As noted in the last post, Matt and I are off to spend a week at the Carnegie Museum from 11th-15th March. We expect to see many, many fascinating specimens there: far more than we’ll be able to do proper work on in the five days we have. So our main goal is to exhaustively document the most important specimens that we see, so we can work on them later after we’ve got home. I think of this as the “harvesting” phase of research, with the grinding and baking to follow.

I was going to write a checklist for myself, to ensure that I cover all the bases and we don’t find ourselves in six months’ time looking at our records and saying “I can’t believe we forgot to do X for this specimen” — because, believe me, we have spent far too much of our lives doing this already. But then I realised I should share it with the world, in case it’s helpful to others, too.

So here’s what to do when dealing with, for example, an apatosaurine cervical like this one. Let me know in the comments if I forgot anything!

BYU 20178, cervical vertebra from an apatosaurine sauropod. ventral view, anterior to the left. Note that the scalebar is held at approximately half the height of the vertebra; and that the catalogue card is in view and legible, giving a record who collected the specimen, when, and where.

Sketch the specimen, even if (like me) you are a terrible artist. The process of sketching forces you to really look at it — at each part of it in turn — and often results in you noticing something you would otherwise have missed. It would be worth doing this even if you immediately threw the sketch away: but don’t do that, because you’re going to want to …

Measure the specimen, using a tape measure, digital calipers or both as appropriate. You want to get at least all the measurements that you’ll include in a formal description — total length, total height, width across zygapophyses, etc. — but it’s often useful to also get other, more obscure measurements, just to make sure you’ve got your head around the shape. For example, in the vertebra above, you might measure the diagonal distances from the anteriormost projection of each cervical rib to to opposite side’s posterolateralrmost part of the centrum. You record measurements in a table in your notebook, but some measurements are hard to describe: so just write them straight onto your sketch. To keep things straight, it can be useful to do the sketch in one colour and the measurements in another; or the sketch in pencil and the measurements in pen.

Now we come to photography. You want a lot of different kinds of photo, so lets consider them separately.

Take photographs of the specimen with its specimen label, ideally from several different aspects. This will make it easy to remember later which specimen is which. In a typical museum visit — especially a reconnaisance visit like our upcoming Carnegie trip — you’re going to see a lot of different specimens, and when you revisit your photos in six months it’ll be hard to keep them all straight. Make it easy on yourself. Also: the specimen label often contains other  useful information such as the quarry where the specimen was found. Capture that. Get a good close-up photo of the label alone, to ensure all the text is captured cleanly.

Take photographs from the cardinal directions. To illustrate a specimen nicely in a descriptive paper, you will at minimum want photos from anterior, posterior, dorsal, ventral and left and right lateral aspects (or as many of these are possible to obtain: you can’t always turn big specimens). Since these are the photos you’re likely to use in a publication, take extra care with these. Set up a plain-coloured background when possible so it’s easier to crop out later. Set up the best lighting you can. Take each photo several times so you can keep the best one. Use a tripod if you have one. (For much more on this, see Tutorial 8 on how to photograph big bones.)

Take photographs with a scalebar. This will give you a way to sanity-check your measurements later. Think carefully about scalebar placement. If you put it on top of the specimen so it obscures part of the fossil, be sure that’s not your only photo from that aspect: you won’t want to be left without good images of the whole bone. A scalebar placed on top of the specimen will appear larger than the same scalebar placed on the floor or the bench next to the specimen, thanks to perspective, which means your measurements are more trustworthy than photos of the scalebar. If you can easily arrange for it to be raised to half the total height of the specimen, you’ll get a more honest reading.

Photograph individual features of the bone with some kind of note. The reason I say “with some kind of note” is that I have hundreds of close-up photos of bits of sauropod vertebra which I evidently took in the hope of highlighting some specific bit of morphology, but I have no idea what morphology. Get a scrap of paper and scribble something like “big nutrient foramina”, draw an arrow on it, and place the scrap on the bone so that the arrow points at the feature. Take a photo; then remove the paper and take another photo. The first one is your note to yourself; the second is the raw material for an illustration that you might prepare later, highlighting the relevant feature in a more elegant way.

Do a video walkaround with narration. For some reason, we didn’t start doing this until very recently, but it’s a great way to get a rough-and-ready reminder of important aspects of the specimen. You can just do this with a phone, moving it around the specimen, pointing to interesting bits and saying things about them. Here’s an example of Matt pointing out some features of the preserved cervical vertebrae of Suuwassea, and here he is again pointing out how pelican vertebrae are made of nothing.

