Alexandre Fabre recently bought a French-language comic-book, Les Dinosaures by Plumeri and Bloz, and found this in the third volume:

The text reads:

Et parfois, les paléontologues font des announces très marrantes, comme le Brontomerus

… un sauropode aux jambes musclées … qui se défendrait en donnant des coups de pied!

“Aie! Un dino qui fait de kung-fu? Ils ne savent plus quoi inventer!”

Which I roughly translate as:

And sometimes, paleontologists make very funny announcements, such, as Brontomerus …

A sauropod with muscular legs … which defends itself by kicking!

“Ouch! A dino that does kung-fu? Whatever will they think of next!”

Many thanks to Alexandre for bringing it to my attention and scanning the relevant panels.

Posting palaeo papers on arXiv

September 28, 2012

Over on Facebook, where Darren posted a note about our new paper, most of the discussion has not been about its content but about where it was published. We’re not too surprised by that, even though we’d love to be talking about the science. We did choose arXiv with our eyes open, knowing that there’s no tradition of palaeontology being published there, and wanting to start a new tradition of palaeontology being routinely published there. Having now made the step for the first time, I see no reason ever to not post a paper on arXiv, as soon as it’s ready, before — or maybe even instead of — submitting it to a journal.

(Instead of? Maybe. We’ll discuss that below.)

The key issue is this: science isn’t really science until it’s out there where it can be used. We wrote the bulk of the neck-anatomy paper back in 2008 — the year that we first submitted it to a journal. In the four years since then, all the observations and deductions that it contains have been unavailable to the world. And that is stupid. The work might just as well never have been done. Now that it’s on arXiv, that’s over. I was delighted to get an email less than 24 hours after the paper was published, from an author working on a related issue, thanking us for posting the paper, saying that he will now revise his own in-prep manucript in light of its findings, and cite our paper. Which of course is the whole point: to get our science out there where it can do some damage.

Because the alternative is horrible, really. Horribly wasteful, horribly dispiriting, horribly retarding for science. For example, a couple of weeks ago in his SVPCA talk, David Norman was lamenting again that he never got around to publishing the iguanodont systematic work that was in his dissertation, I-don’t-know-how-many-years-ago. The result of that interminable delay is that others have done other, conflicting iguanodont systematic work, and Norman is now trying belatedly to undo that and bring his own perspective. A terrible an unnecessary slowing of ornithopod science, and a waste of duplicated effort. (Thankfully it’s only ornithopods.)

And of course David Norman is very far from being alone. Pretty much any palaeontologist you talk to will tell you of a handful of papers — many more in some cases — that were finished many years previously but have never seen the light of day. (I still have a couple myself, but there is no point in resurrecting them now because progress has overtaken them.) I wonder what proportion of all Ph.D work ever sees the light of day? Half? Less? It’s crazy.

Figure 8. Sauropod cervical vertebrae showing anteriorly and posteriorly directed spurs projecting from neurapophyses. 1, cervical 5 of Sauroposeidon holotype OMNH 53062 in right lateral view, photograph by MJW. 2, cervical 9 of Mamenchisaurus hochuanensis holotype CCG V 20401 in left lateral view, reversed, from photograph by MPT. 3, cervical 7 or 8 of Omeisaurus junghsiensisYoung, 1939 holotype in right lateral view, after Young (1939, figure 2). (No specimen number was assigned to this material, which has since been lost. D. W. E. Hone personal communication, 2008.)

Publish now, publish later

So, please folks: we all need to be posting our work on preprint servers as soon as we consider it finished. It doesn’t mean that the posted versions can’t subsequently be obsoleted by improved versions that have gone through peer-review and been published in conventional journals. But it does mean that the world can know about the work, and build on it, and get the benefit of it, as soon as it’s done.

You see, we have a very fundamental problem in academia: publishing fulfils two completely separate roles. Its primary role (or at least the role that should be primary) is to make work available to the community; the secondary role is to provide a means of keeping score — something that can be used when making decisions about who to appoint to jobs, when to promote, who gets grants, who gets tenure and so on. I am not going to argue that the latter shouldn’t happen at all — clearly a functioning community needs some way to infer the standing of its participants. But I do think it’s ridiculous when the bean-counting function of publication trumps the actual publication role of publication. Yet we’ve all been in a position where we have essentially complete work that could easily go on a blog, or in the PalAss newsletter, or in a minor journal, or somewhere — but we hang onto it because we want to get it into a Big Journal.

Let me say again that I do realise how unusual and privileged my own position is: that a lot of my colleagues do need to play the Publication Prestige game for career reasons (though it terrifies my how much time some colleagues waste squeezing their papers into two-and-a-half-page format in the futile hope of rolling three sixes on the Science ‘n’ Nature 3D6). Let’s admit right now that most palaeontologists do need to try to get their work into Proc B, or Paleobiology, or what have you. Fair enough. They should feel free. But the crucial point is this: that is no reason not to post pre-prints so we can all get on with actually benefitting from your work in the mean time.

Actually, I feel pretty stupid that it’s taken me this long to realise that all my work should go up on arXiv.

Figure 11. Archosaur cervical vertebrae in posterior view, Showing muscle attachment points in phylogenetic context. Blue arrows indicate epaxial muscles attaching to neural spines, red arrows indicate epaxial muscles attaching to epipophyses, and green arrows indicate hypaxial muscles attaching to cervical ribs. While hypaxial musculature anchors consistently on the cervical ribs, the principle epaxial muscle migrate from the neural spine in crocodilians to the epipophyses in non-avial theropods and modern birds, with either or both sets of muscles being significant in sauropods. 1, fifth cervical vertebra of Alligator mississippiensis, MCZ 81457, traced from 3D scans by Leon Claessens, courtesy of MCZ. Epipophyses are absent. 2, eighth cervical vertebra ofGiraffatitan brancai paralectotype HMN SII, traced from Janensch (1950, figures 43 and 46). 3, eleventh cervical vertebra of Camarasaurus supremus, reconstruction within AMNH 5761/X, “cervical series I”, modified from Osborn and Mook (1921, plate LXVII). 4, fifth cervical vertebra of the abelisaurid theropod Majungasaurus crenatissimus,UA 8678, traced from O’Connor (2007, figures 8 and 20). 5, seventh cervical vertebra of a turkey, Meleagris gallopavo, traced from photographs by MPT.

Exceptions?

So are there any special cases? Any kinds of papers that we should keep dry until they make it into actual journals? I can think of two classes that you could argue for — one of them convincingly, the other not.

First, the unconvincing one. When I discussed this with Matt (and half the fun of doing that is that usually neither of us really knows what we think about this stuff until we’re done arguing it through), he suggested to me that we couldn’t have put the Brontomerus paper on arXiv, because that would have leaked the name, creating a nomen nudum. My initial reaction was to agree with him that this is an exception. But when I thought about it a bit more, I realised there’s actually no compelling reason not to post such a paper on arXiv. So you create a nomen nudum? So what? Really: what is the negative consequence of that? I can’t think of one. OK, the name will appear on Wikipedia and mailing lists before the ICZN recognises it — but who does that hurt? No-one that I can think of. The only real argument against posting is that it could invite scooping. But is that a real threat? I doubt it. I can’t think of anyone who would be barefaced enough to scoop a taxon that had already been published on arXiv — and if they did, the whole world would know unambiguously exactly what had happened.

So what is the one real reason not to post a preprint? I think that might be a legitimate choice when publicity needs to be co-ordinated. So while nomenclatural issues should not have stopped us from arXiving the Brontomerus paper, publicity should. In preparation for that paper’s publication day, we did a lot of careful work with the UCL publicity team: writing non-specialist summaries, press-releases and FAQs, soliciting and preparing illustrations and videos, circulating materials under embargo, and so on. In general, mainsteam media are only interested in a story if it’s news, and that means you need to make sure it’s new when they first hear about it. Posting the article in advance on a publicly accessible archive would mess that up, and probably damage the work’s coverage in the press, TV and radio.

