In writing the recent preprint “Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur” (Taylor 2017), it was invaluable to have a 3D model of the Xenoposeidon vertebra available. Here’s a short clip of viewing the model in the free MeshLab program. (It’s well worth full-screening to get the full impact.)

As I pan around, I look first at the upper margin of the posterior articular facet of the centrum, showing how the posterior margin of the neural arch shades into it — something that is not really apparent from photos, but needs the shifting perspectives that 3D offers to eliminate the interpretation that this contiguous border is due to damage.

Then I zoom in on the complex of laminae at the top of the left side of the neural arch, and explore the shapes of the intersections (ACPL with lateral CPRL, and PCDL with CPOL).

Finally I look at the distinctive sets of laminae on the anterior face of the vertebra which enclose the big, teardrop shaped centroparapophyseal fossa: lateral CPOL coming in from the lateral face of the arch, medial CPOL emerging from the pedicels, and the additional arched laminae that bound the space.

It’s just great to be able to do this. Time and again as I was preparing that manuscript, I went back to the model to check some detail — much as, twenty years earlier, Matt kept driving into the OMNH late at night to look at the Sauroposeidon holotype, to check out some idea he’d had as he worked on the description. The difference is, I didn’t need to drive into Norman, Oklahoma — or even London, England. The idea now of going back to trying to understand fossils from photos seems ridiculous.

A few years back, Matt wrote:

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.

I’m totally on board with that, and said as much in the concluding paragraph of the new preprint.

The last thing I want to say here is to acknowledge the enormous amount of help I’ve had from Heinrich Mallison, digitizer extraordinaire at the Museum für Naturkunde Berlin. He’s invested many, many hours building models for me from my photos, pointing me to programs that I can use to view them, and helping me get started on making my own models. The greatest regret of my palaeontological life is that, when I happened to be in Berlin on 19th November 2008 and Heinrich invited me to come and watch the Germany-England friendly at his place, I couldn’t do it, and missed out on a pretty unique chance to see England beat Germany, in Germany, with a German. I doubt that chance will come up again any time soon.

I leave you with EmperorDinobot‘s life restoration of Xenoposeidon, which I stumbled across a few days ago. Obviously it’s wildly speculative, but I’m cool with that.

References

  • Taylor, Michael P. 2017. Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur. PeerJ PrePrints 5:e3415. doi: 10.7287/peerj.preprints.3415 [PDF] [PeerJ page]

 

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I floated this idea on Fist Full of Podcasts, and Andrew Stuck gave it a shout-out in the comments, so I’m promoting it to a post.

The idea, briefly, is that sauropods grew fast and had enormous energy demands and even though horsetails and pine needles are surprisingly nutritious (Hummel et al. 2008), they probably suck to eat all the time. Extant herbivores are notoriously carnivorous when no-one is looking, and it’s silly to assume that extinct ones were any different. It seems likely that a big, hungry sauropod, gifted by natural selection with more selfish opportunism than compassion, would probably have viewed a turtle as a quick shot of protein and calcium, and a welcome hors d’oeuvre before stripping yet another conifer or tree fern. Furthermore, said sauropod would have been well-equipped to render the unfortunate chelonian into bite-size chunks, as shown above. The first time might even have been accidental. (Yeah, sure, Shunosaurus, I believe you. [rolls eyes])

Given that sauropods and turtles coexisted over most of the globe for most of the Mesozoic, I’ll bet this happened all the time. I don’t know how to falsify that,* but how could it not have? You’d have to assume that sauropods didn’t run into turtles, or that their mercy outweighed their curiosity and hunger. That’s even more bonkers than turtle nachos.** As Sherlock Holmes almost said, “When you have eliminated the impossible, whatever remains – no matter how stupid/awesome – was probably done by sauropods.”

* “Oh, you found a boatload of turtle shell pieces at your fossil site? How tantalizingly unprecedented – please tell me more!” said no-one ever. Seriously, everyone who works on stuff younger than the Early Jurassic seems to bitch about all of the turtle frags they find, whether they’re looking for Apatosaurus or Australopithecus.