Take a shedload of undifferentiated photos from every possible angle. Your goal here is that you’ll be able to use photogrammetry later to make a 3D model of the fossil. I admit to my shame that I’ve still never successfully done this — but thanks to the kindness of my good friend Heinrich Mallison, who is an expect in this area, I do have some fine models, including the Xenoposeidon model that was published as a supplementary file to my 2018 paper. Even if you don’t have access to someone as helpful as Heinrich, it’s worth getting these comprehensive photo-sets because photogrammetry software is likely to get progressively easier to use. Hopefully in a couple more years there will be nothing to it but loading a bunch of photos and pressing a button.


Up till here, we’ve been concentrating on gathering information about the specimen in a form that we’ll be able to return to later and use in comparisons and illustrations. But we can do more than that now we’re here with the physical specimen:

Look at the bone texture. Figure out how much of it is real, and how much is reconstructed — a particular problem with older specimens. Keep an eye out for rugosities for muscle and ligament attachments, smooth areas and pockets for pneumatic diverticula (or fat pads in boring mammal verts), and any odd growths that might be ossified soft tissues or pathological reactive bone growth. These kinds of things are often much easier to see in the actual specimens than in even the very best photographs.

Check for areas where the specimen is under-prepared. It’s very common for a neural canal to remain filled with matrix — and easy to spot, so in a sense not a problem. But how often is a pneumatic feature obscured because it’s still full of matrix? This is probably part of the reason that caudal pneumaticity so often goes unobserved, and it will very often obscure foramina within the neural canal. Similarly, I don’t know whether the huge club on the end of the right cervical rib of NHMUK PV R173b (formerly BMNH R173b) is pathological bone or a mineral concretion, because all I have to go from is my lame photos. I should have figured that out while I was with the actual specimen.

Discuss the specimen with a friend. I just can’t overstate how important this is. When Matt and I visit a collection together, we discover much, much more than twice as much as either of us would alone. Isaac Asimov is said to have observed “The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka!” (I found it!) but “That’s funny …””. Whether or not he ever actually said it (it’s not in any of his written works) it’s certainly true that the key moment in investigating a specimen is frequently when one person says “Hey, take a look at this”. Two minds can spark off each other in a way that a single mind can’t.


Last of all, it’s worth giving a little bit of thought to the possibility that you’ll one day be doing publicity for this specimen. So:

Get someone to take photos of you with the specimen. You’ll need them for press releases and media packs. I’ve only once in my life been in physical proximity with the Brontomerus specimen: during the three-day 2007 visit when I did much of the descriptive work for the paper. Idiotically, although I was there with three colleagues (Matt, Randy Irmis and Sarah Werning), I didn’t get anyone to take a photo of me with the material. So when we needed a photo for the publicity:

The Brontomerus mcintoshi holotype specimen OMNH 27761-27800, 61248 and 66429-66432 with the authors of the paper that described it. Back row (L to R): Mike Taylor, Matt Wedel, Rich Cifelli.

There was no good way to get it. I certainly wasn’t going to fly back out to the USA just to get a photo. So we got our Emmy award-winning special-effects-wizard friend Jarrod Davis to photoshop me into a photo that the museum had been able to take of Matt and Rich. (You can see the evidence here and here if you want to see how it was done. And, yes, before he could even start composing me in, Jarrod had to rescue a ludicrously under-exposed base image.)

Much better to avoid such nonsense. Get good photos of you with the specimens, like the one at the top of the Sauropocalypse post, and then if you ever need ’em you’ve got ’em.

 

Advertisements

Having benefitted so hugely from 3D models that Heinrich Mallison made for me — most notably, the Xenoposeidon model that is the supplementary data file for the recent preprint — I realised the time has come for me to learn to do this for myself. To that end, I am going to read all the tutorials he’s written on the subject. This page is a link-farm to those tutorials, which I made for my own benefit, but which I hope others will also benefit from.

There is also Heinrich’s paper, with Oliver Wings, Photogrammetry in paleontology – a practical guide (Mallison and Wings 2014), which he announced in its own blog-post.

Reference

 

I’ve done a few book signings now and here’s my checklist of stuff to bring. The first three items on the list are asterisked because they may be provided by the venue, but they may not. Sometimes the venue will have tables for rent but not for loan. Don’t assume, do check in advance.

