoration of Aquilops was actually this sketch by Mike Keesey, which he executed while sitting in the audience for Andy Farke’s talk on our not-yet-named ceratopsian at SVP 2013. Mike kindly sat on it for over a year, and then posted it to his Flickr stream after the paper came out last month. A small adventure ensued – a site called News Maine (which I refuse to link to) used Mike’s image without his knowledge or permission in their Aquilops article. When he wrote to them and pointed out their breach, they swapped his image for one of Brian Engh’s, but still did not provide an image credit! Now their Aquilops article appears to have been taken down entirely. Good riddance.

Mike says of his Aquilops, “I’d like to make it clear that it was done from looking at a slide during a talk and not meant to be rigorous or accurate.” But I dig it (and I did get his permission to repost it!). It has character – it looks weary, maybe a little grumpy, like a pint-size curmudgeon. And it definitely wants you kids to get off its damn lawn. If you want to see more of Mike’s sketches in this style from SVP 2013 – and you should, they’re very good – go here.

Extreme Aquilops papercraft skull by Gareth Monger

Dinosaur skull or starfighter? You decide!

Second, people have taken the paper skull I posted before and used it as the raw material for significantly more awesome versions. Gareth Monger made the more-fully-3D version shown here, and posted about it at his Pteroformer blog. I think it’s totally wicked, and I’d make my own if I had the patience and skill.

Aquilops puppet - Alf museum

But I don’t. Fortunately, there is help for me: Kathy Sanders, the Director of Outreach at the Raymond M. Alf Museum here in Claremont (where Aquilops lead author Andy Farke is based), took my skull drawings and turned them into a papercraft finger puppet suitable for all ages. I know it’s suitable for all ages because at the Alf Museum’s Family Science Discovery Day last Saturday, almost every one of many children going through the museum had an Aquilops puppet on one hand. London and I each made one, and we spent a lot of time Saturday evening goofing off with them.

IMG_3273

Alas, poor Aquilops! I knew him, readers; a fellow of minuscule crest, of most excellent beak; he hath borne my career on his head a whole month; and now, how adored in my imagination he is!

You can see a little video of the puppet in action on Ashley Hall’s Tumblr, Lady Naturalist. And you can get the files to make your own from the Alf Museum website, here. You’ll also need a couple of brads to make the jaw hinge joints, and a smaller-than-normal hole punch is handy for making the holes, but ultimately any method that produces a small, round hole will work.

Finished-Aquilops-2 by James Appleby

Heads not enough for you? Want a complete Aquilops to call your own? You are in luck – not one but two such critters have emerged from the virtual undergrowth. James Appleby, a 16-year-old who blogs at Edaphosaurus.com, did something that would not have occurred to me in a million years: he took the baby Aquilops (Aquilopses?) from Brian Engh’s awesomely detailed Cloverly environment scene and made a paper model. It’s a great example of how releasing something under an open license – in this case CC-BY – encourages people to do cool new things with your work. You can get the parts here.

Aquilops paper toy by Gareth Monger

Want something cuter? Try this papercraft Aquilops toy, another creation of the apparently indefatigable Gareth Monger. Post and parts here. I love Gareth’s concluding exhortation: “Edit it, share it, distribute it. Keep it fun and keep it free.” That’s practically the Aquilops motto.

I’m probably just scratching the surface here. I know there has been a flowering of awesome Aquilops restorations on DeviantART. David Orr has an adorkable ‘Pixel Aquilops t-shirt on Redbubble. Tell me what else is out there, and keep making new stuff. Let’s keep this thing rolling.

And a big thank you to Mike, Gareth, Kathy, Ashley, and James for making cool Aquilops stuff and posting it for people to see and build. You all rock.


Sideshow Apatosaurus sans background

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apatosaurus-maquette-whole-lateral cropped - angle 2

I made these for my own use in talks, and then thought, why be selfish? Like everything else on this blog, these images are now released to the world under the CC-BY license. Have fun with them.

apatosaurus-maquette-whole-lateral cropped

You can read my review of the Sideshow Apatosaurus here; the TL;DR is that it’s awesome. And if you’re bummed that you missed out on getting one last time around, they’re rereleasing it later this spring with a slightly different paint job – details here.