Publication venues are a continuum

It’s become apparent to us only gradually that there’s really no clear cut-off where a paper becomes “properly published”. There’s a continuum that runs from least to most formal and exclusive:

SV-POW! — arXiv — PLOS ONE — JVP — Nature

1. On SV-POW!, we write what we want and publish it when we want. We can promise you that it won’t go away, but you only have our word for it. But some of what we write here is still science, and has been cited in papers published in more formal venues — though, as far as I know, only by Matt and me so far.

2. On arXiv, there is a bit more of a barrier to clear: you have to get an existing arXiv user to endorse your membership application, and each article you submit is given a cursory check by staff to ensure that it really is a piece of scientific research rather than a diary entry, movie review or spam. Once it’s posted, the paper is guaranteed to remain at the same URL, unchanged, so long as arXiv endures (and it’s supported by Cornell). Crucially, the maths, physics and computer science communities that use arXiv uncontroversially consider this degree of filtering and permanence sufficient to constitute a published, citeable source.

3. At PLOS ONE, your paper only gets published if it’s been through peer-review — but the reviewing criteria pertain only to scientific soundness and do not attempt to evaluate likely impact or importance.

4. At JVP and other conventional journals, your paper has to make it through a two-pronged peer-review process: it has to be judged both sound scientifically (as at PLOS ONE) and also sufficiently on-topic and important to merit appearing in the journal.

5. Finally, at Nature and Science, your paper has to be sound and be judged sexy — someone has to guess that it’s going to prove important and popular.

Where along this continuum does the formal scientific record begin? We could make a case that all of it counts, provided that measures are taken to make the SV-POW! posts permanent and immutable. (This can be done submitting them to WebCite or to a service such as Nature Precedings used to provide.) But whether or not you accept that, it seems clear that arXiv and upwards is permanent, scientific and citeable.

This raises an interesting question: do we actually need to go ahead and publish our neck-anatomy paper in a more conventional venue? I’m honestly not sure at the moment, and I’d be interested to hear arguments in either direction. In terms of the progress of science, probably not: our actual work is out there, now, for the world to use as it sees fit. But from a career perspective, it’s probably still worth our while to get it into a journal, just so it can sit more neatly on our publication lists and help Matt’s tenure case more. And yet I don’t honestly expect any eventual journal-published version to be better in any meaningful way than the one on arXiv. After all, it’s already benefitted from two rounds of peer-review, three if you count the comments of my dissertation examiners. More likely, a journal will be less useful, as we have to cut length, eliminate illustrations, and so on.

So it seems to me that we have a hard choice ahead of us now. Call that paper done and more onto making more science? Or spend more time and effort on re-publishing it in exchange for prestige? I really don’t know.

For what it’s worth, it seems that standard practice in maths, physics and computer science is to republish arXiv articles in journals. But there are some scientists who routinely do not do this, instead allowing the arXiv version to stand as the only version of record. Perhaps that is a route best left to tenured greybeards rather than bright young things like Matt.

Figure 5. Simplified myology of that sauropod neck, in left lateral view, based primarily on homology with birds, modified from Wedel and Sanders (2002, figure 2). Dashed arrows indicate muscle passing medially behind bone. A, B. Muscles inserting on the epipophyses, shown in red. C, D, E. Muscles inserting on the cervical ribs, shown in green. F, G. Muscles inserting on the neural spine, shown in blue. H. Muscles inserting on the ansa costotransversaria (“cervical rib loop”), shown in brown. Specifically: A. M. longus colli dorsalis. B. M. cervicalis ascendens. C. M. flexor colli lateralis. D. M. flexor colli medialis. E. M. longus colli ventralis. In birds, this muscle originates from the processes carotici, which are absent in the vertebrae of sauropods. F. Mm. intercristales. G. Mm. interspinales. H. Mm. intertransversarii. Vertebrae modified from Gilmore (1936, plate 24).

Citing papers in arXiv

Finally, a practicality: since it’ll likely be a year or more before any journal-published version of our neck-anatomy paper comes out, people wanting to use it in their own work will need to know how to cite a paper in arXiv. Standard procedure seems to be just to use authors, year, title and arXiv ID. But in a conventional-journal citation, I like the way that the page-range gives you a sense of how long the paper is. So I think it’s worth appending page-count to the citations. And while you’re at it, you may as well throw in the figure and table counts, too, yielding the version that we’ve been using:

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

YPM 5449, a posterior dorsal vertebra of Sauroposeidon, from D’Emic and Foreman (2012:fig. 6A and C).

Another recent paper (part 1 is here) with big implications for my line of work: D’Emic and Foreman (2012), “The beginning of the sauropod dinosaur hiatus in North America: insights from the Lower Cretaceous Cloverly Formation of Wyoming.” In it, the authors sink Paluxysaurus into Sauroposeidon and refer a bunch of Cloverly material to Sauroposeidon as well. So in one fell swoop Sauroposeidon goes from being one of the most poorly represented Early Cretaceous North American sauropods, based on just four vertebrae from a single individual, to one of the best-known, most complete, and most widespread, based on at least seven individuals from Texas, Oklahoma, and Wyoming.

The web of connections among the different sets of material is complex, and involves the Sauroposeidon holotype OMNH 53062 from the Antlers Formation of southeastern Oklahoma, the type and referred material of Paluxysaurus from the Twin Mountains Formation of northern Texas described by Rose (2007), sauropod material from the Cloverly Formation of north-central Wyoming described and illustrated by Ostrom (1970), and UM 20800, a scap and coracoid newly excavated from one of Ostrom’s old quarries.  D’Emic and Foreman argue that (1) the Cloverly material is referable to Sauroposeidon based on the shared derived characters of a juvenile cervical, YPM 5294, and the Sauroposeidon holotype, and (2) Paluxysaurus is not distinguishable from the Cloverly material and in fact shares several autapomorphies with the Cloverly sauropod. Which means that (3) Paluxysaurus is Sauroposeidon.

But that’s not all! All the new material suggests different phylogenetic affinities for Sauroposeidon. Instead of a brachiosaurid, it is now posited to be a basal somphospondyl. That’s not super-surprising; as we noted back in 2000 (Wedel et al. 2000), if Sauroposeidon was a brachiosaurid it had evolved some features in parallel with titanosaurs, most notably the fully camellate internal structure of the cervical vertebrae. And it also makes sense because other basal somphospondyls include Erketu and Qiaowanlong, the cervicals of which are similar to Sauroposeidon in some features. D’Emic and Foreman (2012) cite a forthcoming paper by Mike D’Emic in the Journal of Systematic Paleontology that contains the cladistic analysis backing all this up, but the case based on comparative anatomy is already pretty strong.

If anyone is unconvinced by all of these referrals, please bear in mind that we haven’t heard the whole story yet, quite probably for reasons that are outside of the authors’ control.  I am inclined to be patient because I have been in that situation myself: Wedel (2003a) was intended to stand on the foundation of evidence laid down by Wedel (2003b), but because of the vagaries of publication schedules at two different journals, the interpretive paper beat the descriptive one into press by a couple of months.

Mid-cervical originally described as Paluxysaurus, now referred to Sauroposeidon, from Rose (2007:fig. 10).

Anyway, if anyone wants my opinion as “Mr. Sauroposeidon“, I think the work of D’Emic and Foreman (2012) is solid and the hypothesis that Paluxysaurus is Sauroposeidon is reasonable. So, if I think it’s reasonable now, why didn’t I synonymize the two myself? Partly because I thought there was a pretty good chance the two were not the same, based mostly on FWMSH 93B-10-8 (which I referred to as FWMSH “A” in Wedel 2003b, since I had only seen in on display without a specimen number), which I thought looked a lot more like a titanosaur cervical than a brachiosaur cervical. But of course I thought Sauroposeidon was a brachiosaur until a couple of months ago, and if it ain’t, and if brachiosaurs and basal somphospondyls have similar cervicals, that objection is considerably diminished. And partly because I’ve had other things to be getting on with, and stopping everything else to spend what would realistically be a few months looking into a possible synonymy (that I didn’t strongly suspect) wasn’t feasible in terms of time or geography. So I’m glad that D’Emic and Foreman have done that work, and I’m excited about the new things they’ve uncovered.

