Regular readers will remember that we followed up our 1VPC talk about what it means for a vertebra to be horizontal by writing it up as a paper, and doing it in the open. That manuscripts is now complete, and published as a preprint (Taylor and Wedel 2019).

Taylor and Wedel (2018: Figure 5). Haplocanthosaurus sp. MWC 8028, caudal vertebra ?3, in cross section, showing medial aspect of left side, cranial to the right, in three orientations. A. In “articular surfaces vertical” orientation (method 2 of this paper). The green line joins the dorsal and ventral margins of the caudal articular surface, and is oriented vertically; the red line joins the dorsal and ventral margins of the cranial articular surface, and is nearly but not exactly vertical, instead inclining slightly forwards. B. In “neural canal horizontal” orientation (method 3 of this paper). The green line joins the cranial and caudal margins of the floor of the neural canal, and is oriented horizontally; the red line joins the cranial and caudal margins of the roof of the neural canal, and is close to horizontal but inclined upwards. C. In “similarity in articulation” orientation (method 4 of this paper). Two copies of the same vertebra, held in the same orientation, are articulated optimally, then the group is rotated until the two are level. The green line connects the uppermost point of the prezygapophyseal rami of the two copies, and is horizontal; but a horizontal line could join the two copies of any point. It happens that for this vertebra methods 3 and 4 (parts B and C of this illustration) give very similar results, but this is accidental.

The preprint has all the illustrations and their captions at the back of the PDF. If you prefer to have them inline in the text, where they’re referenced — and who wouldn’t? — you can download a better version of the manuscript from the GitHub archive.

By the way, you may have noticed that what started our written in Markdown has mutated into an MS-Word document. Why? Well, because journals won’t accept submissions in Markdown. It eas a tedious and error-prone job to convert the Markdown into MS-Word, and not one I am keen to repeat. For this reason, I think I am unlikely to use Markdown again for papers.

References

  • Taylor, Michael P., and Mathew J. Wedel. 2019. What do we mean by the directions “cranial” and “caudal” on a vertebra? PeerJ PrePrints 7:e27437v2. doi:10.7287/peerj.preprints.27437v2

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This awesome photo was taken in the SVPCA 2019 exhibit area by Dean Lomax (L). On the right, Jessie Atterholt, me, and Mike are checking out some Isle of Wight rebbachisaurid vertebrae prepped by Mick Green, who is juuuust visible behind Dean. Jessie’s holding a biggish (as rebbachisaurids go) dorsal or caudal centrum and partial arch, me a lovely little cervical, and Mike an astonishingly delicate and beautiful dorsal. You can see behind us more tables full of awesome fossils, and there were more still across the way, behind Dean and Mick. I was going to throw this photo into the last post to illustrate the exhibit area, but by the time the caption had hit three lines long, I realized it needed a post of its own.

Photo courtesy of Dean, and used with permission. Mark your calendars: on Sunday, Oct. 13, Dean will be speaking at TEDx Doncaster, with a talk titled, “My unorthodox path to success: how my passion for the past shaped my future”. You can follow the rest of Dean’s gradual conquest of the paleosphere through his website, http://www.deanrlomax.co.uk/.

As usual I came back from SVPCA to a mountain of un-dealt-with day-job work, which is why it’s taken me so long to get this post done and up. I wanted to get it posted as quickly as I could decently arrange, because I had a fantastic time at this year’s meeting and I wanted to document a few reasons why, both to thank this year’s hosts and to perhaps inspire the organizers of future meetings.

A shot from the back of the banquet-hall-turned-lecture-theater during Mike’s talk.

1. Space

This year’s presentation space was unlike any I can remember from previous SVPCAs. Instead of being in a lecture hall, talks were held in a big ballroom, and attendees sat in chairs at big circular banquet tables. This had a LOT of positive effects: no edging along long rows of seats to get in or out between talks, easy discussion around and between the tables at the breaks, the opportunity for a group of people to sit together as a group (vs a line or same-facing block), plenty of space to set notebooks, laptops, papers, pens, drinks, etc. I realize that meeting space is probably one of the things that conference organizers have the least control over, but at least from what I saw this year I’d say the ballroom model works even better than the lecture hall model, so that’s a possible consideration for the future.

