Peter Falkingham and Nick Gardner independently put me onto Sketchfab: a website that provides a way to view and navigate 3D models without needing to download any software beyond the browser that you’re already running.

So get yourself over to the live Xenoposeidon model! Verify for yourself that the laminae are as I described them, that the posterior margin of the neural arch really does grade into the posterior articular surface of the centum, etc. Really, this is worth ten times whatever set of illustrations I might have provided.

Truly, we are living in the future!

 

Advertisements

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]

 

There’s just time before midnight strikes to wish Xenoposeidon a very happy tenth birthday. It came along just a month and a half after SV-POW! itself — in fact, I can’t even remember now, a decade on, whether part of the reason we started SV-POW! in the first place was so we’d have somewhere to talk about it when the paper (Taylor and Naish 2007) came out.

Taylor 2017: Figure 4. NHMUK R2095, the holotype and only vertebra of Xenoposeidon proneneukos, in left lateral view, interpreted as a rebbachisaurid. This interpretation is modelled primarily on MNHN MRS 1958, a posterior dorsal vertebra from the holotype specimen of Rebbachisaurus garasbae. The CPOL passes through a sheetlike PCDL, as in Rebbachisaurus; but the lateral CPRL forms a cross-shaped junction with the ACPL, each of these laminae equally interrupting the trajectory of the other. Abbreviations as used in the text. Scale bar = 200 mm.

For the last few days, I have been working away like a trojan, trying to ready a new manuscript for launching on this day. I’ve taken two days off from my day-job to get it done before this arbitrary deadline, and here I am writing about it with just 15 minutes to go!

The title of this new manuscript (Taylor 2017) is “Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur”, and it explains in detail the argument that I made informally sixteen months ago when I first saw the rotating video of the Rebbachisaurus garasbae that Jeff Wilson and co put out with their then-new redescription of that species. I got it submitted (to PeerJ, natch) a bit more than an hour ago, and at the same time I clicked the “Make this available as a preprint” button. So as I write this, I am periodically checking back in the other window to see whether it’s made it through the basic editorial checks yet.

The thing is, I really love Xenoposeidon. I admit that a surprising number of people (my wife, Matt, his wife, Heinrich Mallison, his wife) seem to think it looks like a turd. But I honestly think it’s the most beautiful single bone I’ve ever seen. It’s a privilege to work on it.

Taylor 2017: Figure 5. NHMUK R2095, the holotype and only vertebra of Xenoposeidon proneneukos, in left anteroventrolateral view, highlighting the three sets of laminae related to the prezygapophyses. The trajectories of the medial CPRLs (which emerge from the neural arch pedicels) and the lateral CPRLs (which intersect with the APCLs) indicate the approximate position of the prezygapophyses. The additional arched laminae form the margins of the large, teardrop-shaped CPRF, but meet at a position some way below and posterior to the presumed location of the prezygapophyseal facets. Breakage of both medial CPRLs and the left ACPL and PCDL is indicated by cross-hatching. Note that, from this perspective, the lateral CPRL appears to turn a corner where it intersects with the ACPL, such that the posteroventral portion of the lateral CPRL appears contiguous with the dorsal portion of the ACPL. This is an illusion brought about by the eminence at the point of intersection. As always, this is much easier to see in three dimensions. Abbreviations as used in the text.

Anyway, I’ll link to the preprint as soon as it’s up. In the mean time, I’m just going to bask in the beauty that is Xenoposeidon.

Immediate update

Four minutes after posting this, and just three minutes before midnight, I got the notification from PeerJ that the preprint is up! So you are welcome to leave comments about the science on that page if you wish: I will take them into account when I revise the manuscript in light of the formal peer-reviews that will be coming along in due time.

References

 

Out today: a new Turiasaurian sauropod, Mierasaurus bobyoungi, from the Early Cretaceous Cedar Mountain formation in Utah. This comes to us courtesy of a nice paper by Royo Torres et al. (2017),