And I’m honored to bring you a new life restoration of Sauroposeidon by uber-talented Bob Nicholls, which we think is the first to show Sauroposeidon in its new guise as a basal somphospondyl. Click through for the mega-awesome version.

Same critter, different views. If anyone wants to GDI this baby, you now have everything you need. Many thanks to Bob for permission to post these and the following making-of images. Please visit him at Paleocreations.com to see a ton of awesome stuff, and give him some love–or at least a few thousand “likes”–on Facebook.

This is Bob’s first foray into 3D modeling, but you’d never know from the quality of his virtual sculpt. And let me tell you, that dude works fast. He sent this initial version, showing Sauroposeidon as an attenuated brachiosaur (sorta like this) on August 23, to solicit comments from Mike and me.

I wrote back and let Bob know about the new work of D’Emic and Foreman, and suggested that he could probably be the first to restore Sauroposeidon as a somphospondyl. Mike and I also voiced our opposition to the starvation-thinned neck, and Mike suggested that the forelimb was too lightly muscled and that the ‘fingers’ were probably too prominent. The very next day, this was in our inboxes:

I wrote back:

Whatever Sauroposeidon was, its neck was fairly tall and skinny in cross-section. It looks like the neck on your model sort of tapers smoothly from the front of the body to the head. I think it would be much narrower, side-to-side, along most of its length, and would have a more pronounced shoulder-step where it met the body.
The bottom view is very useful. It shows the forefeet as being about the same size as the hindfeet. AFAIK all or nearly all known sauropod tracks have much bigger hindfeet than forefeet. Certainly that is the case with Brontopodus birdi, the big Early Cretaceous sauropod tracks from Texas that were probably made by Sauroposeidon. The forefeet should be about 75-80% the width of the hindfeet, and only about half a long front-to-back. Even if you don’t quite get to those numbers, shrinking the forefeet a bit and subtly up-sizing the hindfeet would make the model more accurate.
Mike’s commentary was much shorter–and funnier:
I like how freaky it looks. It looks WRONG, but in a good way.
Bob toiled over the weekend and came back with this subtly different, subtly better version:

I had one more change to recommend:

I’m sorry I didn’t suggest this sooner, but it only just now occurred to me. With the referral of Paluxysaurus and the Cloverly material to Sauroposeidon, we now have dorsal vertebrae, and they are loooong, much more similar in proportion to the dorsals of Brachiosaurus altithorax than those of Giraffatitan brancai. So, as much as I like the compact little body on your Sauroposeidon, I think it was probably fairly long in the torso. You probably already have Mike’s Brachiosaurus paper [Taylor 2009] with the skeletal recon showing the long torso–in the absence of an updated skeletal recon for Sauroposeidon, I’d use Mike’s Figure 7 as a guide for reconstructing the general body proportions.

Bob lengthened the torso to produce the final version, which is the first one I showed above. He sent that over on August 29–the delay in getting this post up rests entirely with me.

So. It is still very weird to think of “my” dinosaur as a somphospondyl rather than a brachiosaur. I had 15 years to get used to the latter idea. But suddenly having a lot more material–essentially the whole skeleton, minus some stinkin’ skull bits–is pretty darned exciting, and the badass new life restoration doesn’t hurt, either.

Now, would it be too much to wish for some more Brontomerus?

References

Last time, we saw why Haplocanthosaurus couldn’t be a juvenile of Apatosaurus or Diplodocus, based on osteology alone.  But there’s more:

Ontogenetic status of Haplocanthosaurus

Here is where is gets really surreal.  Woodruff and Fowler (2012) blithely assume that Haplocanthosaurus is a juvenile of something, but the type specimen of the type species — H. priscus CM 572 — is an adult.  As Hatcher (1903:3) explains:

The type No. 572 of the present genus consists of the two posterior cervicals, ten dorsals, five sacrals, nineteen caudals, both ilia, ischia and pubes, two chevrons, a femur and a nearly complete series of ribs, all in an excellent state of preservation and pertaining to an individual fully adult as is shown by the coössified neural spines and centra.

So far as I can see, Woodruff and Fowler are confused because the second species that Hatcher describes, H. utterbacki, is based on the subadult specimen CM 879.  Where possible in the previous post, I have used illustrations of the adult H. priscus, so that the comparisons are of adult with adult.  The exceptions are the two anterior cervicals and the first dorsal, which are known only from H. utterbacki.  And sure enough, if you look closely at the illustrations, you can see that in these vertebrae and only these vertebrae, Hatcher had the neurocentral junction illustrated — because it wasn’t yet fused.

Haplocanthosaurus posterior, mid and anterior cervical vertebrae, C14, C9 and C4, in right lateral view. C14 of adult H. priscus (from Hatcher 1903:plate I); C9 and C4 of H. utterbacki (from plate II). Red ellipses highlight neurocentral sutures.

As it happens, the difference in ontogenetic status between these two specimens is nicely illustrated by Wedel (2009), although he was only in it for the pneumaticity:

Neurocentral fusion in Haplocanthosaurus. A, B. Posterior cervical vertebra C?12 of sub-adult H. utterbacki holotype CM 879: A, X-ray in right lateral view; B, coronal CT slice showing separate ossificaton of centrum and neural arch. C, D. Mid-dorsal vertebra D6 of adult H. priscus holotype CM 572: X-rays in (A) right lateral and (B) anterior view, showing fully fused neural arch. Wedel (2009:fig. 6)

So H. utterbacki CM 879 certainly is an immature form of something; and that something is Haplocanthosaurus, most likely H. priscus.  (The characters which Hatcher used to separate the two species are not particularly convincing.)

With that out the way, we can move on to …

Phylogenetic analysis

A simple way to evaluate the parsimony or otherwise of a synonymy is to use a phylogenetic analysis. In their abstract, Woodruff and Fowler claim that “On the basis of shallow bifurcation of its cervical and dorsal neural spines, the small diplodocid Suuwassea is more parsimoniously interpreted as an immature specimen of an already recognized diplodocid taxon”.  Without getting into the subject of Suuwassea again — Matt pretty much wrapped that up in part 4 — the point here is that the word “parsimony” has a particular meaning in studies of evolution: it refers to minimising the number of character-state changes.  And we have tools for measuring those.

So let’s use parsimony to evaluate the hypothesis that Haplocanthosaurus is one of the previously known diplodocids.  Pretending for the moment that Haplocanthosaurus really was known only from subadults, how many additional steps would we need to account for if ontogeny were to change its position to make it group with one of the diplodocids?

You don’t need to be a cladistics wizard to do this.  (Which is handy, since I am not one.)  Here’s the method:

  • Start with an existing matrix, add constraints, re-run it, and see how the tree-length changes.  Since I am familiar with it, I started with the matrix from my 2009 paper on brachiosaurs.
  • Re-run the matrix to verify that you get the same result as in the published paper based on it.  This gives you confidence that you’re running it right.  In this case, I got a minimum tree length of 791 steps, just as in Taylor (2009).
  • Add extra instructions to the run-script defining and imposing constraints.  Note that you do not have to mess with the characters, taxa or codings to do this.
  • Run the matrix again, with the constraint in place, and see how the tree-length changes.
  • Repeat as needed with other constraints to evaluate other phylogenetric hypotheses.