The “finger-like” parapostzygapophyseal processes of Qijianglong

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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

 


The planned vandalism of the Natural History Museum: a modest proposal

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Go to Google and do a picture search for “natural history museum”. Here are the results I get. (I’m searching the UK, where that term refers to the British museum of that name — results in the USA may very.)

google-search-for-nhm

In the top 24 images, I see that half of them are of the building itself — rightly so, as it’s a beautiful and impressive piece of architecture that would be well worth visiting even if it was empty. Of the rest, ten are of specimens inside the museum: and every single one of them is of the Diplodocus in the main hall. (The other two photos are from the French natural history museum, so don’t really belong in this set. Not coincidentally, they are both primarily photos of the French cast of the same Diplodocus.)

The NHM’s Diplodocus — I can’t bring myself to call it “Dippy” is the icon of the museum. It’s what kids go to see. It’s what the museum used as the basis of the logo for the 2005 SVPCA meeting that was held there. It’s essentially the museum mascot — the thing that everyone thinks of when they think of the NHM.

And rightly so: it’s not just a beautiful specimen, it’s not just sensational for the kids. As the first cast ever made of the Carnegie specimen CM 84, it’s a historically important object in its own right. It was the first mounted Diplodocus ever, being presented in 1905 before the the original material was even on display in Pittsburgh.

diplodocus_nocopyright

As a matter of fact, this cast was the very first mounted sauropod to be publicly displayed: that honour is usually given to the AMNH Apatosaurus, but as museum-history expert Ilja Nieuwland points out:

The London ‘Dippy’ was in fact the first sauropod on public display, if only for three days in early July of 1904, in the Pittsburgh Exposition Society Hall.

There you have the Natural History Museum Diplodocus: the symbol of the museum, an icon of evolution, a historical monument, a specimen of great scientific value and unparalleled symbolism.

So naturally the museum management want to tear it down. They want to convert the Diplodocus hall into a blue whale hall. Because the museum doesn’t already have a blue whale hall.

Or, no — wait — it does already have a blue whale hall. That’s it. That’s what I meant to say. And very impressive it is, too.

16222408

I don’t mind admitting that the whale hall is my second favourite room in the museum. Whenever I go there as a tourist (rather than as a scientist, when I spend all my time in the basement), I make sure I see it. It’s great.

The thing is, it’s already there. A museum with a whale hall does not need another whale hall.

Obviously anticipating the inevitable outcry, the museum got all its ducks in a row on this. They released some admittedly beautiful concept artwork, and arranged to have opinion pieces written in support of the change — some by people who I would have expected to know better.

One of the more breathtaking parts of this planned substitution is the idea that Diplodocus is no longer relevant. The NHM’s director, Sir Michael Dixon says the change is “about asking real questions of contemporary relevance”. He says “going forward we want to tell more of these stories about the societally relevant research that we do”. This “relevance” rhetoric is everywhere. The museum “must move with the times to stay relevant”, writes Henry Nicholls in the Guardian.

There was a time when Diplodocus was relevant, you know: waaay back in the 1970s. But time has moved on, and now that’s 150,000,035 years old, it’s become outdated.

Conversely, the rationale for the whale seems to be that they want to use it as a warning about extinction. But could there ever be a more powerful icon of extinction than a dinosaur?

The thing is, the right solution is so obvious. Here’s what they want to do:

2528769B00000578-2930638-image-a-19_1422525497076

Clearly the solution is, yes, hang the whale from the ceiling — but don’t remove the Diplodocus. Because, seriously, what could be a better warning about extinction than the juxtaposition of a glorious animal that we lost with one that we could be about to lose?

All this argument about which is better, a Diplodocus or a blue whale: what a waste of energy. Why should we have to choose? Let’s have both.

I’ve even had an artist’s impression made, at great expense, to show how the combination exhibit would look. Check it out.

2528769B00000578-2930638-image-a-19_1422525497076-art

(If anyone would like to attempt an even better rendering, please by my guest. Let me know, and I’ll add artwork to this page.)

So that’s my solution. Keep the museum’s iconic, defining centrepiece — and add some more awesome instead of exchanging it. Everyone wins.


Help us assemble all of the museum abbreviations

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Kaatedocus by Brian Engh

Kaatedocus is heading to the sidebar to help the cause.