2. Time

Owing to the smaller-than-normal number of abstract submissions — possibly a function of the meeting being on an island rather than the, uh, somewhat larger island of Great Britain — everyone who asked for a talk got one, and the talk slots were long enough for full 15-minute talks and 5 minutes for questions. So the meeting seemed decompressed. No-one really rushed through their talks (although Mike did speak very quickly), and there was usually plenty of time for questions, and the all-important coffee top-up or between-breaks bio-refresh. I know that a fuller conference is in some ways a healthier conference, and I still maintain that if talks have to be trimmed at future meetings, established players like myself should take the hit so students and early-career-researchers can have some runway, but I still appreciated the more relaxed pace of this meeting.

3. Food and drink

Food and drink service was probably the best that I have experienced at a paleo conference, full stop. I wish I had taken a photo of the ranked rows of coffee cups on saucers, because they never ran out. I don’t think we ever ran out of coffee, either. A lunch of sandwiches, crisps, veggies, and hummus (edit: and cheese, lots of beautiful cheese!) was provided on Thursday and Friday all three days of the conference, and from what I saw, the lunches ran down to a bare handful of sandwiches at the very end but didn’t quite run out — and this was after everyone had ample opportunity to go back for more. Simply an outstanding job.

If I had one quibble, it was that the bar at Cowes Yacht Haven opened about five minutes before the start of Don Henderson’s Fox Lecture on Wednesday evening, without warning and after a lot of people (Mike and me included) had brought in drinks from outside, which we were then told we couldn’t drink on the premises. I realize that the opening and closing of the yacht club bar was probably outside the control of the organizers, but it was an annoyance for those of us who wanted to have a drink with the evening lecture.

4. Exhibitors

I admit to being disappointed when I realized that the meeting would be at Cowes rather than near the Dinosaur Isle museum in Sandown. We did get to visit the museum for the Tuesday evening icebreaker, but other than that we were in a different town entirely. The organizers’ clever solution was to bring the fossils to the paleontologists: several local collectors brought fossils for us to pore over on breaks and during poster time. This was particularly great for Mike, Jessie, and me, since so many of the fossils on display were from sauropods. Jessie and I were able to recognize neural canal ridges in the vertebrae of a rebbachisaurid for the first time, and we were able to use a brachiosaur caudal to demonstrate the ridges to Femke Holwerda, who then told us she’d seen them in a cetiosaur caudal. So our research made meaningful advancements because of the specimens on display, and we made useful contacts.

Speaking of Femke, her big Patagosaurus redescription has been accepted for publication at an OA outlet, so look for that most-welcome work in the not-too-distant future.

There were also paleoartists among the exhibitors, including John Sibbick, Mark Witton, and Luis Rey, among others, including some local artists. I picked up a nice print of a hand-drawn sauropod caudal by Trudie Wilson (this Trudie Wilson, not that Trudie Wilson, although I’m sure she’s a wonderful person too), which I need to do a whole post about, and will soon. I can’t remember now who proposed it, but someone remarked in one of the open sessions about how nice it was to have so much paleoart on display, and that maybe that was something that future meetings could lean into, including having paleoartists give talks about their art. That’s not unprecedented — John Conway and Bob Nicholls have both given presentations on paleoart at previous meetings, either in regular sessions or at evening social functions — but it is a great idea, and one I heartily endorse.

