December 11, 2014
As I mentioned in my first post on Aquilops, I drew the skull reconstructions that appear in figure 6 of the paper (Farke et al. 2014). I’m writing this post to explain that process.
We’ve blogged here before about the back-and-forth between paleontologists and artists when it comes to reconstructing and restoring extinct animals (example 1, example 2). Until now, I’ve always been the guy making suggestions about the art, and asking for changes. But for the Aquilops project, the shoe was on the other foot: Andy Farke was my ‘client’, and he had to coach me through drawing a basal ceratopsian skull – a subject that I was definitely not familiar with.
I started from the specimen, OMNH 34557, which is more complete than you might think at first glance. The skull is folded over about 2/3 of the way up the right orbit, so in lateral view it looks like the top of the orbit and the skull roof are missing. They’re actually present, just bent at such a sharp angle that they’re hard to see at the same time as the lateral side of the skull.
I also used a cast skull of Archaeoceratops as a reference – it’s clear from what we have of Aquilops that the two animals were pretty similar.
I started with this pencil outline on a piece of tracing paper.
And then I went right ahead and stippled the whole thing, without showing it to Andy until I was done. Yes, that was dumb. Noe the lack of sutures in this version.
I added sutures and sent it off to Andy, who sent it back with these suggested changes. At this point I realized my error: I had already spent about a day and a half putting ink on the page, and I’d have to either start all over, or do a lot of editing in GIMP. I picked the latter course, since there were plenty of areas that were salvageable.
Next I did something that I’d never done before, which is to redraw parts of the image and then composite them with the original in GIMP. Here’s are the redrawn bits.
With those bits composited in, and a few more tweaks to sutures, we got to this version, which was included in the submitted manuscript.
Then we brought Brian Engh in to do the life restorations. When Brian takes on a project, he does his homework. If you’ve seen his post on painting Aquilops, you know that all of the ferns in the Cloverly scene are based on actual fossils from the Cloverly Formation. Brian came to Claremont this summer and he and Andy and I spent most of a day at the Alf Museum looking at the specimen and talking about possible layouts for the full-body life restorations. He took a bunch of photos of the specimen while he was there, and a day or two later he sent us this diagram. He’d chopped up his photos of the skull to produce his own undistorted version to guide his painting, and in doing so he’d noticed that I had the line of the upper jaw a bit off.
That required another round of digital revisions to fix. It ended up being a lot more work than the earlier round of edits in GIMP, because so many features of the skull had to be adjusted. I ended up cutting my own skull recon into about 8 pieces and then stitching them back together one by one. Here’s what the image looked like about halfway through that process. The back of the skull, orbit, and beak are all fixed here, but the snout, cheek, and maxilla don’t yet fit together.
After a little more work, I got the whole thing back together, and this is the final version that appears in the paper. It is not perfect – the area in front of the orbit where the frontal, nasal, maxilla, and premaxilla come together is a bit dodgy, and I’m not totally happy with the postorbital. But eventually you have to stop revising and ship something, and this is what I shipped.
I did the dorsal view after the submitted version of the lateral view was finished. It went a lot faster, for several reasons:
- Most of the gross proportional issues were already sorted out from doing the lateral view first.
- The bilateral symmetry didn’t cut down on the number of dots but it did cut the conceptual workload in half.
- I did all my roughs in pencil and didn’t start inking until after we had almost all of the details hashed out.
I did have to revise the dorsal view after getting feedback from Brian about the lateral view, but that revision was pretty minor by comparison. I stretched the postorbital region and tinkered a bit with the face and the frill, and both of those steps required putting in some new dots, but it was still just one afternoon’s worth of work. Here’s the final dorsal recon:
In addition to the Life Lessons already noted in this post, I learned (or rather relearned) this important principle: if you do a big drawing and then shrink it down to column width, fine errors – a shaky line here, an ugly dot there – get pushed down below the threshold of perception. But there’s a cost, too, which is that uneven stippling becomes more apparent. I was skipping back and forth a lot between 25% image scale to see where the problem areas were, and 200% to revise the lines and dots accordingly.