(This is how we produced the part of the Brontomerus paper (Taylor et al. 2011:89) where we said “One further step is sufficient to place Brontomerus as a brachiosaurid, a basal (non−camarasauromorph) macronarian, a basal (non−diplodocid) diplodocoid or even a non−neosauropod. Three further steps are required for Brontomerus to be recovered as a saltasaurid, specifically an opisthocoelicaudiine”.  And that’s why we weren’t at all dogmatic about its position.)

Anyway, going through this exercise with Haplocanthosaurus constrained in turn to be the sister taxon to Apatosaurus, Diplodocus, etc., yielded the following results:

  • (no constraint) —  791 steps
  • Apatosaurus — 817 (26 extra)
  • Diplodocus — 825 (34 extra)
  • Barosaurus — 815 (24 extra)
  • Camarasaurus — 793 (2 extra)
  • Brachiosaurus — 797 (6 extra)

(I threw in the other well-known Morrisson-Formation sauropods Camarasaurus and Brachiosaurus, even though Woodruff and Fowler don’t mention them, just because it was easy to do and I was interested to see what would happen.  And when I say Brachiosaurus, I mean B. altithorax, not Giraffatitan.)

I hope you’re as shocked as I am to see that for Haplocanthosaurus to emerge as the sister taxon of any diplodocid needs a minimum of 24 additional steps — or an incredible 34 for it to be sister to Diplodocus.  In other words, the hypothesis is grossly unparsimonious.  Of course, that doesn’t in itself mean that it’s false: but it does render it an extraordinary claim, which means that it needs extraordinary evidence.  And while “the simple spines of Haplocanthosaurus might bifurcate when it grows up” is extraordinary evidence, it’s not in the way that Carl Sagan meant it.

In short, running this simple exercise — it took me about a hour, mostly to remember how to do constraints in PAUP* — would have given Woodruff and Fowler pause for thought before dragging Haplocanthosaurus into their paper.

Oh, and it’s ironic that placing Haplo as sister to Brachiosaurus requires only a quarter as many steps as the closest diplodocid, and as sister to Camarasaurus requires only two steps.  If you really want to synonymise Haplocanthosaurus, Camarasaurus is the place to start.  (But don’t get excited, it’s not Camarasaurus either.  It’s Haplocanthosaurus.)

[By the way, anyone who’d like to replicate this experiment for themselves is welcome: all the files are available on my web-site.  You only really need the .nex file, which you can feed to PAUP*, but I threw in the log-file, the generated tree files and the summary file, too.  Extra Credit: run this same exercise to evaluate the parsimony of Suuwassea as a subadult of one of these other genera.  Report back here when you’re done to earn SV-POW! points.]

Conclusion

It’s a truism that we stand on the shoulders of giants.  In the case of sauropod studies, those giants are people like J. B. Hatcher, Charles Gilmore, Osborn and Mook and — bringing it up to date — John McIntosh, Paul Upchurch, Jeff Wilson and Jerry Harris.  When Hatcher described Haplocanthosaurus as a new genus rather than a subadult Diplodocus, he wasn’t naive.  He recognised the effects of ontogeny, and he was aware that one of his two specimens was adult and the other subadult.  He was also probably more familiar with Diplodocus osteology than anyone else has ever been before or since, having written the definitive monograph on that animal just two years previously (Hatcher 1901).

By the same token, people like Upchurch and Wilson have done us all a huge favour by making the hard yards in sauropod phylogenetics.  If we’re going to go challenging the standard consensus phylogeny, it’s just good sense to go back to their work (or the more recent work of others, such as Whitlock 2011), re-run the analyses with our pet hypotheses encoded as constraints, and see what they tell us.

So in the end, my point is this: let’s not waste our giants.  Let’s take the time to get up on their shoulders and survey the landscape from up there, rather than staying down at ground level and seeing how high we can jump from a standing start.

The rest of the series

Links to all of the posts in this series:

and the post that started it all:

 References

  • Hatcher, J.B. 1901. Diplodocus (Marsh): its osteology, taxonomy, and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63.
  • Hatcher, J.B. 1903. Osteology of Haplocanthosaurus with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds; additional remarks on Diplodocus. Memoirs of the Carnegie Museum 2:1-75.
  • Taylor, M.P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806.
  • Taylor, M.P., Wedel, M.J. and Cifelli, R.L. 2011. A new sauropod dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA. Acta Palaeontologica Polonica 56(1):75-98. doi:10.4202/app.2010.0073
  • Wedel, M.J. 2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A:611-628.
  • Whitlock, J.A. 2011. A phylogenetic analysis of Diplodocoidea (Saurischia: Sauropoda). Zoological Journal of the Linnean Society 161(4):872-915. doi: 10.1111/j.1096-3642.2010.00665.x
  • Woodruff, D.C, and Fowler, D.W. 2012. Ontogenetic influence on neural spine bifurcation in Diplodocoidea (Dinosauria: Sauropoda): a critical phylogenetic character. Journal of Morphology, online ahead of print.

As everyone now knows, last week the respected and trusted Today programme on BBC Radio 4 ran an absurd nonscience piece on Brian Ford’s wild, ignorant, uninformed speculation that all dinosaurs lived in shallow lakes because that was the only way they could support their weight.  Plenty of people have shown what utter, contemptible nonsense this is, and I won’t waste everyone’s time by reiterating it.

Inspired by a comment by Stephen Curry, I put together a request for a formal retraction, and solicited signatories from the VRTPALEO list and Dinosaur Mailing List during a 24-hour window.  During that time 20 palaontologists contacted me to sign, and so this is what I submitted at 3pm on Thursday 5th April:

Dear Radio 4,

The Today Programme for Tuesday 3rd April 2012 contained a science piece by Tom Feilden:
http://news.bbc.co.uk/today/hi/today/newsid_9710000/9710630.stm
regarding Professor Brian J. Ford’s “theory” that dinosaurs did not live on land but in shallow lakes which supported their weight.

Professor Ford’s theory was published in a magazine rather than a peer-reviewed journal, and is wholly unsupported by any evidence whatsoever. It contradicts all evidence from dinosaur anatomy, biomechanics, sedimentology and palaeoenvironments, and does not even qualify as fringe science. It is unsupported and uninformed speculation which Ford could have disproved had he taken just ten minutes to look at the readily available literature representing a century of consensus.

By giving air-time to this speculation, even comparing Ford with Galileo, Radio 4 has unfortunately lent it a credibility that it has not earned, introduced a time-wasting controversy where there is not a controversy, misled the public, and maybe most importantly compromised its own credibility as a trusted source of science reporting. No listener with any knowledge of palaeontology will have been able to take this report seriously; will they believe the next science report you broadcast?

To mitigate this damage, we recommend and request that you broadcast a formal retraction.

  • Dr. Mike Taylor, Department of Earth Sciences, University of Bristol, UK
  • Dr. David Marjanović, Museum für Naturkunde, Berlin, Germany
  • Silvio C. Renesto, Associate Professor of Palaeontology, Department of Theoretical and Applied Sciences, Università degli Studi dell’Insubria, Italy
  • Dr. Grant Hurlburt, Department of Natural History, Royal Ontario Museum, Canada
  • Dr. Michael Balsai, Department of Biology, Temple University, Philadelphia, USA
  • Dr. Bill Sanders, Museum of Paleontology, University of Michigan, USA
  • Dr. Stephen Poropat, Department of Earth Sciences, Uppsala University, Sweden
  • Dr. Oliver Wings, Curator of Vertebrate Palaeontology, Museum für Naturkunde, Berlin, Germany
  • Jon Tennant, Independent Researcher, UK
  • Prof. John R. Hutchinson, Department of Veterinary Basic Sciences, The Royal Veterinary College, UK.
  • Prof. Lorin R. King, Dept. of Science, Math and Physical Education, Western Nebraska Community College
  • Scott Hartman, paleontologist and scientific illustrator, SkeletalDrawing.com
  • Neil Kelley, Department of Geology, University of California at Davis, USA
  • Dr. Matteo Belvedere, Department of Geosciences, University of Padova, Italy
  • Andrew R. C. Milner, Paleontologist and Curator, St. George Dinosaur Discovery Site, Utah, USA
  • Dr. James I. Kirkland, State Paleontologist, Utah Geological Survey, USA
  • Dr. Jerry D. Harris, Director of Paleontology, Dixie State College, Utah, USA
  • Dr. Andrew A. Farke, Curator, Raymond M. Alf Museum of Paleontology, Claremont, California, USA
  • Dr. Daniel Marty, Editor (Palaeontology) of the Swiss Journal of Geosciences
  • Dr. Manabu Sakamoto, School of Earth Sciences, University of Bristol, UK

(My thanks to all who signed.)