5. Proximity to everything else

Mike did sterling work finding an AirBnB house for a bunch of us (Mike, Darren, Mark Evans, Femke Holwerda, Jeff Liston, Mark Witton, Georgia Witton-Maclean, and Vicki and London and me) that was 300 feet from the entrance to Cowes Yacht Haven and about 700 feet from the banquet hall where the talks were held. I don’t think I’ve ever had such a short walk between my lodgings and the talk venue, even when I’ve stayed in the hotel where the conference was being held. There was also a Sainsbury’s grocery store, a bank of ATMs, and a bunch of restaurants within, seriously, a two-minute walk of the venue. I realize that this was also a lucky circumstance, not readily repeatable for other meetings that take place in museums or university lecture halls at some remove from commercial districts, but it sure was nice. If you had ten minutes, you could legit pop out to Sainsbury’s for some crisps or a beer, and be back at your seat with time to spare.

6. Loot

This one is purely personal, and mostly outside the organizers’ control. (Although they did carelessly put those exhibitors right in the path of my wallet, which fortunately was only running at about Category 3 this trip.) I’m only listing it here to guilt me into finishing the post (or posts) about the items I acquired on the trip, but folks, I did all right. More on that later.

So, a huge thank-you to the organizers of this year’s SVPCA for pulling off such a comfortable and enjoyable meeting. It was a gem. For more on what it was like, please see this post by Emma Nicholls, Deputy Keeper of Natural History at London’s Horniman Museum. If you know of other post-SVPCA conference reviews or retrospectives, please post them in the comments.

I’ll have more to say about both of these in the near future, but for now suffice it to say that this (link):

and this (link):

are available for your perusal. Not just the abstracts, but the slide decks as well, just as Mike did for his talk on Jensen’s Big Three sauropods (link).

Jessie is also posting her talk a few slides at a time on her Instagram, with some helpful unpacking, so that’s worth a look even if you have the slides already. That stream of posts starts here.

My friend and frequent collaborator Jessie Atterholt has her office in the next building over from mine. When you walk in, you see something that looks approximately like this. Not exactly like this, because I took these photos in February and she’s changed a few things (and I’m rubbish about getting stuff posted in a timely fashion).

The last time I showed an office full of amazing stuff like this, it was Peter Dodson’s. It will come as no surprise that Jessie was Peter’s student at UPenn before she went to Berkeley for her PhD.

The far case holds mostly books and skulls. Dr. A has her own plastination setup for making preserved organs and organisms, and the snake on the second shelf here is one that she prepped herself. One side of the snake still has the skin on, the other half has been skinned to show the muscles. This is crunch week for me so I don’t have time to ID all of the stuff, but alert readers should have no problem spotting some digitally-resurrected Haplocanthosaurus bits.

Mostly skulls on the middle rack. The sirenian skull on the second shelf and the cave bear on the fourth are both casts, but almost everything else is real bone. The bighorn sheep on the middle shelf is a natural mummy.

Here’s a close-up of the top shelf. Other than some 3D-printed human skull bones sitting in front of the brain slice on the left, everything here is real bone, including the lion, baboon, and human skulls, and the giraffe cervicals winding across the top. Jessie’s been collecting since she was a kid and the African megafauna are gifts from a globe-trotting family friend.

The upper shelves here have quite a few of Jessie’s plastinated specimens, both whole organisms and things like hearts and kidneys from various critters.

A close-up of some of Jessie’s coolest anatomical preparations. In back is an internal cast of the lungs and bronchial tree of a cat. The baby rattlesnake died after eating a proportionally gigantic lizard — I was dumb and forgot to flip the snake over to show the lizard inside, plastinated along with its predator. The ground squirrel on the right is another half-fleshed, half-skinned plastinate, and the mouse up front is a classic dissection presentation, preserved forever through plastination.

I’ve heard it said that the difference between a collector and a hoarder is curation. As someone who definitely lurks more on the hoarder end of that spectrum (to paraphrase Dave Barry, if you could see my office you’d be blinded or driven insane), I’m pretty darned jealous of both the breadth of Jessie’s collection, and the skill and taste with which it is displayed. She’s featured some of these specimens on her Instagram, which I strongly recommend.

In a word, amazingly. After 6 days (counting public galleries last Sunday), 4300 photos, 55 videos, dozens of pages of notes, and hundreds of measurements, we’re tired, happy, and buzzing with new observations and ideas.