All in all, it was a fun project. It was my most ambitious technical illustration to date, I learned a ton about ceratopsian skulls, and it was nice to get to make at least one substantial contribution to the paper.
Now, here’s the take-away: this is my reconstruction, and both of those words are important. “Reconstruction” because it has a lot of extrapolation, inference, and sheer guesswork included. “My” because you’re getting just one possible take on this. You can download the 3D files for the cranium and play with them yourselves. I hope that other artists and scientists will use those tools to produce their own reconstructions, and I fully expect that those reconstructions will differ from mine. I look forward to seeing them, and learning from them.
For other posts about my stippled technical illustrations, see:
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
June 18, 2014
Check out this beautiful Lego Diplodocus:
(Click through for the full image at full size.)
I particularly like the little touch of having of bunch of Lego Victorian gentleman scientists clustered around it, though they’re probably a bit too big for the skeleton.
This is the work of MolochBaal, and all rights are reserved. You can see five more views of this model in his Flickr gallery. I especially admire how he’s managed to get the vertebral transitions pretty smooth, the careful use of separate radius/ulna and tibia/fibula, and the use of a transparent brick in the skull to represent the antorbital fenestra.
The forefeet are wrong — their toes should not be splayed out — but you can’t blame MolochBaal for that, as he was copying the mounted CM 84/94 cast in the Madrid museum.
June 16, 2014
We feature a lot of Brian Engh’s stuff here–enough that he has his own category. But lately he has really been outdoing himself.
The wave of awesome started last year, when Brian started posting videos showing builds and suit tests for monsters–monster suits, monster puppets, monster you-name-its. Like this monster-sculpting timelapse from last August:
And this suit test from last October:
Brian even wrote a blog post about how he builds monsters.
Things really ramped up this May with the release of “In Mountains”, the first video in a three-part series from Brian’s Earth Beasts Awaken album (which is badass, and available for free here).
If you’re thinking that the Mountain Monster has some Estemmenosuchus in its background, you are correct–that astonishing real-world critter was one of Brian’s inspirations, among many others.
More awesomeness is coming in July, when the next video, “Call to Awaken”, is slated to be released. Here’s a teaser:
I have even more exciting Brian-Engh-related news, but I am not at liberty to discuss that just yet. Hopefully sometime this fall. Stay tuned, true believers. UPDATE: Now I’m at liberty to discuss it!
I think it’s fair to say that this “bifurcation heat-map”, from Wedel and Taylor (2013a: figure 9), has been one of the best-received illustrations that we’ve prepared:
Back when the paper came out, Matt rashly said “Stand by for a post by Mike explaining how it came it be” — a post which has not materialised. Until now!
This illustration was (apart from some minor tweaking) produced by a program that I wrote for that purpose, snappily named “vcd2svg“. That name is because it converts a vertebral column description (VCD) into a scalable vector graphics (SVG) file, which you can look at with a web-browser or load into an image editor for further processing.
The vertebral column description is in a format designed for this purpose, and I think it’s fairly intuitive. Here, for example, is the fragment describing the first three lines of the figure above:
Taxon: Apatosaurus louisae
Specimen: CM 3018
Taxon: Apatosaurus parvus
Specimen: UWGM 155556/CM 563
Taxon: Apatosaurus ajax
Specimen: NMST-PV 20375
Basically, you draw little ASCII pictures of the vertebral column. Other directives in the file explain how to draw the various glyphs represented by (in this case) “Y”, “V”, “u”, and “n”.
It’s pretty flexible. We used the same program to generate the right-hand side (though not the phylogenetic tree) of Wedel and Taylor (2013b: figure 2):
The reason I mention this is because I released the software today under the GNU General Public Licence v3.0, which is kind of like CC By-SA. It’s free for anyone to download, use, modify and redistribute either verbatim or in modified form, subject only to attribution and the requirement that the same licence be used for modified versions.
vcd2svg is written in Perl, and implemented in part by the SVG::VCD module, which is included in the package. It’s available as a CPAN module and on GitHub. There’s documentation of the command-line vcd2svg program, and of the VCD file format. Also included in the distribution are two documented examples: the bifurcation heat-map and the caudal pneumaticity diagram.