To give it the best chance of being seen by the relevant people, I submitted this three times on the BBC’s rather confusing web-site: on the Today feedback page, on the BBC complaints page, and on the Contact Today page.

Today at 2pm, I got the following reply:

Dear Dr Taylor

Reference CAS-1387310-3W6PSD

Thanks for contacting us regarding ‘Today’ broadcast on BBC Radio 4 on 3 April.

I understand that you were unhappy with the inclusion of a report by Tom Feilden on a theory proposed by Professor Brian Ford regarding how dinosaurs’ lived. I note you believe the report gave credibility to this theory, and compared the professor with Galileo.

Your concerns were forwarded to the programme who explained in response that the item in question was a light-hearted feature looking at an outlandish new idea about the dinosaurs and which was clearly signposted as such.

They added that the item even included one of the world’s leading experts on dinosaurs, Paul Barrett, exposing it’s flaws and ridiculing it and that it was very clear where Brian Ford’s article was published since Laboratory News was clearly mentioned.

They also added that the reference to Galileo was simply an aside about the importance of dissent in science, with Brian Ford was unlikely to be put off by the condemnation of the established experts, and not, as you suggest, a comparison between Brian Ford and one of the greatest scientists of all time.

In closing they explained:

“Today does a lot of good, serious science, indeed that same morning we had items on carbon capture and storage and the controversy over the publication of flu research, but that doesn’t mean it all has to be serious and we must be free to include light-hearted items, reported in a more humorous way.”

Nevertheless, we’re guided by the feedback we receive and I can assure you I’ve registered your complaint on our audience log. This is a daily report of audience feedback that’s made available to all BBC staff, including members of the BBC Executive Board, channel controllers and other senior managers.

The audience logs are seen as important documents that can help shape decisions about future programming and content.

Thanks for taking the time to contact us.

Kind Regards

Mark Roberts

BBC Complaints

I guess I don’t need to say that I find this completely unsatisfactory.  Trying to pass the segment off as “a light-hearted feature looking at an outlandish new idea about the dinosaurs and which was clearly signposted as such” just won’t fly: its page on the BBC site is entitled “Aquatic dinosaur theory debated”, and there is nothing about it that signposts it as any less serious than, say, the piece they did with me on Brontomerus, or on sauropod neck posture.

As it happens, my mum called me for a chat a couple of days ago, asking me whether I’d heard “the new theory” on the Today show.  It was pretty painful having to let her down.  She obviously didn’t hear it as “a light-hearted feature”.  It’s going to be harder now for her to accept other science reporting on Today.

The response claims that “the reference to Galileo was simply an aside about the importance of dissent in science […] and not, as you suggest, a comparison between Brian Ford and one of the greatest scientists of all time”.  Well, let’s take a listen and see what exactly was said:

Somehow, I don’t think that [Paul Barrett’s gentle disagreement] is going to be enough to persuade Professor Brian Ford. As another famous scientific dissenter, Galileo, was reported to have to have muttered under his breath when forced to deny that the Earth revolves around the Sun, “Eppur si muove” — “And yet, it moves“.

Yikes.

This is just so disappointing.  It would have taken Today‘s Tom Feilden five, maybe ten minutes of high-school-level research to discover that Ford has no grounding in palaeontology, sedimentology, biomechanics or palaeoenvironments; that his “theory” is as emphatically contradicted by the evidence as geocentricism; and that its publication was in a trade newsletter.  By skipping that basic due diligence, and blindly reporting Ford’s fantasy as serious science, Today has dramatically undermined its own credibility; by refusing to retract or even apologise, they’ve missed a chance to regain some of that lost credibility.

Why does it matter?  Scott Hartman said it best:

We live in a world where huge swaths of people don’t understand basic scientific concepts, and this sort of nonsense just makes it harder to teach. Worse, listeners that were sympathetic to the reporting will become disillusioned when they find out the reality of the situation, possibly making them view all science more cynically (or simply avoiding science altogether).

We deserve better science reporting than this. The BBC and everyone else who carried this story should be ashamed.

Yes.

In among all the open-access discussion and ostrich-herding, we at SV-POW! Towers do still try to get some actual science done.  As we all know all too well, the unit of scientific communication is the published paper, and getting a submission ready involves a lot more than just the research itself.  One of the most important aspects is preparing the illustrations — indeed Matt once told me that he thinks one of the best ways to put a paper together is to start with the illustrations, then write the text around them.

[Illustrations are often referred to as “figures”.  I don’t know how the tradition got started, but since that term also means numbers, I will try to avoid it.  If I tell you “I am working on the figures for my diversity paper”, you don’t know if I am accumulating statistics or preparing illustrations.]

Done well, illustrations can be things of beauty as well as scientifically informative.

Taylor et al. 2011b:fig. 1 -- Sauropod neck gallery

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

There are a few things to be said about preparing good illustrations, so we’re kicking off a short series on the subject.  This is the first.

But the zeroth was published here a couple of years ago.  Since the most important illustrations in many palaeontology papers are those of the specimens, the base you’re working from is your specimen photographs.  So you might want to refresh your memory by reading Tutorial 8: how to photograph big bones before we proceed.

There are various steps in getting from a photo to a finished, publishable figure, and we’ll look at those along the way.  But somewhere along the line, if you’re publishing in a conventional journal such as the Journal of Vertebrate Paleontology, you’re going to flatten your colour images down to greyscale. Postpone that step till the last possible moment.

That should be too obvious to need saying, but I’ve got it wrong myself.  When I was preparing the specimen photographs for the Xenoposeidon paper, destined for Palaeontology, I flattened the images too early in the process, with the result that the greyscale versions of the figures that were included in the paper are the only versions in existence.  The upshot is that if you look at the full-resolution illustrations in the unofficial supplementary information, you’ll see that the version of Figure 3 available there is greyscale, just like the one in the paper.

By the time the three of us did our neck-posture paper in Acta Palaeontologica Polonica, we weren’t quite so dumb.  So although the illustrations in the published paper are all greyscale, the two that are based on specimen photographs, rather than assembled from previously published greyscale components, were prepared in full colour, then flattened as the very last process before submission.  As a result, the full-resolution illustrations in the unofficial supplementary information have figures 1 and 2 in colour:

Taylor et al. (2009: Figure 1). Cape hare Lepus capensis RAM R2 in right lateral view, illustrating maximally extended pose and ONP: skull, cervical vertebrae 1-7 and dorsal vertebrae 1-2. Note the very weak dorsal deflection of the base of the neck in ONP, contrasting with the much stronger deflection illustrated in a live rabbit by Vidal et al. (1986: fig. 4). Scale bar 5 cm.

So we were pretty happy with that.  But by the time we came to submit the Brontomerus description a couple of years later, we’d had a rather obvious (in retrospect) thought: just because we can’t have colour in the printed journal, does that mean we can’t have it in the PDF?  We asked the good people at Acta Pal. Pol., and they agreed that we could submit colour illustrations, they’d use them in the PDF, and then flatten them to greyscale themselves for the printed edition.