  1. Table.*
  2. Chair.*
  3. Tablecloth.* Yes, really. Even if the table is really nice, it will look even better with a tablecloth. Black, so it won’t show ink spots or stains, and long enough to reach the floor so visitors don’t have to look at whatever weird thing your legs and feet look like when you’re sitting in a chair. (There’s no tablecloth in the photo above because I had loaned it to Brian Engh to cover the much uglier table he had next to mine.)
  4. Books.
  5. Book stand, to hold a display copy of the book vertically, and – assuming the book is illustrated – open to a good ‘splash’ page.
  6. Clear plastic standees for signs, book covers, notes. Having the list price and the discounted price (assuming they’re available at a discount) is good. If there are positive quotes from reviews, put ’em on a sign.
  7. Blue Sharpies for signing books. Blue because it stands out, Sharpies because they’re permanent and the ink dries wicked fast. If you have doubts about the ink bleeding through, test in advance.
  8. Post-It notes: for people to write down names so you spell them correctly in the inscriptions, for you to write notes to send with people, to put names on reserved or pre-paid books, and for the thousand or so unforeseen circumstances where having a sticky note might be useful.
  9. Scissors: for opening boxes, cutting plastic off books, cutting paper signs to size on short notice, etc.
  10. Masking tape for fixing up ad-hoc signs, repairing boxes, hanging things from the wall or table, etc.
  11. Business cards to easily hand out email address and URLs.
  12. Full-size envelope or wallet for holding bills: full-size so you don’t have to fold and unfold bills, zipper top with no flap for easy access and equally easy closure, opaque sides so people can’t see how much is in there, and ideally a vibrant color so it will be hard for you to lose and equally hard for someone to swipe without drawing attention.
  13. Folder with discount fliers (or info fliers) for people who can’t buy a book right then. Don’t underestimate how useful these can be. There are a host of reasons why a potential buyer might not want, or be able, to purchase a book right that moment. Maybe they want their hands free as they’re walking around, if it’s an event with other exhibitors. Maybe they have no cash and can’t get a signal for PayPal (in which case, you probably won’t be able to get a signal for your Square card reader). Maybe they just want time to think about it. Whatever the reason, a tactile reminder of your book is a helpful thing to be able to send away with a potential buyer.
  14. Speaking of payment, set up for yourself a PayPal.me link, like this one. It’s fast and free, and the URL will be short enough that you can write it on a Post-It. At one of my signings this spring, there was no cell or wifi access inside the building. But a customer was able to go outside, get a signal, pay me using my PayPal.me link, get a screenshot of the confirmation, come back inside and show me the confirmation, and get their book. Seriously, do this.
  15. Plastic dinosaurs to set on the table and serve as long-distance visual cues. Don’t work on dinosaurs? Find some physical object related to your book to set on the table.
  16. Hand specimens for guests to examine while their books are being signed. For me that’s a chunk of petrified wood from the Morrison Formation, and a sectioned ostrich vertebra showing the internal structure.

In the photo up top, all of the little fiddly stuff – items 7-13 – is hidden behind one of the stacks of books, or behind the open book when the stacks get depleted. You can hide all kinds of mess behind a stack of books and still have a nice presentation.

I keep all of this stuff in a cardboard box that is clearly labeled “Book Signing”. So when an event comes along, all I have to grab are the books and that box and I’m good to go.

If you have further suggestions for improvement, let me know!

Step 1: Include the Share-Alike provision in your Creative Commons license, as in the mysteriously popular CC BY-SA and CC BY-NC-SA.

Step 2: Listen to the crickets. You’re done. Congratulations! No-one will ever use your silhouette in a scientific paper, and they probably won’t use your stuff in talks or posters either. Luxuriate in your obscurity and wasted effort.

Pachyrhinosaurus canadensis by Andrew A. Farke, CC BY 3.0, courtesy of PhyloPic.org.

Background

PhyloPic is the incredibly useful thing that Mike Keesey made where makers upload silhouettes of organisms and then people can use them in papers, posters, talks, on t-shirts, bumper stickers, and so on.

At least, they can if the image license allows it. And tons of them don’t, because people include the stupid Non-Commercial (NC) and even stupider Share-Alike (SA) provisions in their image licenses. (Need a refresher on what those are? See the tutorial on licenses.)

Why are these things dumb? Well, you could make a case for NC, but it will still probably kill most potential uses of your images. Most journals are run by companies — well, most are run by incredibly rapacious corporations that extract insane profits from the collective suckerhood that is academia — and using such an image in a for-profit journal would break the Non-Commercial clause. Even open-access journals are a bit murky.