Folks, please use it! And feel free to contribute, too: as the change-log notes, there’s work still to be done, and I’ll be happy to take pull requests from those of you who are programmers. And whether you’re a programmer or not, if you find a bug, or want a new feature, feel free to file an issue.
A final thought: in academia, you don’t really get credit for writing software. So to convert the work that went into this release into some kind of coin, I’ll probably have to write a short paper describing it, and let that stand as a proxy for the actual program. Hopefully people will cite that paper when they generate a figure using the software, the way we all reflexively cite Swofford every time we use PAUP*.
Update (12 April 2014)
- Swofford, D. L. 2002. PAUP*: phylogenetic analysis using parsimony (* and other methods). Sinauer Associates, Sunderland, MA.
- Wedel, M.J., and Taylor, M.P. 2013. Neural spine bifurcation in sauropod dinosaurs of the Morrison Formation: ontogenetic and phylogenetic implications. Palarch’s Journal of Vertebrate Palaeontology 10(1): 1-34. ISSN 1567-2158.
- Wedel, Mathew J., and Michael P. Taylor. 2013. Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus.PLOS ONE 8(10):e78213. 14 pages. doi:10.1371/journal.pone.0078213 [PDF]
January 24, 2014
Here’s a nice thing: friends and relatives just assume (correctly) that I will want whatever dead animals they find. So I was not completely surprised when I got a call from my brother Ryan (pillager of the Earth) asking if I wanted a dead mouse he’d found mummified at the back of an unused cupboard. Happily this was over the holidays so I could get the specimen in person and not have to deal with mailing it.
This was not destined to be my mummified mouse, however. My son, London, has started a collection of his own. One of the first real skulls in his collection was that of a rat that we found dead in our front yard last year. I cut off its head and we boiled and cleaned the skull together (I still need to post about that). Then we mounted it in a clear plastic bottle that had previously contained toothpicks, so he could take it for show-and-tell. Last fall a second rat turned up dead in the yard; that one is still in the freezer, awaiting complete skeletonization. The mystery of the plague of dead rats was solved when we got home one evening and found our cat, Moe, in the front yard with only the hind leg of a third rat hanging out of his mouth. If I could just train him to kill them and not eat them, we could make a rat army…
Funny side-note: we keep Skulls Unlimited catalogs around for leisure reading. London was looking through one not long after we prepped his rat skull and he saw that you could get a fully-prepared natural bone skull for about twenty bucks. That price seems about right to me, given the amount of work and care that has to go into cleaning, but London was outraged: “Why would people pay TWENTY DOLLARS for a rat skull when they could just clean their own!?”
That’s my boy! I didn’t have the heart to tell him that some people don’t have a ready supply of rats lying around. He’s not old enough to understand that level of deprivation.
So, obviously the mummified mouse was going to show-and-tell. But I didn’t want it to get destroyed. My cheap and low-tech solution was to get a rigid plastic display box from the local hobby store ($5.99 for a two-pack) and stuff it with cotton balls. We cleared some of the cotton around the skull first so it would be more visible. Knowing how third-graders can be when exciting things get passed around, I also glued the lid on. The mouse and the cotton balls are completely immobile even when violently shaken, and hopefully they’ll stay that way indefinitely. I forgot to include a scale bar in either of these photos or to measure my damned murine, but the box lid is 5 inches on side. HeroClix Knifehead showed up because kaiju are notorious attention hogs.
Now, to see if Mousenkhamun can survive the rigors of third grade. I’ll keep you posted.
December 18, 2013
When we last left my better half, Dr. Vicki Wedel, she was helping to identify a Jane Doe who had been dead for 37 years by counting growth rings in the woman’s teeth. That case nicely illustrated Vicki’s overriding interest: to advance forensic anthropology by developing new methods and refining existing ones. To that end, for the past few years she has been working with her PhD advisor, Dr. Alison Galloway at UC Santa Cruz, to revise and update Alison’s 1999 book, Broken Bones: Anthropological Analysis of Blunt Force Trauma. The revised and much expanded (504 pages vs 371) second edition, co-edited by Vicki and Alison, came out Monday (Amazon, Amazon.co.uk).