Since about fifty times as many people see the PDF as see the printed journal [yes, I just made than number up out of my head], that solution suited us very well.  The outcome was the the PDF has gorgeous figures like this one:

Taylor er al. 2011a: fig. 4 -- Brontomerus caudal vertebra

Taylor et al. (2011a: figure 4). Mid-caudal vertebra of the camarasauromorph sauropod Brontomerus mcintoshi from the Lower Cretaceous Cedar Mountain Formation of Utah, OMNH 61248 in dorsal (A), anterior (B), left lateral (C), posterior (D) and ventral (E) views.

(I’m slightly sorry to be displaying all our own illustrations here, but they do make the point and frankly I like looking at them.  Especially that beautiful caudal vertebra.)

Why am I making such a big deal about colour?  Because colour is information, and as scientists we love information.  When you flatten a colour image to greyscale, you lose information, and that should never be done without regret.  It’s perfectly possible that adjacent regions of a fossil will be a different hue but the same brightness: flatten the image and the two colours look the same, but in the original you can see a distinction.  That’s valuable.

So in this day and age, The Right Thing is:

  • Prepare your figures in colour
  • Submit them in colour
  • If the journal has a printed edition (and charges extra for colour printing, as most do), tell them to flatten to greyscale.

On the other hand, if you’re submitting to an open-access journal — and you should be, if you want to be widely read — there’s a good chance that it’s online-only (as with PLoS ONE and Palaeontologia Electronica), in which case the use of colour is a complete non-issue.  The only reason to prepare monochrome figures then is (as with the Taylor et al. 2011b sauropod-neck bestiary above) when you’re constructing them from pre-existing greyscale images.

References

Taylor, Michael P., Mathew J. Wedel and Darren Naish. 2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54(2):213-230.

Taylor, Michael P., Mathew J. Wedel and Richard L. Cifelli. 2011a. A new sauropod dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA. Acta Palaeontologica Polonica 56(1):75-98. doi: 10.4202/app.2010.0073

Taylor, Michael P., David W. E. Hone, Mathew J. Wedel and Darren Naish. 2011b. The long necks of sauropods did not evolve primarily through sexual selection. Journal of Zoology 285:150-161. doi: 10.1111/j.1469-7998.2011.00824.x

Stegotetrabelodon making tracks at Mleisa, © Mauricio Antón

Sweet new paper out today by Bibi et al. in Biology Letters, on some awesome elephant tracks from the United Arab Emirates. I’ve known this was coming for a while, because the second author on the study, Brian Kraatz, has his office about 30 feet down the hall from mine. And I just ran into the lead author, Faysal Bibi, at the Museum fur Naturkunde in Berlin when I was there in December. I knew Faysal when he was an undergrad at Berkeley, and now he’s Dr. Bibi and doing a postdoc in Berlin–how time flies. Congratulations to Faysal, Brian, and the rest of the team on a really cool discovery.

The study is nothing to do with sauropods, but it has a lot of weird connections to SV-POW! Most importantly, the paper is open access, which is both awesome and timely. The life restoration is by the wicked talented Mauricio Antón, who is best known for his paleomammals work but who also restored Brontomerus for National Geographic last year. And some comparative data used in the paper was supplied by SV-POW! favorite and sometime sci-fi author John Hutchinson.

Finally, the elephants that made the tracks were probably Stegotetrabelodon, and although they might not have been full-on Tolkien-by-way-of-Jackson Amphicoelias-sized war-beasts, they were still big four-tusked proboscideans, so I’m calling them oliphaunts. Bibi et al. didn’t find any evidence that the trackmakers were ridden by Haradrim, but they didn’t find any evidence that they weren’t, so that’s how I’m going to imagine them.

Probably not the Mleisa trackmakers. Dammit.

For more stuff, including the paper, the full-res version of the image at top, more sweet images, author bios, and so on, see the press page. There are also nice writeups at Not Exactly Rocket Science and Laelaps. Go check it out.

Reference

Bibi, F., Kraatz, B., Craig, N., Beech, M., Schuster, M., and Hill, A. 2012. Early evidence for complex social structure in Proboscidea from a late Miocene trackway site in the United Arab Emirates. Biology Letters. doi: 10.1098/rsbl.2011.1185

Best. Conference. Ever.

December 12, 2011

I’m just back from a three-day conference in Bonn, Germany, which I unhesitatingly nominate as the best I’ve ever been to.  To begin with, the subject was a guaranteed winner: sauropod gigantism.  I can hardly overstate how awesome it was to hear 43 talks about or relevant to sauropod gigantism (sixteen on the first day, fifteen on the second and twelve on the third).  For another thing, it was one of those rare occasions where all three SV-POW!sketeers got together — I think the fourth or fifth time ever.  For yet another, I met honorary SV-POW!er Ranger Vanessa Graff and Brontomerus artist Francisco “Paco” Gasco for the first time.  And it’s always good to spend time with people like biomechanics wizard John Hutchinson and occasional SV-POW! guest-blogger Heinrich Mallison.  (Apologies to those I’ve not mentioned by name: lots of good people!)

Left to right: Mike, Darren, Matt, Paco. Note the complete lack of commitment in Paco's MYDD expression. Matt's showing how it should be done. Darren seems to have had something unfortunate happen to his nose, and (in this picture, not in real life) look like a hobgoblin. Nothing personal. Just saying.

The meeting was The 2nd International Workshop on Sauropod Biology and Gigantism: a public meeting of DFG Research Unit 533 “Biology of the Sauropod Dinosaurs”.  That’s a mostly German group, headed by Martin Sander, which has been working for nearly eight years on multiple lines towards understanding the evolution of gigantism.  Along the way, that group has produced 105 publications and counting, including a very nice hardcover volume Biology of the Sauropod Dinosaurs: Understanding the Life of Giants, available for the reasonable price of £40 [amazon.co.uk] or $50 [amazon.com].  (Compare with the price of £95 [amazon.co.uk] or $190 [amazon.com] for the comparably sized Geological Society volume on the history of dinosaur palaeontology.  Hang your head in shame, GeolSoc.)  Maybe most importantly, the group published a big synthesis paper at Biological Reviews that is freely available, and which everyone interested in sauropod palaeobiology should read to understand the current state of the field.  Although I certainly don’t agree with everything that’s been published by the group, overall it’s done excellent work and plenty of it.  So it was a real privilege to be a part of this second public meeting.  (Matt and I were also at the first, three years ago.)

Maybe the greatest thing about this meeting was the involvement of many scientists whose usual work is not on sauropods, but who were able to bring their expertise in other fields and apply it to sauropod-related problems.  For example, Jurgen Hummel on on digestive energetics, Michael Fagan on biomechanical modelling, Tom Schanz on soil mechanism (and implications for interpreting tracks) and Jennifer McElwain on plant growth in simulated palaeoatmospheres.  The word “interdisciplinarary” is bandied around a lot, but this conference really fulfilled that description.  That’s truly helpful: for example, five minutes’ conversation with people who actually understand digestive energetics saved me weeks or months of what would have turned out to be fruitless work on the Nourishing Vomit Of Eucamerotus hypothesis.

Wedel is disappointed to discover that baby sauropods didn't need Nourishing Vomit; but Naish is delighted.

Another huge benefit of working with scientists who have other specialisations is the ability to triangulate on a problem.  For example, in my talk on how little we truly know about sauropod necks, I mentioned that we don’t know whether their intervertebral joints were fibrocartilaginous, like those of mammals and crocs, or synovial, like those of birds.  I had been hoping to get a student working on comparative dissections of birds and crocs in the hope of identifying osteological correlates that might allow us to recognise relevant indications in sauropod bones.  But Martin Sander pointed out that histological analysis of the preserved osseous articular surfaces might allow us to tell directly what kind of joint was used — an approach that would never have occurred to me.

So: scientists who know about things other than sauropods. Recommended.