We caught up with some old friends. Here Mike is showing an entirely normal and healthy level of excitement about meeting CM 584, a specimen of Camarasaurus from Sheep Creek, Wyoming. You may recognize this view of these dorsals from Figure 9 in our 2013 PeerJ paper.

We spent an inordinate amount of time in the public galleries, checking out the mounted skeletons of Apatosaurus and Diplodocus (and Gilmore’s baby Cam, and the two tyrannosaurs, and, and…).

I had planned a trip to the Carnegie primarily to have another look at the Haplocanthosaurus holotypes, CM 572 and CM 879. I was also happy for the chance to photograph and measure these vertebrae, CM 36034, which I think have never been formally described or referred to Haplocanthosaurus. As far as I know, other than a brief mention in McIntosh (1981) they have not been published on at all. I’m planning on changing that in the near future, as part of the larger Haplocanthosaurus project that now bestrides my career like a colossus.

The real colossus of the trip was CM 555, which we’ve already blogged about a couple of times. Just laying out all of the vertebrae and logging serial changes was hugely useful.

Incidentally, in previous posts and some upcoming videos, we’ve referred to this specimen as Brontosaurus excelsus, because McIntosh (1981) said that it might belong to Apatosaurus excelsus. I was so busy measuring and photographing stuff that it wasn’t until Friday that I realized that McIntosh made that call because CM 555 is from the same locality as CM 563, now UWGM 15556, which was long thought to be Apatosaurus excelsus but which is now (i.e., Tschopp et al. 2015) referred to Brontosaurus parvus. So CM 555 is almost certainly B. parvus, not B. excelsus, and in comparing the specimen to Gilmore’s (1936) plates of CM 563, Mike and I thought they were a very good match.

Finding the tray of CM 555 cervical ribs was a huge moment. It added a ton of work to our to-do lists. First we had to match the ribs to their vertebrae. Most of them had field numbers, but some didn’t. Quite a few were broken and needed to be repaired – that’s what I’m doing in the above photo. Then they all had to be measured and photographed.

It’s amazing how useful it was to be able to reassociate the vertebrae with their ribs. We only did the full reassembly for c6, in part because it was the most complete and perfect of all of the vertebrae, and in part because we simply ran out of time. As Mike observed in his recent post, it was stunning how the apatosaurine identity of the specimen snapped into focus as soon as we could see a whole cervical vertebra put back together with all of its bits.

We also measured and photographed the limb bones, including the bite marks on the radius (above, in two pieces) and ulna (below, one piece). Those will of course go into the description.

And there WILL BE a description. We measured and photographed every element, shot video of many of them, and took pages and pages of notes. Describing even an incomplete sauropod skeleton is a big job, so don’t expect that paper this year, but it will be along in due course. CM 555 may not be the most complete Brontosaurus skeleton in the world, but our ambition is to make it the best-documented.

In the meantime, we hopefully left things better documented than they had been. All of the separate bits of the CM 555 vertebrae – the centra, arches, and cervicals ribs – now have the cervical numbers written on in archival ink (with permission from collections manager Amy Henrici, of course), so the next person to look at them can match them up with less faffing about.

We have people to thank. We had lunch almost every day at Sushi Fuku at 120 Oakland Avenue, just a couple of blocks down Forbes Avenue from the museum. We got to know the manager, Jeremy Gest, and his staff, who were unfailingly friendly and helpful, and who kept us running on top-notch food. So we kept going back. If you find yourself in Pittsburgh, check ’em out. Make time for a sandwich at Primanti Bros., too.

We owe a huge thanks to Calder Dudgeon, who took us up to the skylight catwalk to get the dorsal-view photos of the mounted skeletons (see this post), and especially to Dan Pickering, who moved pallets in collections using the forklift, and moved the lift around the mounted skeletons on Tuesday. Despite about a million ad hoc requests, he never lost patience with us, and in fact he found lots of little ways to help us get our observations and data faster and with less hassle.