We have a new page on the sidebar – here – where we’re collecting as many museum abbreviations as possible, the idea being that you can copy and paste them into your papers to rapidly populate the ‘Museum Abbreviations’ section. I grabbed about 100 from my own previous papers and a handful of others, so currently the list is highly skewed toward museums with (1) sauropods (2) that I’ve had reason to yap about. I’ve probably missed tons of museums that are important for people working on hadrosaurs or stegosaurs or (shudder) mammals. From here on out the list will grow as people suggest additions and edits in the comments on that page. So please get on over there and contribute!

Completely unrelated eyeball-bait art courtesy of Brian Engh, who writes,

I don’t even remember drawing this, I just found it lying around and spruced it up a bit today. It’s supposed to be some kinda diplodocid, maybe Kaatedocus, but I think the main goal of the drawing was to draw one with a sense of weight that felt right given that their center of mass is supposed to be so far back. I like the idea of them getting startled and popping up every now and again… [see also–MJW]


Zallinger’s “Age of Reptiles” mural at the Yale Peabody Museum

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In 2012, Matt and I spent a week in New York, mostly working at the AMNH on Apatosaurusminimus and a few other specimens that caught our eye. But we were able to spend a day at the Yale Peabody Museum up in New Haven, Connecticut, to check out the caudal pneumaticity in the mounted Apatosaurus (= “Brontosaurus“) excelsus, YPM 1980, and the bizarrely broad cervicals of the Barosaurus lentus holotype YPM 429.

While we there, it would have been churlish not to pay some attention to the glorious and justly famous Age of Reptiles mural, painted by Rudolph F. Zallinger from 1944-1947.

So here it is, with the Brontosaurus neck for scale:

IMG_0501-zallinger-mural

Click through for high resolution (3552 × 2664).

And here is a close-up of the most important, charismatic, part of the mural:

IMG_0500-zallinger-mural

Again, click through for high resolution (3552 × 2664).

That’s your lot for now. We’ve long promised a proper photo post of the Brontosaurus mount itself, and I’ll try to get that done soon. For now, it’s just scenery.


My name is Giraffatitan, king of kings

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Look on my works, ye mighty, and despair!

DSCN0476

[Giraffatitan brancai paralectotype MB.R.2181 (formerly HMN S II), mounted skeleton in left anteroventrolateral view. Presacral vertebrae sculpted, skull scaled and 3d-printed from specimen T1. Round the decay of that colossal wreck, boundless and bare, the lone and level sands stretch far away.]


Two important new palaeobiological hypotheses regarding diplodocids

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fat-necked-apatosaurs-make-the-world-go-round

The first hypothesis is that, contra Elk (1972), all Brontosauruses were rather fat at one end, then much fatter in the middle, then thin at the other end.

The second theory is that Diplodocus was dumb. Evidence is here presented in the form of an important new life restoration by Matthew Taylor.

derpolodocus

References

  • Elk, Anne. 1972. Anne Elk’s Theory on Brontosauruses. Reprinted in: Chapman, G., Cleese, J., Gilliam, T., Idle, E., Jones, T. and Palin, M. (eds). Just the Words, Volume 2. Methuen, London, 118-120.

New information on the integumentary ornamentation of Aquilops americanus (that I have on my shoulder)

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Aquilops tattoo

My 40th birthday present from Vicki. I commissioned the art from Brian Engh. I bow to no one in my love for his original Aquilops head reconstruction:

Life restoration of Aquilops by Brian Engh. Farke et al. (2014: fig. 6C). CC-BY.

Life restoration of Aquilops by Brian Engh. Farke et al. (2014: fig. 6C). CC-BY.

BUT it’s waaay too detailed for a tattoo unless I wanted a full back piece. I sent Brian this sketch to convey what I wanted – to emphasize the strong lines of the piece, punch up the spines and spikes, basically shift it toward a comic book style without devolving into caricature:

Aquilops tattoo - Matt sketch raw

Originally I was going to have Aquilops‘ name and year of discovery in the tat. I decided to drop the lettering, for several reasons. One, it won’t hold up as well over the next few decades. Two, if someone is close enough to read it, we’ll probably be talking about the tattoo already. Third, the tattoo is a better conversation starter without a caption. First I get to tell people what Aquilops is, then I get to explain what ‘fourth author‘ means. ;-)

As he did for the original Aquilops head recon, Brian sent a selection of possible color schemes, mostly based on those of extant lizards. I couldn’t decide which I liked best, so I talked it over with my tattoo artist, Tanin McCoe at Birch Avenue Tattoo in Flagstaff, Arizona. I wasn’t just interested in what looks good on paper, but what would work well with my skin tone and still look good 20 years from now. Tanin really liked the earth-tone color scheme with the dark stripe across the eye, so that’s how we went. The tattoo Aquilops is facing left instead of right because it’s on my left shoulder – my right deltoid was already occupied.