Unlike most conferences, this one allowed time for discussion after each talk — something that made a huge difference.  The slots allocated were each 30 minutes long, but speakers were asked to use only half of that time.  In practice, many talks ran twenty minutes or so, but nevertheless the kind of discussion that you get in ten minutes is qualitatively different from the rather perfunctory one-quick-question-and-move-on that you get at most meetings.  It was in those intervals that a lot of important ambiguities were clarified, misunderstandings remedied, and ideas explored.  (I’d love to see this become more widespread, but of course I understand the difficulty of fitting all the talks into the programme at a larger conference like SVPCA.  Not to mention SVP.)

Unsurprisingly, highlight talks for me included those by Matt (reviewing the last three years’ developments in pneumaticity, and considering the way forward) and Darren (presenting our no-necks-for-sex work in a way that was both persuasive and funny).

The last slide of Darren's talk; original source unknown

But perhaps the talk I enjoyed most was Vanessa’s on neck support hypotheses (ligament, pneumatic stabilisation, ventral compressing bracing, muscle).  It’s only the second time she’s presented at a conference, and the first time ever in palaeo.  Having workshopped the content of the talk extensively, first with Matt, then with both of us, she then prepared the presentation within an inch of its life and did a fine job of delivering it.

Me commenting on one of Vanessa's slides. Needless to say, my comments were all helpful, constructive, and tactfully delivered.

There is good news for the 6,999,999,940 of you who missed this conference: the sessions were all recorded on video, and will hopefully become available shortly.  And there will be a proceedings volume — exact venue to be announced, but we have some good options.  Matt, Vanessa and I will all contribute to this.  (Darren won’t, of course, since his talk was describing already-published research.)

And more good news for the future: although the funding for DFG Research Unit 533 is coming towards an end — it has about a year left to run — the people who have been running it are keen to hold a 3rd International Workshop, in maybe three years’ time.  It’s not clear yet where the funding will come from, but let’s hope they come up with something!

… and a correction to Taylor et al. (2009)

One point that came up in Kent Stevens’ talk was a factual correction to something we wrote in our 2009 neck-posture paper, and it seems right that we should put it on the record.  We wrote (Taylor et al. 2009:216) that:

Physical manipulation of the mounted Diplodocus skeleton DMNH 1494, by Ken Carpenter, resulted in a mounted posture in which the neck is extended farther vertically and horizontally than is allowed by Stevens and Parrish’s digital model (personal observation).  Since the neck of this mount is a cast of the Diplodocus carnegii holotype CM 84, the very same individual used by Stevens and Parrish (1999), it is evident that the results of such computerised studies are not as objective as they may appear.

The Denver Diplodocus mount

Regarding the provenance of the Denver Diplodocus mount, we were misled by the DMNH online catalogue.  Sadly, it doesn’t seem to be online any more, but this is the information it gave regarding the reconstructed portions:

Majority of specimen exhibited in Prehistoric Journey; skull cast from CM 1161, cervicals cast from CM 84, Left scapula, and L & R humeri, radii, & ulnae all cast from HMNS 175 (Houston Musuem of Natural Science), distal 6 caudals cast from Western Paleontology Laboratory specimen.

Kent has spoken to Ken Carpenter about this mount, and it turns out that while the majority of the neck is indeed a CM 84 cast, the last three or so posterior cervicals are from a different specimen — presumably DMNH 1494 itself — and are somewhat restored in plaster.  Thanks to Kent for clearing this up.

(Regarding the rest of Kent’s talk: I’ll withhold comment until Kent publishes his criticisms.)

Update (the next day)

Thanks for John H. and Heinrich, who both tweeted the conference.  You can (for now, anyway) read their comments, and a few by other people, in the saved messages under #SauroBonn.  But I don’t know how long they last, and I don’t know a good way to save them.  Can anyone help?

 

Posts on Paleoart

November 21, 2011

We’ve had the good fortune to work with some very talented paleoartists on several of our projects, and we occasionally write posts drawing attention to pieces of paleoart that we think are especially cool or noteworthy, or use paleoart as a springboard for talking about paleobiology. As usual for SV-POW!, the tone of the posts ranges from completely serious to deeply silly.

We also have a series of posts reviewing the Apatosaurus maquette from Sideshow Collectibles, with some thoughts on the likely life appearance of sauropods:

Matt’s posts on his technical illustrations:

Want to roll your own? Check out our DIY Dino posts:

Finally, for lack of a better place to put them, here are links to the complete Umbaran Starfighter Saga:

This is the fourth in a series of posts in which I review the Apatosaurus maquette from Sideshow Collectibles. Other posts in the series are:

A long-running theme here at SV-POW! is that the torsos of most sauropods were not just deep and slab-sided, they were unusually deep and slab-sided, more so than in most other tetrapods (see this and this, and for a more pessimistic take, this). This is something that is easy to get wrong; we are used to seeing round mammalian torsos and a lot of toy sauropods have nearly circular cross-sections. A lot of sculptors of collectible dinos do get the torso cross-section right, though, and the folks who made this Apatosaurus are no exception.

Next item: there’s an upward kink at the base of the tail, as there should be. Gilmore was the first to point this out, in his 1932 paper on the mounting of the Smithsonian Diplodocus (that’s plate 6 from that paper above; the skeleton on the bottom is the more correct one). This came up in the comment thread of the first post in this series, and since I haven’t had any deeper thoughts on the issue in the past week, I’m just going to copy and paste what I wrote then:

The upkink at the base of the tail is unavoidable; the sacrum is shaped like an inverted keystone and there’s no way to get the proximal caudals to do anything but angle upward without disarticulating them…. The reverse keystoning of sauropod sacra is weird. And it’s in every sauropod sacrum I can remember seeing with my own eyes, including Brachiosaurus altithorax. And yet the only authors I can think of off the top of my head who have discussed it seriously are Gilmore (1932), Greg Paul (2010, maybe a magazine article or two I haven’t seen), maybe Jim Jensen (1988), and IIRC Salgado et al. (1997). If there are more, please let me know–this is something I’m very curious about.

The back is gently arched, with the highest point about midway between the shoulder and hip joints. Where the highest point in the back falls depends on a host of factors, including the relative lengths of the forelimb and hindlimb bones, the amount of cartilage on the ends of those bones, the position and angle of the scapula on the ribcage, and the intrinsic curvature, if any, of the articulated series of dorsal vertebrae, which were themselves separated by an unknown amount of cartilage. Opinions are all over the map on most of these issues, particularly scapular orientation. As a scientist, I am agnostic on most of these points; I don’t think that they’re beyond being sorted out, but there’s a lot of work in progress right now and I haven’t seen evidence that would definitely convince me one way or another. So in lieu of saying that Apatosaurus must have had this scapular orientation and that dorsal curvature and so on, I’ll just note that the maquette has been a dominant feature in my office for a few weeks now and nothing about the body profile, shoulder position, or limb length has ever struck me as odd or worthy of comment. It looks like Apatosaurus to me. Moving on…

In the last post I talked about the visible bulges in the neck that allow one to count the cervical vertebrae. The maquette also has low bumps along the back that mark the neural spines of the dorsal vertebrae. This doesn’t strike me as unreasonable. Attachment scars for interspinous ligaments run all the way up to the tips of the neural spines in most sauropods, so the entire height of one neural spine was often webbed to the next by a continuous ligamentous sheet, as Janensch (1929: plate 4) drew for Dicraeosaurus in the illustration above (isp.L). I don’t think those ligaments would have prevented the bony tips of the vertebrae from being visible, necessarily, and the epaxial muscles should have been on either side of the interspinous ligaments and in the triangular spaces between the spine tips and the transverse processes.

