This was an interesting exercise. It was my first time generating a poster to be delivered at a conference since 2006. Scientific communication has evolved a lot in the intervening decade, which spans a full half of my research career to date. So I had a chance to take the principles that I say that I admire and try to put them into practice.

It helped that I wasn’t working alone. Jann and Brian both provided strong, simple images to help tell the story, and Mike and I were batting ideas back and forth, deciding on what we could safely leave out of our posters. Abstracts were the first to go, literature cited and acknowledgments were next. We both had the ambition of cutting the text down to just figure captions. Mike nailed that goal, but my poster ended up being slightly more narrative. I’m cool with that – it’s hardly text-heavy, especially compared with most of my efforts from back when. Check out the text-zilla I presented at SVP back in 2006, which is available on FigShare here. I am happier to see, looking back, that I’d done an almost purely image-and-caption poster, with no abstract and no lit cited, as early as 1999, with Kent Sanders as coauthor and primary art-generator – that one is also on FigShare.

I took 8.5×11 color printouts of both my poster and Mike’s, and we ended up passing out most of them to people as we had conversations about our work. That turned out to be extremely useful – I had a 30-minute conversation about my poster at a coffee break the day before the posters even went up, precisely because I had a copy of it to hand to someone else. Like Mike, I found that presenting a poster resulted in more and better conversations than giving a talk. And it was the most personally relaxing SVPCA I’ve ever been to, because I wasn’t staying up late every night finishing or practicing my talk.

I have a lot of stuff to say about the conference, the field trip, the citability of abstracts and posters (TL;DR: I’m for it), and so on, but unfortunately no time right now. I’m just popping in to get this posted while it’s still fresh. Like Mike’s poster, this one is now published alongside my team’s abstract on PeerJ PrePrints.

I will hopefully have much more to say about the content in the future. This is a project that Jann, Brian, and I first dreamed up over a decade ago, when we were grad students at Berkeley. Mike provided the impetus for us to get it moving again, and kindly stepped aside when I basically hijacked his related but somewhat different take on ontogeny and serial homology. When my fall teaching is over, I’m hoping that the four of us can take all of this, along with additional examples found by Mike that didn’t make it into this presentation, and shape it into a manuscript. I’ll keep you posted on that. In the meantime, the comment field is open. For some related, previously-published posts, see this one for the baby sauropod verts, this one for CM 555, and this one for Plateosaurus.

Flying over Baffin Island on the way home.

And finally, since I didn’t put them into the poster itself, below are the full bibliographic references. Although we didn’t mention it in the poster, the shell apex theory for inferring the larval habits of snails was first articulated by G. Thorson in 1950, which is referenced in full here.

Literature Cited

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Plateosaurus is comical

September 5, 2013

Back in 2008, Matt and I were at the Museum Für Naturkunde Berlin. We spent some time down in the collections, where we were particularly pleased to see the much-admir’d C8 of Giraffatitan‘s paralectotype, MB.R.2181 (previously known as HMN SII).

While we were down there, we found a C8 from Plateosaurus, too, so we put that next to the Giraffatitan vertebra and shot them together:

DSCN5591-giraffatitan-vs-plateosaurus

I’m just sayin’, is all.

Note: after having written this post, I now see that I wrote an essentially identical one, with an essentially identical image, earlier this year. My memory is definitely going. Oh well: since I’ve written this, I may as well post it anyway.

Plateosaurus is pathetic

January 16, 2013

DSCN5593-giraffatitan-vs-plateosaurus

This photograph is of what I consider the closest thing to the Platonic Ideal sauropod vertebra: it’s the eighth cervical of our old friend the Giraffatitan brancai paralectotype MB.R.2181. (previously known as “Brachiosaurusbrancai HM S II — yes, it’s changed genus and specimen number, both recently, but independently.)

And if you look very carefully, down at the bottom, you can see the same vertebra, C8, of the prosauropod Plateosaurus. Pfft.

This photo was taken down in the basement of the Museum für Naturkunde Berlin, on the same 2008 trip where Matt took the “Mike in Love” photo from two days ago. For anyone who didn’t recognise the specific vertebra I was in love with in that picture, shame on you! It is of course our old friend the ?8th dorsal vertebra of the same specimen, which we’ve discussed in detail here on account of its unique spinoparapophyseal laminae, its unexpectedly missing infradiapophyseal lamina and its bizarre perforate anterior centroparapophyseal laminae.