They do good work at Birch Avenue – Vicki’s gotten three pieces there, including this skeleton key that was also done by Tanin:

Vicki skeleton key tattoo - 1200

Yes, the key’s bit is a human sphenoid – that was my idea.

Anyway, I’m super-happy with the tattoo, and I’m glad it’s healed enough to show off. Thanks, Brian and Tanin!



My adventure in the world of Humanities

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I got back this lunchtime from something a bit different in my academic career. I attended Court and Spark: an International Symposium on Joni Mitchell, hosted by the university of Lincoln and organised by Ruth Charnock.

court-and-spark-symposium-poster_v0-2

I went mostly because I love Joni Mitchell’s music. But also partly because, as a scientist, I have a necessarily skewed perspective on scholarship as a whole, and I want to see whether I could go some way to correcting that by immersing myself in the world of the humanities for a day.

My own talk was on “Musical progress and emotional stasis from Blue (1971) to Hejira (1976)”. I’ve posted the abstract and the slides on my publications list, and you can get a broad sense of what was in from this blog-post about Hejira which talks a lot about Blue. (The talk was inspired by that blog-post, but it had a lot of new material as well.) I plan to write it up as a paper when I get a moment.

I was up in session 3, after lunch, so I’d had a couple of session to get used to how things were done. As far as I can tell, it seemed to go over pretty well, and there was some good discussion afterwards.

So how does a humanities conference stack up against a science one?

They were much less different than I’d imagined they would be. The main difference is that talks are called “papers”. As in “Did you hear the paper about X?”, or “I gave a paper on Y”. There was perhaps a little more time dedicated to discussion than at SVP or SVPCA.

Because I didn’t know how to dress, I erred on the side of conservative. As a result, I was the only man in the building wearing a tie, and was consequently the most overdressed person present — something that has never happened to me before, and likely never will again. (I typically wear a tie two or three times a year.)

All in all I had a great time. I’m currently in the process of trying to get my eldest son to appreciate Joni (he’s more of a prog-metal fan, which I can respect); against that backdrop, it was great to be surrounded be people who get it, who know all the repertoire, and who recognise allusions dropped into conversation. Also: beers with fellow-travellers between the main conference and the Maka Maron interview event in the evening; wine reception afterwards; Chinese food after that; after-party when we couldn’t eat any more food. (It was nice being invited along to that, given that I’d never any of the people before yesterday, and only even exchanged email with one of them.)

I’d had to get up 4:45 in the morning to drive up to Lincoln in time for the conference, so all in all it was a long day. But well worth doing.

I’d do it again in a heartbeat.

 


More thoughts on the Joni Mitchell conference

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I wanted to get my initial report on the Joni Mitchell conference out quickly. But since posting it, more thoughts have bubbled up through my mind. I’m thinking here mostly about how a humanities conference varies from a science one. Now of course this is only anecdote, nothing like a scientific survey: my sample size is one conference (for humanities) and only one field for science (vert palaeo, natch), so we should beware of generalising from these observations.

With that understood …

The Minerva Building of the University of Lincoln, where the main conference sessions took place.

The Minerva Building of the University of Lincoln, where the main conference sessions took place.

The Joni conference had mostly parallel sessions: a pair of panels early in the morning, then a pair in the later morning, then three simultaneous panels in the after-lunch session before dropping down to a single plenary session for the later afternoon. (My talk was in one of the three parallel panels, so less well attended than it might otherwise have been.) I don’t know how common this is in humanities conferences, but it’s never done at SVPCA or ProgPal. SVP, of course, does run parallel sessions — but then that is a very big meeting, with thousands of delegates.