But Share-Alike is way, way worse. What it means is that any derivative works that use material released under CC-BY-SA have to be released under that license as well. Share-Alike came to us from the world of software, where it actually has some important uses, which Mike will expand upon in the next post. But when it comes to PhyloPic or pretty much any other quasi-academic arena, including the Share-Alike provision is misguided.

As of this writing, PhyloPic has two silhouettes of Panphagia. I can actually show you this one, because it doesn’t have the Share-Alike license attached. The other one is inaccessible. Image by Ricardo N. Martinez and Oscar A. Alcober, CC BY 3.0, courtesy of PhyloPic.org.

Why not Share-Alike?

Why is Share-Alike so dumb for PhyloPic? It’s a viral license that in this context accomplishes nothing for the creator. Because the downstream material must also be CC BY-SA (minimally, or CC BY-NC-SA), almost any conceivable use is prevented:

  • People can’t use the images in barrier-based journals, because they’re copyrighted.
  • People can’t use the images in almost all OA journals, because they’re CC BY, and authors can’t just impose a more restrictive license on them willy-nilly.
  • People can’t use the images in their talks or posters, unless they want to make their talks and posters CC BY-SA. Even people who do release their talks and posters out into the wild are probably going to use CC BY if they use anything; they care about being cited, not about forcing downstream users to adopt a pointlessly restrictive license.
  • People probably can’t use the images on t-shirts or bumper stickers; at least, I have a hard time imagining how a physical object could meet the terms of CC BY-SA, unless it’s being given away for free. And even if one could, most downstream creators probably won’t want the headache — they’ll grab a similar image released under a less restrictive license and move on.
  • I can’t even blog the CC BY-SA images because everything we put on this blog is CC BY (except where noted by a handful of more restrictive museum image use policies), and it would more than a little ironic to make this one post CC BY-SA, which it would have to be if it included CC BY-SA images.

You may think I’m exaggerating the problem. I’m not. If you look at the Aquilops paper (Farke et al. 2014), you’ll see a lot of ceratopsian silhouettes drawn by Andy Farke. We were making progress on the paper and when it came time to finish the illustrations, most of the silhouettes we needed had the Share-Alike provision, which made them useless to us. So Andy drew his own. And while he was doing that, I took some of my old sauropod drawings and converted them to silhouettes and uploaded them. Both of us used CC BY, because all we care about is getting cited. And now people are using — and citing! — Andy’s and my drawings in preference to others, some arguably better (at least for the sauropods), that have pointlessly restrictive licenses.

So we have this ridiculous situation where a ton of great images on PhyloPic are essentially unusable, because people put them up under a license that sounds cool but actually either outright blocks or at least has a chilling effect on almost any conceivable use.

Is this a good silhouette of Camarasaurus? Maybe, maybe not. But that’s beside the point: this is currently the only silhouette of Camarasaurus on PhyloPic that you can actually use. By Mathew Wedel, CC BY 3.0, courtesy of PhyloPic.org.

What I do about this

Here’s my take: I care about one thing and one thing only, which is credit. All I need is CC BY. If someone wants to take my stuff and put it in a product and charge a profit, I say go for it — because legally every copy of that product has to have my name on it somewhere, credited as the creator of the image. I may not be making any money off that product, but I’m at least getting exposure. If I go CC BY-NC, then I also don’t get any money, and now I don’t even get that exposure. Why would I hack my own foot off like that? And I don’t use CC BY-SA because I don’t write software, so it has only downsides to offer me.

Now, there are certainly artists in the world with sufficient talent to sell t-shirts and prints. But even for them I’m skeptical that CC BY-NC has much to offer for their PhyloPic silhouettes. I know we’re all nuts around here for monochrome filled outlines of dead animals, but let’s be real, they’re a niche market at best for clothing and lifestyle goods. Personally I’d rather get the citations than prevent someone in Birmingham or Bangkok from selling cladogram t-shirts with tiny copies of my drawings, and I think that would still be true even if I was a professional artist.

What you should do about this

I suspect that a lot of people reading this post are dinosaur enthusiasts. If you are, and you’d like to get your name into published scientific work (whether you pursue writing and publishing yourself or not), get drawin’, and upload those babies using CC-BY. Make sure it is your own original work, not just a skin thrown over someone else’s skeletal recon, and don’t spam PhyloPic with garbage. But if you can execute a technical drawing of a critter, there’s a good chance it will be used and cited. Not only because there are still holes in PhyloPic’s coverage, but because so many otherwise great images on PhyloPic are locked up behind restrictive licenses. To pick an example nearly at random, PhyloPic has two silhouettes of Pentaceratops, and both of them are useless because of the Share-Alike provision in their licenses. You have an opportunity here. Don’t tarry.