We’re off to Oxford next week for SVPCA, so things may be quiet around here for a few days. Catch you on the flip side.

Plateosaurus trossingensis AMNH 6810 sacrum and pelvis in left dorsolateral view

We’ve shown a lot of sauropod sacra around here lately (for example here, here, and here), so here’s a little look back down the tree.

You haven’t heard from me much lately because I’ve been busy teaching anatomy. Still, I get to help people dissect for a living, so I can’t complain.

Further bulletins as events warrant.

Plateosaurus engelhardti (originally P. trossingensis) SMNS 13200 cervical vertebrae 3-8 in left lateral view. C8 is roughly 15 cm long.

In the recent post on serial variation in sauropod cervicals, I wrote:

Even in ‘adult’ sauropods like the big mounted Apatosaurus and Diplodocus skeletons, the anterior cervicals are less complex than the posterior ones. Compared to posterior cervicals, anterior cervicals tend to have simpler pneumatic fossae and foramina, fewer laminae, and unsplit rather than bifid spines. In all of these things the anterior cervicals are similar to those of juveniles of the same taxa, and to those of adults of more basal taxa. This is also true in prosauropods–in Plateosaurus, the full complement of vertebral laminae is not present until about halfway down the neck.

I was working from memory there and actually understated things a bit. Plateosaurus presacral vertebrae don’t have well-developed spinal laminae, but they do eventually get the four major diapophyseal laminae–the anterior centrodiapophyseal lamina (ACDL), posterior centrodiapophyseal lamina (PCDL), prezygodiapophyseal lamina (PRDL), and postzygodiapophyseal lamina (PODL–please see the lamina tutorial if you need a refresher on these and the other 15 commonly identified laminae). But they aren’t all present halfway down the neck–the ACDL doesn’t really show up until the cervicodorsal transition. The other three kick in sequentially down the neck, as shown in the above image. I think that’s pretty cool, that you get different character states expressed at different points along the neck, in one individual organism, at one time. And possibly also at different times–in sauropods, the anterior cervicals tend to look more ‘juvenile’ or ‘primitive’, even in adult animals, so all of the cervicals go through a juvenile stage, but not all of them grow out of it. I don’t know if there’s a word for that–some kind of serial heterochronotopomorphy or the like–but hopefully someone will enlighten me.

I took the original photo in the collections at the Staatliches Museum für Naturkunde Stuttgart in the spring of 2004. Markus Moser and Rainer Schoch were wonderful hosts during my visit. Mike did all the work of turning the raw photo into a figure, so thanks to him for getting this off my hard drive and out into the world.

UPDATE April 16, 2012: The paper is officially published now. I’ve updated the citation and link below accordingly.

More new goodies:

Yates, A.M., Wedel, M.J., and Bonnan, M.F. 2012. The early evolution of postcranial skeletal pneumaticity in sauropodomorph dinosaurs. Acta Palaeontologica Polonica 57(1):85-100. doi: http://dx.doi.org/10.4202/app.2010.0075

This is only kinda sorta published. The accepted manuscript is now posted on the APP website, and it has a DOI, but it’s not formatted or available in print yet. But after discussing it amongst ourselves, we authors agreed that (1) the paper is globally available and it’s silly to pretend otherwise, (2) there are no nomenclatural ramifications of that fact, and (3) we’re tired of not being able to talk about this stuff. So we’re gonna, starting…now.

A brief tale of Serendipity in Science (TM):

Back in 2004 I was in my third year of grad school at Berkeley. My fellow grad student, Brian Kraatz, gave me a heads up about the 19th International Congress of Zoology coming up in Beijing. Attendees could submit 500-word abstracts or 2000-word short papers. I didn’t plan on doing either one, until the night before they were due, when I changed my mind and wrote almost all of what would become this paper in a single six-hour session (don’t be too impressed; I’ve been trying to replicate that feat for seven years with no success).

That summer, I met up with Brian in Beijing a week before the congress, and we spent the extra time working in the collections of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP). Paul Barrett was there, working on prosauropods, and he and I had some long and fascinating conversations. We also gave our talks in the same session at the congress. Paul must have decided I was not a complete moron because he invited me to give a talk in the basal sauropodomorph symposium at SVP in 2005.