Our biggest thanks go to collections manager Amy Henrici, who made the whole week just run smoothly for us. Whatever we needed, she’d find. If we needed something moved, or if we needed to get someplace, she’d figure out how to do it. She was always interested, always cheerful, always helpful. I usually can’t sustain that level of positivity for a whole day, much less a week. So thank you, Amy, sincerely. You have a world-class collection. We’re glad it’s in such good hands.

What’s next? We’ll be posting about stuff we saw and learned in the Carnegie Museum for a long time, probably. And we have manuscripts to get cranking on, some of which were already gestating and just needed the Carnegie visit to push to completion. As always, watch this space.

References

If you were curious about the Wedel et al. presentation on the Snowmass Haplocanthosaurus at the 1st Palaeo Virtual Congress but didn’t attend the event, it is now preserved for posterity and freely available to the world as a PeerJ Preprint (as promised). Here’s the link.

I’ll have much more to say about this going forward, but for now here are slides 20 and 21 on the intervertebral joint spaces. This is obviously just the same vert cloned three times and articulated with itself. With the digital rearticulation of the reconstructed and retrodeformed caudal series still in progress, we cloned caudal 3, the only vertebra that preserves both sets of zygapophyses, to get a rough estimate of the sizes and shapes of the soft tissues that filled the intervertebral spaces and neural canal.

The reconstructed intervertebral discs (in blue) are very crude and diagrammatic. The reason I’m putting these particular slides up is to get the cited references out in the open on the blog, to start correcting the misapprehension that all non-mammalian amniotes have exclusively synovial intervertebral joints (see the discussion in the comments on this post). In the list below I’m including Banerji (1957), which is not cited in the presentation but which I did cite in that comment thread; it’s an important source and at least for now it is a free download. These refs are just the tip of a very big iceberg. One of my goals for 2019 is to do a series of posts reviewing the extensive literature on amphiarthrodial (fibrocartilaginous) intervertebral joints in living lepidosaurs and birds. Stay tuned!

And please go have a look at the presentation if you are at all interested or curious. As we said in the next to last slide, “this research is ongoing, and we welcome your input. If there are facts or hypotheses we haven’t considered but should, please let us know!”

References

The 1st Palaeontological Virtual Congress is underway now, and will run through December 15. Mike and I have two presentations up:

“What do we mean by the directions ‘cranial’ and ‘caudal’ on a vertebra?” by Mike and me, which consists of a video Mike made presenting a slide show that he put together. The presentation sums up our thinking following the series of vertebral orientation posts here earlier this summer and fall, which are all available here.

“Reconstructing an unusual specimen of Haplocanthosaurus using a blend of physical and digital techniques” by me and a gang of WesternU-based collaborators, including Jessie Atterholt and Thierra Nalley, both of whom you saw in our recent pig-hemisecting adventures. Almost everything I’ve written on this blog about Haplocanthosaurus in 2018 was part of the run-up to this presentation (except, somewhat ironically, the post about pneumaticity), which also includes quite a bit that I haven’t put on the blog yet. So even if you follow SV-POW!, the 1PVC slideshow should have plenty of stuff you haven’t seen yet.

IF you can see it–you have to be a registered 1PVC ‘attendee’ to log in to the site and see the presentations. So probably you are either already registered and this post is old news, or not registered and this post seems useless. Why would I bother telling you about stuff you can’t see?

The answer is that neither Mike or I intend for our work to disappear when 1PVC comes to an end on December 15. Both of us are planning to put our abstracts and slide decks up as PeerJ Preprints, which is our default move for conference presentations these days (e.g., this, this, and this). I believe Mike is also going to post his video to YouTube. So the work will not only live on after the congress is over, it will jump to a much broader audience. We’re looking forward to letting everyone see what we’ve been up to, and I’m sure we’ll have some more things to say here when that happens.

So, er, go see our stuff if you’re a 1PVC attendee, and if you’re not, hang in there, we’ll have that stuff out to you in a few days. UPDATE: The Haplo presentation is up now (link).