What might have smoothed out the dorsal body profile are supraspinous ligaments (ssp.L in the plate above). These are present in crocs (Frey 1988: figs. 14, 16, 17) but apparently absent in most birds; at least, I haven’t seen any myself, and the Nomina Anatomica Avium does not mention any (Baumel et al. 1993: 156-157). So on phylogenetic grounds their presence in sauropods is equivocal. That said, the tips of the neural spines in most sauropods are fairly rugose. Does that mean that they were webbed one to the next by interspinous ligaments only, or that they were embedded in supraspinous ligaments as well? I don’t know the answer, and I don’t know if anyone else does, either. The whole issue of intervertebral ligaments in sauropods has received too little attention to date. In the absence of better data, I’ll just say that although I wouldn’t put any money on the proposition that the spines made externally visible bumps in life, neither does it offend me.

There is one fairly nit-picky point that I am honor-bound to mention. Because the dorsal neural spines make bumps, it is possible to count the dorsals, just like the cervicals last time. And this count doesn’t work out quite as well. Apatosaurus should have 10 dorsal vertebrae, but try as I might I can’t see more than 8 bumps along the back, and that’s generously assuming that c14’s spine is pretty well ahead of its rib. Is this pathologically anal to complain about? Quite possibly. On the other hand, by sculpting in those details the artists were basically begging geeks like me to come along and count vertebrae just because we could.

The tail is pretty cool. It is appropriately massive where it leaves the body, and has a visible bulge for the caudofemoralis muscle, which originated in the tail and inserted on the fourth trochanter of the femur. The caudofemoralis is the major femur retractor in lizards and crocs and in most non-avian dinosaurs, and rather than go on about it I’ll just point you to Heinrich Mallison’s awesome post about dinosaur butts. The tail of the maquette also has an awesome whiplash. I could say a ton more about the hypothesized uses of whiplash tails in diplodocids and other sauropods, but I don’t feel like climbing that hill just now. Suffice it to say that the maquette’s whiplash is pretty sweet, and avoids the “scale is too small so I just stuck in a piece of wire” mode of making whiplashes that I’ve seen in other, smaller diplodocid sculpts.

The tail has a row of little spines running down the dorsal midline, which have been de rigeur for life restorations of diplodocids and many other sauropods (ahem) since they were first reported by Czerkas (1993). AFAIK, such spines have only been found preserved in the tail region of diplodocids. That’s not to say that they weren’t present in the neck or the back of diplodocids, or in other sauropod taxa, just that the only good fossil traces of them to date have been from the tails of diplodocids, and maybe just one or two tails. So the presence of little spines in the tail of the maquette and not the back or the neck is perfectly–one might even say slavishly–consistent with the fossil evidence. I’ll discuss the flamboyancy or lack thereof in the maquette in another post, so I’ll say no more about this design choice for now.

The limbs are mostly good. The muscles under the skin look plausible, with one exception. As noted before in this series, Apatosaurus was a freakishly robust critter, and the limbs look appropriately sturdy and well-muscled, except where the thigh meets the hip. There is a visible bulge for the ilium, and the anterior margin of the thigh should converge with the most forward point on the ilium. That’s what the preacetabular blade of the ilium is for: to anchor thigh muscles (discussed here, and also nicely illustrated here). Unless the animal had some kind of wasting disease, there was no bone sticking out beyond the muscle, and so the anterior-most point of the ilium has to be the start of the anterior margin of the thigh.

On the positive side, there’s a little ridge running down from the anterior arm onto the forearm for the biceps tendon, which is a nice touch. The manus shows the short, solid arc of metacarpals typical for diplodocids, and an inward-curving thumb claw. The hind feet have the big laterally-curving claws on the first three digits that one expects.

In a way that is difficult to describe in words, the feet really look they are bearing a lot of weight, and this impression of solidity helps to ground the whole maquette. It doesn’t look like a sauropod-shaped balloon that just happens to be poling itself along with limbs that barely touch the ground–an impression that I have gotten occasionally from some other sculptures with overly skinny limbs and too-small feet. This critter looks big, heavy, and powerful, and those are exactly the adjectives one wants to come to mind when looking at Apatosaurus. (I do wonder if doing a Diplodocus in the same scale would be more difficult. How do you convey ‘multi-ton animal’ and ‘gracile’ at the same time?)

To sum up, in the trunk, tail, and limbs I find much to like and little to criticize. The only noteworthy problems are the insufficient dorsal count and the mismatch between the ilium and anterior thigh profile. On one hand these are puzzling goofs, given the overall attention to detail and the numerous points at which the sculpt is not just good but surprisingly good. On the other hand, I didn’t notice the dorsal thing until I bothered to count, and I didn’t notice the thigh thing until the other day when I was writing the first draft of this post, so both problems went unnoticed for weeks and are probably below the threshold of perception for the vast majority of people. The accuracy of the sculpt is so high that my approach to its problems has not been, “Where do I begin?” but rather, “What is keeping this thing from being perfect?” And the answer is, not very much.

Headless sauropod. NOW it's perfect.

The base is nice. It’s not just a generic slab of earth, it’s a muddy surface marked with the tracks of other dinosaurs, including a couple of theropods. The base sits nice and flat, and the Apatosaurus sits nice and flat on it, with no rocking at either point of contact. Not only do the feet of the Apatosaurus fit neatly into the sculpted footprints, one of the hindfeet has a little metal rod that slots into a socket in one of the hindfoot prints, to keep the maquette firmly on the base. That means that if you want to display the maquette off the base, you’ll have to either cut off the rod or make sure that your alternative surface will accommodate it.


The skull is…less satisfying. It’s a nice enough rendition of an Apatosaurus skull, and if it had come by itself I would have been very happy with it. The trouble is that the maquette is considerably more detailed, so when the skull sits next to the maquette it suffers by comparison. But what else are you going to do with it? Make a separate shrine to Apatosaurus somewhere else?

The difference in sculpt quality between the maquette and base on one hand and the skull on the other is apparent even on casual inspection. My copies are sitting on a bookcase adjacent to my office door. Sometimes people walking down the hall pop their heads in, and so far the most common comments are that the maquette is “awesome” and that the base is “cool”. People have been genuinely impressed that the base is a realistically detailed chunk of the environment and not just a flat slab. The only people who have commented on the skull have said that it seems “lame” compared to the maquette.

The base is included in the basic package with the maquette, in a limited edition of 500, which as of this writing goes for $289.99 (here). The package with the skull accessory is in an edition of 100, and goes for $299.99 (here). So the skull is only $10 more, and although it is not quite as nice as the maquette, I think it’s a steal at the price. Mine is certainly not going anywhere.

So much for the gross anatomy. You probably noticed that I haven’t said anything about how the maquette is posed or textured or colored. Those will all be topics for next time.

References

  • Baumel, J.J., King, A.S., Breazile, J.E., Evans, H.E., and Vanden Berge, J.C. (eds.) 1993. Handbook of Avian Anatomy: Nomina Anatomica Avium, 2nd ed. Publications of the Nuttall Ornithological Club, No. 23. Cambridge, Massachusetts, 779 pp.
  • Czerkas, S.A. 1993. Discovery of dermal spines reveals a new look for sauropod dinosaurs. Geology 20:1068–1070.
  • Frey, E. 1988. Anatomie des Körperstammes von Alligator mississippiensis Daudin.
  • Gilmore, C. W. 1932. On a newly mounted skeleton of Diplodocus in the United States National Museum. Proceedings of the United States National Museum 81:1-21.
  • Janensch, W. 1929. Die Wirbelsäule der Gattung Dicraeosaurus. Palaeontographica Suppl. 7(1), 3(2), 37-133.
  • Jensen, J.A. 1988. A fourth new sauropod dinosaur from the Upper Jurassic of the Colorado Plateau and sauropod bipedalism. Great Basin Naturalist 48(2):121-145.
  • Paul, G.S. 2010. The Princeton Field Guide to Dinosaurs. Princeton University Press, 320 pp.
  • Salgado, L., R.A. Coria, and J.O. Calvo. 1997. Evolution of titanosaurid sauropods. I: Phylogenetic analysis based on the postcranial evidence. Ameghiniana 34:3-32.