** Not to be all navel-gazey, but that is conservatively the greatest sentence I have ever written.

In conclusion, sauropods stomped on turtles and ate them, because duh. Fight me.

Further Reading

For more sauropods stomping, see:

And for sauropods not eating, but gettin’ et:

Reference

Hummel, J., Gee, C. T., Südekum, K. H., Sander, P. M., Nogge, G., & Clauss, M. (2008). In vitro digestibility of fern and gymnosperm foliage: implications for sauropod feeding ecology and diet selection. Proceedings of the Royal Society of London B: Biological Sciences, 275(1638), 1015-1021.

 

 

Cryptic Aquilops, by Brian Engh. Available as a poster print – see below.

One of the many nice things about getting to help name new taxa is that once you let them out into the world, other people can unleash their considerable talents on ‘your’ critters. Which means that every now and then, something cool pops up that you have a deep personal connection to. Things have been fairly quiet on the Aquilops front for a while, and all of a sudden I have news.

I’m still waiting for a plush Aquilops – c’mon, Homo sapiens, how has this not happened already? – but if you’d like a life-size Aquilops in bronze, sculptor James Herrmann has you covered. James got in touch with me last fall when the project was just in the planning stages. His timing was excellent – I’d just seen the presentation on camouflage in Psittacosaurus at SVPCA, and the paper by Vinther et al. was out a week or two later. I sent James some papers and photos of dead animals, he sent back photos of the work in progress, and now his Aquilops is done.

About the sculpture, James writes:

I am offering the sculpture for sale as a limited edition of 25.  The sculpture is life sized, it is approximately 60 lbs and is 33″L x 14”H x 11”W.  The price I am asking for it is $4500.  I am getting a slab of green soapstone for the base although it does display well without the stone so it will be bolted on from below and not epoxied. […] The gingko leaves and log part of the sculpture were made from molds taken from plants growing locally.

I dig it. If you’re interested in getting one, please visit his website, HerrmannStudio.com.

Aquilops ’14. I was there, man. It was crazy. A Brian Engh joint.

Next item: back in 2014, Brian Engh created the public face of Aquilops with the wonderful graphic art he did for the paper and the press release. Now he’s gone back to the well and reimagined Aquilops, based in part on what we know of its paleoecology – that’s the image at the top of the post. He explains his new view of Aquilops in a thoughtful and wide-ranging video on his paleoart YouTube channel. (If you miss his rap videos set in the Daikaijucene, he also has a YouTube channel for music and monsters. And a blog. And a Patreon page. You get the picture.) You should also check out the two-part interview with Brian at the PLOS Paleo Community blog (part 1, part 2).

Here’s the aforementioned video:

Poster prints of Aquilops Classic and Next Gen can be purchased through Brian’s website, DontMessWithDinosaurs.com.

Finally, a couple of older Aquilops-themed art things that I didn’t cover when they happened. Lead author Andy Farke is also an award-winning homebrewer and he concocted his Eagle Face Oatmeal Stout in honor of our little buddy. He has lots more beer-and-dinosaur crossover goodness on his brewing blog – check it out.

Last fall artist Natalie Metzger did a bunch of drawings of extant animals wearing the skulls of extinct animals for Inktober. In the very first batch was this awesome squirrel looking unexpectedly badass in an Aquilops skull. I don’t know what it means, but I would totally play that D&D campaign. Natalie has a bunch more cool stuff on her blog and Patreon page, and she’ll be at the Rose City Comic Con in Portland this September, so go say hi and buy her art.

Really finally, I am not on Twitter – trust me, I don’t need less of a filter between my occasional stupidity and the world – but for all the rest of you, keep an eye on #Aquilops and, if you’re a heartless jerk, #Aquilopsburrito.

Have more Aquilops stuff I haven’t covered but should? The comment field is open.