I used the word “panel” in that description, which I’ve not come across in science conferences. It refers to one of a set of parallel sessions. The idea is that all the talks in a panel are on a somewhat related subject, and the panel ends with all the speakers coming back to the front together, for a discussion with the audience and among themselves. This is actually a really nice way to run things — much better than the very nominal Q&As at the end of SVPCA talks. It helps you to develop a sense of who people are, as well as digging deeper into the topics. My sense is that this is pretty typical of humanities conferences.

One less positive difference is that it seems far more acceptable in the humanities to read papers out loud from manuscripts. By no means everyone did this, but quite a few did, and it seemed to be thought normal. This did work out well for me in one respect, though. Because of the parallel panels, I missed a talk I would have liked to have heard, on using Joni’s music in therapeutic contexts. But when I later spoke to the author of that paper, she was able to give me a hardcopy of the talk. (I read it today.)

Did I say “Joni”? One aspect of this conference that corresponded pretty well with my prejudices was a sort of liberal guilt that popped up its head from time to time. Most of the speakers referred to our subject as “Joni” rather than “Mitchell”. In the round-table discussion at the end, someone suggesting this implied an unwarranted level of intimacy, and indicated an unconscious sexism on the part of the participants. There was quite a bit of agreement with this, but I don’t buy it. I think we refer to Joni Mitchell as “Joni”, when we don’t refer to Paul Simon as “Paul” for two reasons: one practical, one fundamental. First, because Joni is a rare and distinctive name, whereas Paul could be Paul McCartney; and second because the high level of self-disclosure in Joni’s music creates the impression of intimacy. I don’t think it’s anything to do with her being female and Simon being male.

Similarly, there was some angst about cultural appropriation regarding Joni’s use of jazz idioms, and particularly about her appearance as a black man on the cover of Don Juan’s Reckless Daughter (1977):

9000000014145

I can certainly see how that cover makes people uncomfortable in 2015, and I can easily imagine that it would have done even in the very different climate of 1977. On the other hand, it felt a bit strange to be part of a 100% white audience debating this. I’m not sure what conclusion would be appropriate, so I won’t attempt one.

Finally, the demographics of the conference were maybe the biggest surprise. I’m not good at noticing race, so I may have missed someone; but as far as I’m aware there was not a single non-caucasian face at the conference. And perhaps even more surprising, in a conference about a feminist icon[*], although the attendance was about 50-50 men and women, the programme was dominated by male speakers. From a quick scan of the programme, I make it 15 men to 7 women, so more than twice as many.

As with most of what I’ve said here, I have no idea what to make of this. I just offer it up as an observation, and I’ll be glad to know what others make of it all.


[*] Joni Mitchell has explicitly disowned the description “feminist” on more than one occasion; but as a woman who not only held her own in man’s world but by most judgements dominated it, she is certainly an admirable example of practical, if not dogmatic, feminism.

 


Diplodocid sacra of the AMNH (and indeed the Carnegie Museum)

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Back in 2012, when Matt and I were at the American Museum of Natural History to work on Apatosaurus” minimus, we also photographed some other sacra for comparative purposes. One of them you’ve already seen — that of the Camarasaurus supremus holotype AMNH 5761. Here is another:

diplodocus-sacrum-composite

(Click through for glorious 3983 x 4488 resolution.)

This is AMNH 3532, a diplodocid sacrum with the left ilium coalesced and the right ilium helpfully missing, so we can see the structure of the sacral ribs. Top row: dorsal view, with anterior to the left; middle row, left to right: anterior, left lateral and posterior views; bottom row: right lateral view.

As a matter of fact, we’ve seen this sacrum before, too, in a photo from Matt’s much earlier AMNH visit. But only from a left dorsolateral perspective.

When we first saw this, it didn’t even occur to us that it could be anything other than good old Diplodocus. And indeed it’s a pretty good match for the same area in the CM 84/94 cast in the Museum für Naturkunde Berlin (this image extracted from Heinrich Mallison’s beautiful giant composite):

img_4853-img_4886-v3-sm-sacrum

And the general narrowness of the AMNH sacrum says Diplodocus to me. But what is that expectation of narrowness based on? When I compared the AMNH specimen with Hatcher’s (1901) ventral-view illustration in his classic Diplodocus monograph, I had second thoughts:

Hatcher (1901: fig. 9). Inferior view of sacrum and ilia of Diplodocus carnegii (No. 94), one tenth natural size; bp, public peduncle; is, ischiadic peduncle; a, anterior end; p, posterior end.