Royo-Torres et al. 2017, fig. 3. The postcranial skeleton (UMNH.VP.26004) of Mierasaurus bobyoungi gen. nov, sp. nov. with the following elements: (a) middle cervical vertebra (DBGI 69 h) in right lateral view; (b) middle cervical vertebra (DBGI 69G1) in right lateral view; (c) anterior cervical vertebra (DBGI 165) in right lateral view; (d) anterior cervical vertebra (DBGI 69G2) in right lateral view; (e) atlas (DBGI 5I) in anterior view; (f) atlas (DBGI 5I) in right lateral view; (g) posterior cervical vertebra (DBGI 95) in right lateral view; (h) posterior cervical vertebra (DBGI 19 A) in right lateral view; (i) posterior cervical vertebra (DBGI 19 A) in ventral view; (j) middle cervical vertebra (DBGI 38) in right lateral view; (k) middle cervical vertebra (DBGI 38) in dorsal view; (l) middle cervical vertebra in posterior view; (m) middle cervical vertebra (DBGI 38) in left lateral view; (n) right anterior cervical rib (DBGI 5D) in medial view; (o) right anterior cervical rib (DBGI 28 A) in medial view; (p) right anterior-middle cervical rib (DBGI 95 C) in medial view; (q) right middle cervical rib (DBGI 45 F) in dorsal view; (r) right middle cervical rib (DBGI 95 A) in dorsal view; (s) left anterior cervical rib (DBGI 95B) in lateral view; (t) left middle cervical rib (DBGI 95 H) in lateral view; (u) left middle cervical rib (DBGI 95D) in dorsal view; (v) right posterior cervical rib (DBGI 10) in dorsal view. A plus sign (+) indicates a diagnostic character for Mierasaurus bobyoungi gen. et sp. nov. An asterisk (*) indicates an autapomorphy of Mierasaurus bobyoungi gen. et sp. nov. (© Fundación Conjunto Paleontológico de Teruel-Dinópolis) in Adobe Illustrator CS5 (www.adobe.com/es/products/illustrator.html).

[Because this paper is in Nature’s Scientific Reports, it inexplicably has a big chunk of manuscript chopped out of the middle, supplied separately, not formatted properly, and for all we know not peer-reviewed. This includes such minor details as the specimen numbers of the elements that make up the holotype, and the measurements. Note to self: rant about how objectively inferior Scientific Reports is to PeerJ and PLOS ONE some time.]

Anyway, this is a nice specimen represented by lots of decent material, including plenty of presacral vertebrae, which is great.

But here’s where it gets weird. Until now, Turiasauria has been an exclusively European clade. Just like Diplodocidae used to be an exclusively North American clade until Tornieria turned up, and Dicraeosauridae used to be an exclusively Gondwanan clade until Suuwassea turned out to be a dicraeosaur, and so on.

I mentioned this in an email to Matt. His initial take was:

There is a semi-tongue-in-cheek biogeography “law” that states “Everything is everywhere, and the environment selects”.

It is kinda blowing my mind that so many taxa were shared between North America, Europe, and Africa in the Late Jurassic and yet we don’t see any turiasaurs in North America until the Cretaceous. I wonder if they are there in the Morrison and just not recognized — either some of the undescribed or undiscovered northern-Morrison weirdness, or currently lumped in with Camarasaurus.

I responded “That’s one read. Another is that we’re seeing convergence on similar eco-niches within widely different clades, and our analyses are not figuring this out.”

What I mean is this: what if our “Brachiosauridae” clade is really just a collection of not-closely-related taxa in the tall-shouldered very-high-browser ecological niche? And what if our “Dicraeosauridae” clade is just a collection of short-necked grazers, with independent evolutionary origins, but all converging on morphology that suits the same lifestyle?

And that is the thought that is currently freaking me out.

Royo-Torres et al. 2107, fig. 4. The postcranial skeleton (UMNH.VP.26004) of Mierasaurus bobyoungi gen. nov, sp. nov. with the following elements: (a) anterior dorsal vertebra (DBGI 54 A) in posterior view; (b) anterior dorsal vertebra (DBGI 54 A) in anteroventral view; (c) neural arch of a middle dorsal vertebra (DBGI 37) in right anterolateral view; (d) posterior neural arch of a dorsal vertebra (DBGI 19 A) in posterior view; (e) anterior dorsal vertebra (DBGI 16) in right lateral view; (f) anterior dorsal vertebra (DBGI 16) in posterior view; (g) posterior dorsal vertebra (DBGI 16) in anterior view; (h,i) posterior dorsal vertebra (DBGI 100NA 1) in anterior view; (j,k) posterior dorsal vertebra (DBGI 100NA 1) in posterior view; (l) posterior dorsal vertebra (DBGI 100NA 1) in left lateral view; (m) middle dorsal vertebra (DBGI 11) in anterior view; (n) centrum of a posterior dorsal vertebra (DBGI 24B) in ventral view; (o) centrum of a posterior dorsal vertebra (DBGI 24B) in anterior view; (p) centrum of a posterior dorsal vertebra (DBGI 192) in ventral view; (q) anterior-middle caudal vertebra (DBGI 23B) in anterior view; (r) anterior-middle caudal vertebra (DBGI 23B) in right lateral view; (s) posterior neural arch of a posterior caudal vertebra (DBGI 48) in left lateral view; (t) posterior caudal vertebra (DBGI 21) in anterior view; (u) posterior caudal vertebra (DBGI 21) in right lateral view; (v) distal caudal vertebra (DBI 37-34-529) in right lateral view; (W) anterior caudal vertebra (DBGI 192) in posterior view. For abbreviations see supplementary information. (i), (k) and (l) were drafted by R.R.T. (© Fundación Conjunto Paleontológico de Teruel-Dinópolis) in Adobe Illustrator CS5 (www.adobe.com/es/products/illustrator.html).