References

I imagine that by now, everyone who reads this blog is familiar with Mark Witton’s painting of a giant azhdarchid pterosaur alongside a big giraffe. Here it is, for those who haven’t seen it:

Arambourgiania vs giraffe vs the Disacknowledgement redux Witton ver 2 low res

(This is the fifth and most recent version that Mark has created, taken from 9 things you may not know about giant azhdarchid pterosaurs.)

It’s one of those images that really kicks you in the brain the first time you see it. The idea that an animal the size of a giraffe could fly under its own power seems ludicrous — yet that’s what the evidence tells us.

But wait — what do we mean by “an animal the size of a giraffe”? Yes, the pterosaur in this image is the same height as the giraffe, but how does its weight compare?

Mark says “The giraffe is a big bull Masai individual, standing a healthy 5.6 m tall, close to the maximum known Masai giraffe height.” He doesn’t give a mass, but Wikipedia, citing Owen-Smith (1988), says “Fully grown giraffes stand 5–6 m (16–20 ft) tall, with males taller than females. The average weight is 1,192 kg (2,628 lb) for an adult male and 828 kg (1,825 lb) for an adult female with maximum weights of 1,930 kg (4,250 lb) and 1,180 kg (2,600 lb) having been recorded for males and females, respectively.” So it seems reasonable to use a mass intermediate between those of an average and maximum-sized male, (1192+1930)/2 = 1561 kg.

So much for the giraffe. What does the azhdarchid weigh? The literature is studded with figures that vary wildly, from the 544 kg that Henderson (2010) found for Quetzalcoatlus, right down to the widely cited 70 kg that Chatterjee and Templin (2004) found for the same individual — and even the astonishing 50 kg that seems to be favoured by Unwin (2005:192). In the middle is the 259 kg of Witton (2008).

It occurred to me that I could visualise these mass estimates by shrinking the giraffe in Mark’s image down to the various proposed masses, and seeing how credible it looks to imagine these reduced-sized giraffes weighting the same as the azhdarchid. The maths is simple. For each proposed azhdarchid mass, we figure out what it is as a proportion of the giraffe’s 1561 kg; then the cube root of that mass proportion gives us the linear proportion.

  • 544 kg = 0.389 giraffe masses = 0.704 giraffe lengths
  • 259 kg = 0.166 giraffe masses = 0.549 giraffe lengths
  • 70 kg =0.0448 giraffe masses = 0.355 giraffe lengths

Let’s see how that looks.

Arambourgiania vs giraffe vs the Disacknowledgement redux Witton ver 2 low res

On the left, we have Mark’s artwork, with the giraffe massing 1561 kg. On the right, we have three smaller (isometrically scaled) giraffes of masses corresponding to giant azhdarchid mass estimates in the literature. If Don Henderson (2010) is right, then the pterosaur weighs the same as the 544 kg giraffe, which to me looks pretty feasible if it’s very pneumatic. If Witton (2008) is right, then it weighs the same as the 259 kg giraffe, which I find hard to swallow. And if Chatterjee and Templin (2004) are right, then the giant pterosaur weighs the same as the teeny tiny 70 kg giraffe, which I find frankly ludicrous. (For that matter, 70 kg is in the same size-class as Georgia, the human scale-bar: the idea that she and the pterosaur weigh the same is just silly.)

What is the value of such eyeball comparisons? I’m not sure, beyond a basic reality check. Running this exercise has certainly made me sceptical about even the 250 kg mass range which now seems to be fairly widely accepted among pterosaur workers. Remember, if that mass is correct then the pterosaur and the 259 kg giraffe in the picture above weight the same. Can you buy that?

Or can we find extant analogues? Are there birds and mammals with the same mass that are in the same size relation as these images show?

References

  • Chatterjee, Sankar, and R. J. Templin. 2004. Posture, locomotion, and paleoecology of pterosaurs. Geological Society of America, Special Paper 376. 68 pages.
  • Henderson, Donald M. 2010. Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology 30(3):768-785.
  • Witton, Mark P. 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana 28:143-159.

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.
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]

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