A brief aside: many of the animals I grew up calling prosauropods ended up outside of the monophyletic Prosauropoda that is anchored on Plateosaurus. Some are now basal sauropods, some are closer to sauropods than to Plateosaurus but outside of Sauropoda, and some are outside of Prosauropoda + Sauropoda. The phylogenetically correct term encompassing all of the nonsauropods is  ‘basal sauropodomorphs’, and it means roughly what ‘prosauropods’ did until a decade or so ago. I often slip into informally using ‘prosauropods’, but I try to remember to put the term in quotes so as not to mislead anyone.

I had been to England in 2004 and 2005 and seen the putatively pneumatic vertebrae of Erythrosuchus and what was then known as Thecodontosaurus caducus (and is currently trading under the name Pantydraco caducus for reasons that it would be otiose, for the moment, to rehearse)–and, not incidentally, had finally met Mike in person, although we’d been corresponding since 2000. I’d also been to Stuttgart primarily to see the appendicular material of Janenschia and ended up spending some quality time with Plateosaurus. (Since the theme here is serendipity, note that the Janenschia work–my raison d’etre for going to Germany–died on the table, whereas I’ve now been an author on three ‘prosauropod’ papers and have more in the works. Weird!)

Anyway, with all of that accidental experience with ‘prosauropods’ and other interesting critters like Erythrosuchus, I found that I actually had something to say in 2005 SVP symposium. I titled my talk, ‘What pneumaticity tells us about “prosauropods”, and vice versa’, and it turned into the 2007 paper of the same title.

None of this would have happened if Brian hadn’t hounded me about going to Beijing, and if I hadn’t ended up talking so much with Paul on that trip, and if I hadn’t finished up with Janenschia on my first day in Stuttgart and spent the rest of the week playing with Plateosaurus. And so on. Science is unpredictable, especially for scientists.

When I sent around the PDF of the paper to friends and colleagues, I included this quip: “Were prosauropods pneumatic? The fossils don’t say. Somehow I stretched that out to 16 pages.” Mike claims that because of this quip he’s never been able to take that paper seriously. But it is my favorite among my solo efforts. It includes loads of stuff on the origins of air sacs and pneumaticity that I wasn’t able to get into my earlier papers, either because it wasn’t directly relevant or because some reviewer forced me to excise it.

BUT.

Almost immediately after the paper came out, Adam Yates and Matt Bonnan went and found roughly a zillion pneumatic ‘prosauropods’, which was a bit embarrassing since I’d just concluded that the evidence for ‘prosauropod’ pneumaticity was thin to nonexistent. So it is a damn good thing for me that I was already on friendly terms with both of them, because instead of taking the opportunity to smack me down, they invited me on board. Which led to Adam’s talk at SVP in Bristol in 2009, and to the new paper.

And actually, the depth of my incorrectness was even greater than I had thought. I reckon that literally millions of people have seen the mounted Plateosaurus skeleton in the AMNH, and any of them who have looked closely have seen this:

(Click for full size, unlabeled version.)

You see the problem here, I’m sure: the semi-big, semi-obvious fossa divided by an accessory lamina, not consistent with a muscle attachment point or fat pad or cartilage or infection, but very consistent in both form and location with the pneumatic fossae of other, more derived sauropodomorphs. On the lateral face of the vertebra, probably seen by millions, obvious to anyone who cares to look. A pneumatic prosauropod, in other words, right out in public for decades and decades (this time I don’t have to use the scare quotes because Plateosaurus actually IS a prosauropod sensu stricto). I didn’t even notice the first time I visited the AMNH back in 2006. I took the above photos, which are the basis for Figure 4 in the paper, in 2009.

So: ‘prosauropods’ were pneumatic. Some of them. A little bit. If you’d like to know more, please read the paper–it’s free.

Finally, a big thank-you to Adam and Matt for inviting me to be part of this. I think it’s pretty cool stuff, and I’m sure I’ll have more to say about it in the future. They might too–you should be reading their blogs, Dracovenator and Jurassic Journeys, anyway.

We’re still not done with Brontomerus, by the way. If nothing else, there’s the long-overdue post on how sauropod ilia change (or rather fail to change) through ontogeny. But that’s something we’ll have to get back to next week. Stay tuned.