You can read the whole table of contents on Amazon (click to look INSIDE!), but the short short version is that the book has three major sections. The first covers the science and practice of trauma analysis (pp. 5-130), and the second classifies hundreds of common fractures throughout the skeleton, with illustrations (pp. 133-313). The chapters in these sections were all written by Vicki, Alison, and another of Alison’s former students, Dr. Lauren Zephro, solo and in varying combinations. Lauren, whom I always think of as “the Amazon cop”, is a 6-foot blackbelt forensic anthropologist for the Santa Cruz County Sheriff’s Office. If push came to shove I have no doubt that she could beat me to death with her bare hands and then produce a technical analysis of my corpse.
The final section (pp. 314-410) consists of nine case studies contributed by forensic anthropologists, pathologists, medical examiners, forensic and medical artists, and a DoD casualty analyst, based across the Anglophone world from Hawaii to Scotland. There’s some grim stuff in there: trauma to the homeless and elderly, from intimate partner violence, and from child abuse. It’s gut-churningly awful that the defenseless suffer from bone-breaking violence; it’s always been amazing to me that people like Vicki, Alison, Lauren, and the other contributors have both the courage to face these horrors and the technical chops to make the unspeakable solvable.
Beyond that unavoidable darkness, if you’re interested in the many, varied, and often just plain weird ways in which people die, the book is a treasure trove. There’s an elderly woman lying on her deathbed for six years, slowly turning into a natural mummy… (wait for it) …while her daughter went on living in the same house. There’s a classification of plane crashes with a description of what human remains will be found and over what area. There are people hit by trains; the funniest line in this very serious book is the deadpan and unsurprising, “The typical pedestrian hit by a train is male and often highly intoxicated.”
That’s from the top of page 122. At the bottom of the same page is my one contribution to the book, which also appears as the cover art (yeah, nepotism, whatcha gonna do). There’s a story behind this. This guy–yes, male, dunno if he was intoxicated–was hit by a train and his head was sheared in half, with the somewhat fractured but mostly intact facial skeleton separated by a lot of missing bone from the occipital region. With no way to obtain the deceased guy’s permission to use his mortal remains in the book, Alison and Vicki didn’t feel comfortable including their photos, so I spent a weekend bashing out a technical drawing for them to use instead. That reawakened my interest in pen-and-ink work and led to the dödö pöst.
I should say two things right here: first, that yes, I am hijacking the rest of the post to talk about myself. (Is anyone really surprised? I thought not.) Second, that I have had no training and possibly my stippling violates Art Rules or best practice guidelines of which I am ignorant. But I hope it also illustrates what can be achieved in a couple of days, with about $15 worth of supplies, by a guy whose only rule is “möre döts”.
So anyway, if you’re curious, here’s the method I use for my pen-and-ink illustrations:
- Get a decent-sized photo of the object to be drawn. I usually roll with $2 8x10s from MalWart, in this case one for each half of the skull.
- Tape the photo down to your work surface. I have a large, incredibly hard, perfectly smooth cutting board that I use for this, but in a pinch you could use just about anything, including just a larger piece of paper. Cardboard off the backs of desk calendars is nice.
- Over the photo, tape down a piece of tracing paper.
- Lightly trace the outline of the photo and all the major details in pencil.
- Once you’ve gone as far as you can with that, peel up one side of the tracing paper, unstick the photo from the work surface, and remove it. Stick the tracing paper back down the work surface.
- Using the uncovered photo as a reference, pencil in any other salient details by eye. Also contour lines for shadows. All of the pencil lines are going to be erased later, so don’t be shy.
- Whenever you decide you’re done with the pencil, get a good pen and start tracing, directly over the pencil lines. I tend not to be too persnicketty about my tools but decent pens are a real help here. For these recent works, I picked up a three-pack of beige-tubed Micron pens for $7 (this set).
- In all of the following pen-related steps, be careful to keep your big stupid hand and arm off the wet ink you just laid down–one careless smear can ruin a few hours’ work. Having a work surface that you can rotate is nice, so your pen hand can approach the drawing from any angle. Anytime I have to lay my hand on the drawing, I put down a piece of clean scrap paper first. Even if the underlying ink is dry, it just feels like a smart precaution.