If you already uploaded stuff to PhyloPic using CC BY-SA for whatever reason (it sounded cool, Joe Chill murdered your folks, you didn’t realize that it was academic reuse equivalent of radioactive syphilis), change it or replace it. Because all it is doing right now is driving PhyloPic users to other people’s work. Really, honestly, all you are doing is wasting your time by uploading this stuff, and wasting the time of PhyloPic users who have to hover over your pictures to find out that they’re inaccessible.

You don’t get any credit if no-one ever uses your stuff. Or, more precisely, you get 100% of a pie that doesn’t exist. That’s dumb. Stop doing it.

Reference

Farke, A.A., Maxwell, W.D., Cifelli, R.L., and Wedel, M.J. 2014. A ceratopsian dinosaur from the Lower Cretaceous of Western North America, and the biogeography of Neoceratopsia. PLoS ONE 9(12): e112055. doi:10.1371/journal.pone.0112055

A few months ago I got an email from Nathan Myers, who asked me:

Do you have advice for someone who wants to spin up a new OA journal? Is there automation for the boring parts? Is someone you know well versed in what to do?

In many ways, I’m the wrong person to ask: I’ve never started a journal, OA or otherwise, nor even served on an editorial board.

But, hey, I’m not one to let something like that stop me. So here’s what I told Nathan. I’m sure I missed a lot of important possibilities: please point them out in this comments. I’ll try to keep this post updated as the landscape changes.


There are several good options at this point.

The simplest and cheapest is probably to use Annotum, a WordPress plugin that helps with the review workflow. I’ve not used it myself, but I know it’s what PLOS Currents uses, so it’s obvious battle-ready. I’m not sure but I think you can use it as a theme in a wordpress.com-hosted free blog.

Scholastica offers very low-cost support for running an overlay journal, as for example the recently launched Discrete Analysis: see Tim Gowers’ blog-post about the new journal.

Open Journals Systems is a widely used software package for running open-access journals — IIRC they have more that 10,000 running installations worldwide. I’ve not used it, but it evidently has what it takes.

If you have some funding to cover production charges, or are able to charge an APC, you can use a full-service option from a low-cost OA publisher such as Ubiquity Press.

PeerJ’s system is widely liked — very easy for authors and reviewers to use. Its software is all on GitHub, though I think some work would be needed to tie it all together. If you have the software engineering chops, this may be the best option for performance/price ratio.

What else?

Wedel 2005 Morrison sauropod cervicals 1 - Diplodocus

When I was back in Oklahoma in March, I met with Anne Weil to see some of the new Apatosaurus material she’s getting out of her Homestead Quarry. It’s nice material, but that’s a post for another day. Anne said something that really resonated with me, which was, “I love it when you guys post about vertebral morphology, because it helps me learn this stuff.” Okay, Anne, message received. This will begin to make things right.

Wedel 2005 Morrison sauropod cervicals 2 - Barosaurus and centra shapes

I spent a week at BYU back in 2005, collecting data for my dissertation. One of the first things I had to do was teach myself how to identify the vertebrae of different sauropods, because BYU has just about all of the common Morrison taxa. These are the notes I made back then.

Wedel 2005 Morrison sauropod cervicals 3 - Brachiosaurus and Apatosaurus

I always planned to do something with them – clean them up, get them into a more usable form. There are a lot of scribbly asides that are probably hard for others to read, and it would be more useful if I put the easily confused taxa next to each other – Barosaurus next to Brachiosaurus, for example. And I didn’t go into serial changes at all.

Wedel 2005 Morrison sauropod cervicals 4 - Camarasaurus and Haplocanthosaurus

Still, hopefully someone will find these useful. If there are things I missed or got wrong, the comment thread is open. And if you want all four spreads in one convenient package, here’s a PDF: Wedel 2005 notes on Morrison sauropod cervicals

Mike and I leave for the Sauropocalypse tomorrow. I’m hoping to post at least a few pretty pictures from the road, as I did for the Mid-Mesozoic Field Conference two years ago. Stand by…