Hatcher (1901: fig. 9). Inferior view of sacrum and ilia of Diplodocus carnegii (No. 94), one tenth natural size; pp, public peduncle; is, ischiadic peduncle; a, anterior end; p, posterior end.

That is a much wider sacrum than I’d expected from Diplodocus.

So what is going on here? Is Diplodocus a fatter-assed beast than I’d realised? I am guessing not, since my expectation of narrowness has been built up across years of looking at (if not necessarily paying much attention to) Diplodocus sacra.

So could it be that CM 94, the referred specimen that Hatcher used to make up some of the missing parts of the CM 84 mount, is not Diplodocus?

Well. That is certainly now how I expected to finish this post. Funny how blogging leads you down unexpected paths. It’s a big part of why I recommend blogging to pretty much everyone. It forces you to think down pathways that you wouldn’t otherwise wander.

References

  • Hatcher, Jonathan B. 1901. Diplodocus (Marsh): its osteology, taxonomy and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63 and plates I-XIII.

 


So what were apatosaurs doing with their crazy necks?

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We’ve noted that the Taylor et al. SVPCA abstract and talk slides are up now up as part of the SVPCA 2015 PeerJ Collection, so anyone who’s interested has probably taken a look already to see what it was about. (As an aside, I am delighted to see that two more abstracts have been added to the collection since I wrote about it.)

It was my privilege to present a talk on our hypothesis that the distinctive and bizarre toblerone-shaped necks of apatosaurs were an adaptation for intraspecific combat. This talk was based on an in-progress manuscript that Matt is lead-authoring. Also on board is the third SV-POW!sketeer, the silent partner, Darren Naish; and artist/ethologist Brian Engh.

Here is our case, briefly summarised from five key slides. First, let’s take a look at what is distinctive in the morphology of apatosaur cervicals:

Screen Shot 2015-09-12 at 11.22.26

Here I’m using Brontosaurus, which is among the more extreme apatosaurs, but the same features are seen developed to nearly the same extent in Apatosaurus louisae, the best-known apatosaur, and to some extent in all apatosaurs.

Now we’ll look at the four key features separately.

Screen Shot 2015-09-12 at 11.22.57

First, the cervicals ribs of sauropods (and other saurischians, including birds) anchored the longus colli ventralis and flexor colli lateralis muscles — ventral muscles whose job is to pull the neck downwards. By shifting the attachments points of these muscles downwards, apatosaurs enabled them to work with improved mechanical advantage — that is, to bring more force to bear.

Screen Shot 2015-09-12 at 11.23.06

Second, by redirecting the diapophyses and parapophyses ventrally, and making them much more robust than in other sauropods, apatosaurs structured their neck skeletons to better resist ventral impacts.

Screen Shot 2015-09-12 at 11.23.15

Third, because the low-hanging cervical ribs created an inverted “V” shape below the centrum, they formed a protective cradle for the vulnerable soft-tissue that is otherwise exposed on the ventral aspect of the neck: trachea, oesophagus, major blood vessels. In apatosaurus, all of these would have been safely wrapped in layers of connective tissue and bubble-wrap-like pneumatic diverticula. The presence of diverticula ventral to the vertebral centrum is not speculative – most neosauropods have fossae on the ventral surfaces of their cervical centra, and apatosaurines tend to have foramina that connect to internal chambers as well (see Lovelace et al. 2007: fig. 4, which is reproduced in this post).

Screen Shot 2015-09-12 at 11.23.22

Fourth, most if not all apatosaurs have distinctive ventrally directed club-like processes on the front of their cervical ribs. (It’s hard to tell with Apatosaurus ajax, because the best cervical vertebra of that species is so very reconstructed.) How did these appear in life? It’s difficult to be sure. They might have appeared as a low boss; or, as with rhinoceros horns, they might even have carried keratinous spikes.

Putting it all together, we have an animal whose neck can be brought downwards with great force; whose neck was mechanically capable of resisting impacts on its ventral aspect; whose vulnerable ventral-side soft-tissue was well protected; and which probably had prominent clubs or spikes all along the ventral aspect of the neck. And all of this was accomplished at the cost of making the neck a lot heavier than it would have been otherwise. Off the cuff, it seems likely that the cervical series alone would have massed twice as much in apatosaurines as in diplodocines of the same neck length.