When I mentioned this possibility to Matt, he shared my existential terror:

What haunts me is this: we know from mammals and extant reptiles that morphological analyses suck. Laurasian moles, African moles, and Australian moles all look the same, despite evolving from very different ancestors. Ditto wolves and thylacines, horses and litopterns, etc.

Matt reminded of a paper we’ve talked about before (Losos et al. 1998), showing that this is exactly what happens with Caribbean anole lizards. Each island has forms that live on the ground, on the trunks of trees, and on branches. Phylogenetic analyses based on morphology put all the ground-livers together, ditto for trunk-climbers, ditto for branch-climbers. But molecular analyses show that each island was colonized once and the ground, trunk, and branch forms evolved separately for each island.

What if “turiasaur”, “brachiosaur”, and “titanosaur” are the sauropod equivalents? For “Caribbean island” read “continent”; for “lizard species”, read “sauropod clade”.

Will we ever know?

Matt is hopeful that we will. He’s confident that in time, we’ll get molecular analyses of dinosaur relationships — that it’s just a matter of time and cleverness. When that happens, things could be upended bigtime.

References

 

More thoughts on SVPCA 2017

October 13, 2017

This morning, I and the other 1456 attendees of SVPCA 2017 received a useful document, SVPCA report_for attendees, which collects and analyses delegates’ feedback on the meeting. It prompted me to mention a few more thoughts of my own.

First, I didn’t like the shortening of the meeting, from the usual three or even four days to two and a half (or just two if you ignore the macroevolution symposium). But it’s apparent from the gathered feedback that nearly everyone disagrees with me on this.

My position may be an artifact of my idiosyncratic status on the edge of the field: SVPCA is pretty much my only physical (non-blog) contact with the vertebrate palaeontology community, so by the time I’ve taken a week off work for it, the more of that time I can use for it, the better. By contrast, people who spend most of their work-hours with other palaeontologists don’t have that incentive, and see a longer meeting as a financial burden. I’m guessing that if the survey had specifically asked for opinions on meeting length and then compared those opinions with people’s career stage, they’d find a strong correlation between amateur and other unusual statuses, and preferring a longer meeting.

Sadly (for me), it seems pretty clear how this one is going to go: the meeting is attended overwhelmingly by professionals of various career stages. Since the majority of those prefer the shorter meeting, I imagine Birmingham’s abridged programme will become the new normal.

Second thing: a lot of people complained that the posters were only up for the dedicated two-hour session, and quite a few didn’t like having a dedicated poster session at all. Once more, I find myself in a minority here. As someone presenting a poster, I very much appreciated having time dedicated to it. And I also liked that it was restricted to a specific slot, so I didn’t feel I had to spend the whole meeting babysitting the poster. Wine was provided for this session, which made it feel like a friendly, bustling session with plenty of science going on, and time to go and physically fetch the people who I specifically wanted to discuss my poster with.

So I would definitely support a dedicated two-hour poster session with wine at future meetings; though I wouldn’t object if the posters remained up in the background for the next day, if that was logistically easy. (It wasn’t in Birmingham.)

The third thing, which I forgot to mention on my feedback form, is that lightning talks need to be all together in a single session. These talks didn’t really work at Birmingham. By tagging two or three of them on the end of a regular session, they simply came across as a lesser versions of regular talks — tail-enders with no particular merit of their own.

But I do think lightning talks can work well: I’ve been in conferences (admittedly in computer science and library science rather than palaeo) where the lightning-talk sessions have been the best in the conference. The key is keeping all of them together in a single, dedicated session, and really keeping the pace up: whizzing through each talk within a strictly enforced five-minute time limit, and leaping from subject to subject. It can be exhilarating.