Saurischian laminae and fossae v2 - Adam Marsh 2015

[Hi folks, Matt here. I’m just popping in to introduce this guest post by Adam Marsh (UT Austin page, LinkedIn, ResearchGate). Adam is a PhD student at UT Austin’s Jackson School of Geosciences, currently working for a semester as a Visiting Student Researcher at my old stomping ground, Berkeley’s UCMP.  Adam’s been working at Petrified Forest National Park in the summers and most of his research is on the Navajo Nation in Arizona. His major interest is in how we perceive extinctions in the fossil record. Specifically, he’s exploring the geochronology of the Glen Canyon Group to look at the biotic response to the end-Triassic mass extinction. He’s also working on an overhaul of the early saurischian dinosaurs of western North America – hence this post. It’s timely because I was just talking in the last post about putting together infographics to spread your ideas; here Adam’s very nice diagram serves as a quick guide and pointer to several papers by Jeff Wilson and colleagues. Many thanks to Sarah Werning for suggesting that Adam and I get acquainted over vertebrae. Update the next day: both the diagram above and the PDF linked below have been updated to fix a couple of typos. Also, there are now black and white versions – see below.]

– – – – – – – – – –

If you’re like me, you don’t count sheep when you fall asleep, you count laminae. These struts of bone and their affiliated fossae connect and span between major structural features on vertebral neural arches such as prezygapophyses, postzygapophyses, parapophyses, diapophyses, hyposphenes, hypantra, and the neural spine. Presumably, laminae bracket and fossae house outgrowths of pneumatic diverticula from the respiratory system, which has been covered extensively on this blog in sauropodomorph dinosaurs.

Talking about these complicated structures is cumbersome; they’ve been called buttresses, ridges, struts, etc. throughout descriptive skeletal literature. But what we call things is important, especially when we introduce laminae and other vertebral structures to the rigors of phylogenetic systematics, where homologous apomorphies reign supreme. In order to avoid arguing about whether one structure is called the potato or the tomato, Jeff Wilson and others introduced a strategy of naming vertebral laminae (Wilson, 1999) and the fossae (Wilson et al., 2011) that they surround using the same vertebral landmarks that most tetrapod anatomists agree upon (see the parade of –apophyses above). The process is very simple. Vertebral laminae are named for the two structures that they connect; the prezygodiapophyseal lamina (prdl) connects the prezygapophysis and the diapophysis, so each neural arch will have two prdls. Vertebral fossae are named for the two major laminae that constrain them; the prezygocentrodiapophyseal fossa (prcdf) opens anterolaterally and is delineated dorsally by the prezygodiapophyseal lamina and ventrally by the anterior centrodiapophyseal lamina. Again, each neural arch will have two prcdfs. Those of you who are black belt vertebral anatomists, to borrow a favorite phrase from my advisor, might be interested in serial variation and how these structures change up and down the vertebral column. Until I get my act together and publish some cool new saurischian data, I will refer you to Wilson (2012). [We’ve also touched on serial variation in laminae in this post and this one. – MJW]

Saurischian laminae and fossae v2 bw - Adam Marsh 2015

Same thing in black and white, with labels

 

You might have noticed that the names are a mouthful and take up their fair share of typed characters. In my research of early saurischian dinosaurs, I’ve run across quite a few of these laminae everywhere from herrerasaurids to sauropodomorphs to coelophysoids to Dilophosaurus. Even though I’ve drawn, photographed, and written about various laminae and fossae, I still need to remind myself of what goes where and what it’s called. Believe me, vertebral lamina nomenclature does not lend itself well to Dem Bones covers. As a result, I’ve put together a reference figure that might be useful for those of you who are dealing with this or even teaching it to students. At the very least, you can put it on the ceiling above your bed so that it’s the first thing you see when you open your eyes in the morning.

Four main vertebral laminae are present plesiomorphically in archosaurs: the anterior and posterior centrodiapophyseal laminae, the prezygodiapophyseal lamina, and the postzygodiapophyseal lamina. This means that the prezygocentrodiapophyseal, postzygocentrodiapophyseal, and centrodiapophyseal fossae are present, and sometimes the top of the transverse process is concave between the neural spine and the zygapophyses to form the spinodiapophyseal fossa. I know that a certain sister group of Sauropodomorpha can get disparaged around these parts, but the truth is that theropods build long necks, too, and sometimes in very different ways than sauropodomorphs. When you are writing about the various vertebral buttresses and chonoses, don’t get frustrated with the names, because Wilson and his colleagues have actually made it much easier for us to talk to one another about presumably homologous structures without needing an additional degree in civil engineering.

– – – – – – – – – –

Here’s the figure again in PDF form: Marsh, Adam 2015 saurischian laminae and fossae diagram v2

And in black and white for those who prefer it that way: Marsh, Adam 2015 saurischian laminae and fossae diagram v2 bw

References