Doubling the mass of the neck is a very peculiar thing for a sauropod lineage to do – by the Late Jurassic, sauropods were the leading edge of an evolutionary trend to lengthen and lighten the neck that had been running for almost 100 million years, through basal ornithodirans, basal dinosauromorphs, basal saurischians, basal sauropodomorphs, and basal sauropods. Whatever the selective pressures that led apatosaurines to evolve such robust and heavy necks, they must have been compelling.

The possibility that apatosaurs were pushing or crashing their necks ventrally in some form of combat accounts for all of the weird morphology documented above, and we know that sexual selection is powerful force that underlies a lot of bizarre structures in extant animals, and probably in extinct ornithodirans as well (see Hone et al. 2012, Hone and Naish 2013).

What form of combat, exactly? There are various possibilities, which we’ll discuss another time. But I’ll leave you with Brian Engh’s beautiful illustration of one possible form of combat: a powerful impact of one neck brought down onto the dorsal aspect of another.

ApatoNeckSmashRoughWeb

We’re aware that this proposal is necessarily somewhat speculative. But we’re just not able to see any other explanation for the distinctive apatosaur neck. Even if we’re wrong about the ventrolateral processes on the cervical ribs supporting bosses or spikes, the first three points remain true, and given how they fly in the face of sauropods’ long history of making their necks lighter, they fairly cry out for explanation. If anyone has other proposals, we’ll be happy to hear them.

References

  • Hone, D. W., Naish, D., & Cuthill, I. C. (2012). Does mutual sexual selection explain the evolution of head crests in pterosaurs and dinosaurs?. Lethaia 45(2):139-156.
  • Hone, D. W. E., & Naish, D. (2013). The ‘species recognition hypothesis’ does not explain the presence and evolution of exaggerated structures in non‐avialan dinosaurs. Journal of Zoology 290(3):172-180.
  • Lovelace, D. M., Hartman, S. A., & Wahl, W. R. (2007). Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527-544.

Fighting apatosaur art #1: Brian Engh

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In putting together our thoughts on how apatosaurs used their necks, we were motivated by genuine curiosity — which in Matt’s and my case, at least, goes back many years. (We briefly discussed the problem, if only to throw our hands up in despair, in our 2013 neck-anatomy paper.) We didn’t land on the combat hypothesis because it’s cool, but because it’s where the evidence points.

That said, it is cool.

Brian Engh is on the authorship for this paper largely because of his insights into extant animal behaviour. But there’s no denying that it’s a real bonus that he’s also an awesome artist. He’s been putting together sketches to illustrate our hypothesis for some time, partly with the goal of figuring out which compositions to work up into finished pieces. Here, with Brian’s permission, are some of those preliminary sketches.

First, a really nice sketch showing a ventral-to-ventral shoving match from down at ground level.

ApatoShove-Dutch-Web2

I really like this one, and would have been happy for it to be one of the anointed ones. I like the sense of huge beasts towering over the viewer. That said, I always love pencil sketches, often more than I do finished pieces, so I’m not too unhappy that the world gets to see this one in pencil-sketch form.

Next up, sketched more roughly, is a concept for a different form of combat in a different aspect. Here, we see two animals side by side, wrestling with both necks and tails.

Tail_and_Neck_Wrastling

I like the dynamism of this one, and especially that the one on the right is in the process of being pushed over. But there’s nothing in apatosaur tail morphology that particularly says “combat”, so I guess I’m not too unhappy that this one didn’t make the cut.

The third sketch shows two individuals rearing into into ventral-to-ventral push.

FatneckShoveMatch

Matt and Brian liked this one the most, so it got worked up into a finished and coloured piece which will be one of the figures in the paper when we get around to submitting it. Here is the current version — as I understand it, Brian plans to revise it further before it’s done.

ApatoNeckinWebUnmodified

The craftsmanship here is superb, but I can’t help regretting that the dinosaurs are rearing less than in the sketch. I feel it’s lost some of the power of the concept sketch.

What you’re seeing here, folks, is a bona fide instance of co-authors disagreeing. Happens all the time, but you usually don’t see it, because it’s all resolved by the time the paper is submitted. Brian is the artist, and ultimately it’s for him to decide what to depict and how; but I’ll always be glad that we still have the pencil-sketch as well as the finished version.

 


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