In a comment on the last post, Mike wrote, “perhaps the pneumaticity was intially a size-related feature that merely failed to get unevolved when rebbachisaurs became smaller”.

Caudal pneumaticity in saltasaurines. Cerda et al. (2012: fig. 1).

Or maybe pneumaticity got even more extreme as rebbachisaurids got smaller, which apparently happened with saltasaurines  (see Cerda et al. 2012 and this post).

I think there is probably no scale at which pneumaticity isn’t useful. Like, we see a saltasaurine the size of a big horse and think, “Why does it need to be so pneumatic?”, as if it isn’t still one or two orders of magnitude more massive than an ostrich or an eagle, both of which are hyperpneumatic even though only one of them flies. Even parakeets and hummingbirds have postcranial pneumaticity.

Micro CT of a female Anna’s hummingbird. The black tube in the middle of the neck is the supramedullary airway. Little black dots in the tiny cervical centra are air spaces.

We’re coming around to the idea that the proper way to state the dinosaur size question is, “Why are mammals so lousy at being big on land?” Similarly, the proper way to state the pneumaticity question is probably not “Why is small sauropod X so pneumatic?”, but rather “Why aren’t some of the bigger sauropods even more pneumatic?”

Another thought: we tend to think of saltsaurines as being crazy pneumatic because they pneumatized their limb girdles and caudal chevrons (see Zurriaguz et al. 2017). Those pneumatic foramina are pretty subtle – maybe their apparent absence in other sauropod clades is just because we haven’t looked hard enough. Lots of things have turned out to be pneumatic that weren’t at first glance – see Yates et al. (2012) on basal sauropodomorphs and Wedel and Taylor (2013b) on sauropod tails, for example.

Back of the skull of a bighorn sheep, showing the air spaces inside one of the broken horncores.

Or, even more excitingly, if the absence is genuine, maybe that tells us something about sauropod biomechanics after all. Maybe if you’re an apatosaurine or a giant brachiosaurid, you actually can’t afford to pneumatize your coracoid, for example. One of my blind spots is a naive faith that any element can be pneumatized without penalty, which I believe mostly on the strength of the pneumatic horncores of bison and bighorn sheep. But AFAIK sauropod girdle elements don’t have big marrow cavities for pneumaticity to expand into. Pneumatization of sauropod limb girdles might have come at a real biomechanical cost, and therefore might have only been available to fairly small animals. (And yeah, Sander et al. 2014 found a pneumatic cavity in an Alamosaurus pubis, but it’s not a very big cavity.)

As I flagged in the title, this is noodling, not a finding, certainly not certainty. Just an airhead thinking about air. The comment thread is open, come join me.

References

In my recent visit to the LACM herpetology collection, I was interested to note that almost every croc, lizard, and snake vertebra I saw had a pair of neurovascular foramina on either side of the centrum, in “pleurocoel” position. You can see these in the baby Tomistoma tail, above. Some vertebrae have a big foramen, some have a small foramen, and some have no visible foramen at all. Somehow I’d never noticed this before.

This is particularly interesting in light of the observation from birds that pneumatic diverticula tend to follow nerves and vessels as they spread through the body. Maybe we find pneumatic features where we do in dinosaurs and pterosaurs because that’s where the blood vessels were going in the babies. Also, these neurovascular foramina in extant reptiles are highly variable in size and often asymmetric – sound familiar?

It should. Caudal pneumaticity in the tail of Giraffatitan MB.R.5000. Dark blue vertebrae are pneumatic on both sides, light blue vertebrae only have fossae on the right side. Wedel and Taylor (2013b: Figure 4).

I am starting to wonder if some of the variability we associate with pneumaticity is just the variability of soft tissue, full stop. Or if pneumaticity is variable because it developmentally follows in the footsteps of the blood vessels, which are themselves inherently variable. That seems like a promising line of inquiry. And also something I should have though of a lot sooner.