(There were specific reasons why it couldn’t be done this was at this year’s meeting — paucity of lightning-talk submissions, people’s difficult schedules and unexpected withdrawals all meant that the original plan couldn’t be adhered to. But I would hate to see lightning talks dropped from the conference because of their underwhelming impact this time around.)

The fourth thing is that I was not wholly convinced by the symposium. Given the scarcity of talk slots, their limited length, and the carefully blinded abstract review process, it seems inimical to invite a special anointed class of speakers who get twice as long and don’t have to go through review.

I might have been convinced despite this, had the quality of the talks been uniformly higher. But as one respondent to the survey wrote: “I was alarmed and disappointed to hear one presenter say that they had put their talk together the night before, and it showed”. It really did. Surely if being invited to give a double-length talk is anything, it’s an honour. People in receipt of that honour should either do their job to a level that merits it; or, if they don’t have time, politely decline and let someone else have the slot.

Finally, and least important, the annual dinner. This was a curry, with a good selection and far more food than we needed. But the report says “there have been a few comments […] that more people might attend if the food was more of a meat-and-two-veg type affair, and that some people would like to see a more formal, or more ‘special’ dinner”. For whatever it’s worth, I threw my hat in partly because it was a curry. In my experience, attempts at catering “special” dinners for large groups tend to produce mediocre food tarted up, which is why my group tends to skip the dinner.

But I’m glad I went this year. I liked the sense of being part of an ongoing community, of seeing the handover to next year’s host (Rob Sansom), hearing who the winners of the prizes were, and so on.

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

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

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

February 1, 2008: Your neck is pathetic

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

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

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

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

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

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

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

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

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

January 16, 2013: Plateosaurus is pathetic

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

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

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

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

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

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

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

August 15, 2017: “Biconcavoposeidon”

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

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

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

 

Amazingly (to me, anyway), SV-POW! is ten years old today. It was on 1st October 2007 that we published Hello world!, our first post, featuring a picture of what may still be our favourite single sauropod vertebra: the ?8th cervical of the Giraffatitan brancai paralectotype MB.R.2181. Of course, back then, we thought it was the type (it’s not), it was thought to belong to Brachiosaurus brancai (mea culpa), and the specimen number was HMN SII. A lot has changed in ten years, but the vertebra is still heart-breakingly beautiful.

Some other things have changed in those ten years, of course. Three of us started the blog, but one (Darren) has become a sleeping partner due to the enormous success of his other blog, Tetrapod Zoology. We began intending to be a picture blog, but we’ve ended up as a 50-50 blend of sauropod palaeontology and open-access advocacy. Along the way, I (Mike) got my Ph.D, and Matt moved from UC Merced to Western University of Health Sciences, where both he and his wife Vicki now have tenure. Darren meanwhile has carved out a unique niche for himself as a writer and consultant, and has his own cconference.

We never thought this blog would run for so long — I seem to remember the original plan was to make 52 weekly posts, then call it a day after one year. In fact, over the last ten years, we’ve posted 1160 articles, for an average of one every 3.15 days: more than twice as often as the weekly schedule that the blog title suggests. But not all those posts have included sauropod vertebrae — so, guessing that about half of them have, we’re more or less on target.

In the mean time, you have written 16820 comments, for a pretty healthy average of 14.5 per post. One of the things I’m proudest about regarding this blog is that we’ve only once had to shut a thread down because it became unproductive; and I think on only two other occasions have we had to issue a public warning. We have a fantastic community of commenters here, and my deeply felt gratitude goes out to you all.

Our most-read post at the time of writing is Every attempt to manage academia makes it worse (with 214,438 views), followed by Elsevier is taking down papers from Academia.edu (62,695), SV-POW! showdown: sauropods vs whales (35,944) and How big was Amphicoelias fragillimus? I mean, really? (35,531). These lead a list of 35 posts that have each garnered more than 10,000 views, contributing to an overall total of 3,573,821 views (which gives us an average of 3,080 views per post). We are alternately delighted, baffled and impressed that the world has shown such interest.

We have one or two things planned for this week of the 10th anniversary, but for this post I just want to leave it like this: THANK YOU ALL for reading, commenting and engaging with this blog. Thank you, palaeontologists for putting up with the open-access posts, and thank you scholarly communication specialists for putting up with the sauropods. We hope it’s been interesting, entertaining and sometimes thought-provoking; and we hope we can continue in the same vein. (We certainly have no plans to stop any time soon.)

We love you guys.