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.


  • 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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In a move that will surprise no-one who’s been paying attention, my and Matt’s presentation of vertebral orientation at the 1st Palaeo Virtual Congress is now up as a PeerJ preprint. Sadly, with the end of the conference period on 15th December, the page for my talk has been deleted, along with some interesting comments. But here at SV-POW!, we have no truck with ephemerality, hence this more permanent manifestation of our work.

Matt’s preprint consists of the abstract, and has the slide deck as a supplementary data file. That’s what he submitted to the conference, with attendees invited to page through it. By contrast, I recorded a video of my talk. I am trying to get that attached to my preprint, but as things stand it’s not there because it’s too big (at 65 Mb).

Meanwhile — and indeed in perpetuity — you can just watch it on YouTube, where I also uploaded it. In the end, that may be a more practical way of making video available anyway, but I do want the preservational benefit of lodging it with a preprint.

Remember, we’re working on the paper in the open. We’d love to get input from you all, and especially from anyone who’s run into this problem before with other taxa. Please, if you have fifteen minutes spare, watch the talk and leave any comments you have: here, on the preprint, on the YouTube page, or as issues in the GitHub tracker!


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!”


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).

Just a quickie today. The 1st Palaeontological Virtual Congress is happening this December. Where? Everywhere! Well, everywhere with internet service. There is no physical place to go attend. Talks, posters, discussions, etc. will happen online. Consequently, registration is extremely affordable at a whopping 5 Euros. Circulars are here if you want to know more.

I’m “going”, probably to present on the Haplocanthosaurus project–which only occasionally dips into realspace anyway–with a bunch of the folks who made it happen.

A couple of things to note:

  • The abstract deadline has been pushed back from Sept. 20 to Oct. 8, so you’ve got a little time yet.
  • [UPDATE Sept. 17 – I shoulda waited a couple of days. The PayPal link is live and working. I know because I just used it.] Originally they were only accepting registration payments by bank transfer. I guess that’s a trivially easy thing in Europe to do from your smartphone. A lot of banks here in the States make you go to the bank in person, wait in line, see a teller, and fill out paperwork. Kind of a huge hassle for a measly 5 EUR. I brought this up with the organizing committee and they were already moving on getting a PayPal account set up to process registration payments. That should happen soon – I’ll update the post when it does.

So, er, see you there?