- Once the lines are on, add döts to taste. With a little experimentation, you can get patterns of dots to not only indicate light and dark but also suggest textures. Different pen tips and amounts of pressure will yield dots of different sizes, which can also be useful. Dense, overlapping dots can produce an effect similar to scratchboard. BTW, sometimes I do “gear down” and place each dot with thought and care, but in the dense sections I just rat-a-tat-tat like a Lilliputian jackhammer. Try different speeds and see what you can tolerate.
- When you’re done dötting, at least to a first approximation, and you’re dead certain the ink is all dry, get a decent eraser and erase all of the pencil lines. I used one of those clicky mechanical erasers because it was cheap and soft enough to not tear up the paper.
- Re-ink any lines lightened by the erasing. I find that the döts are usually unaffected, but lines are often knocked down a bit by the eraser work. I suppose it would be cleaner to just draw natively in pen, with no prior pencilling and therefore no erasing, but the few times I’ve tried it, it hasn’t gone well. YMMV. If you’re drawing a 3D solid, this is a good time to employ an old illustrator’s trick, which is to make the bottom outline heavier and darker than the rest, to subtly convey a sense of weight.
- Scan, touch up as needed in GIMP, post to blog, bask in self-admiration.
In this case I had a few more steps, which consisted of making variants of the drawing and test-driving them by Vicki and Alison so they could pick their favorites.
This is just embarrassing: after scanning the two drawings and doing a little touch-up, I just scooted them together until they looked like a skull. The problem is that the occiput is nowhere near anatomical position. See that flange of bone above the ear-hole, pointed down and right at a 45-degree angle? That’s the back end of the zygomatic arch, and it should be aimed at the forward stump of the arch, which is just down and back from the eye socket.
Here’s the B version, where I was working entirely off of the zygomatic arch ends, and trying to get the skull into anatomical position. Scientifically this is probably the best variant I produced (I’m not claiming it’s the best possible), but aesthetically it’s a little crowded.
I’ll spare you versions C-E, all of which just scooted the back end of the skull around in an attempt to find a balance between scientific and aesthetic concerns. Here’s the winning F version, which got used for the figure, and became the seed variant for the cover.
For the cover, we tried a lot of things, including the white skull on a black background, and one that was simply inverted from the figure. By this point the publisher had sent Vicki some test versions of the cover, and I thought it would be cool if the drawing was in the same color as the cover text, so I sampled that color from the publisher’s sample cover image and applied it to all of the drawn bits. They knocked it down a few tones for the printed version, so happily it’s not this garish.
Incidentally, I had never tried to replace a bunch of discontinuous areas of the same color with another color in GIMP, so I had to look it up. The two key steps are Select > By color, with the threshold set to zero (or not, if you want to grab a bunch of related colors at once), and “Fill whole selection” in the Bucket tool. Hat tip to this dude and his commenters.
One last step: I thought the bare, unfilled yellow version looked too flat, so I tried different levels of fill to make the skull pop out from the background. I didn’t use bucket fill here–too fiddly with so many dots and edges. Instead I created a new layer of solid yellow and dropped the opacity to 17%. Then went to the drawing layer and used the magic wand tool to select the whole non-skull background. Then popped back to the yellow layer and cleared that selection, leaving yellow fill only in the boundaries of the skull outline. I also tried 10% and 25% opacity for the fill layer, but 10% was too subtle and 25% was starting to swamp some of the detail in the drawing. Between goofing around with colors and opacity levels we went through 10 versions at this stage, of which the one above is the ultimate champion.
So, that’s how the cover art came to be. Back to the book. There’s a bibliography with 1237 references (Vicki knows), and an index. The book is hardbound, with a printed cover and no dustjacket, and IMHO reasonably priced at $65, currently a few bucks less on Amazon. You probably already know whether you want a copy. If so, do the right thing–it’s not too late to get it by Christmas.
October 22, 2013
It shouldn’t come as a huge surprise to regular readers that PeerJ is Matt’s and my favourite journal. Reasons include its super-fast turnaround, beautiful formatting that doesn’t look like a facsimile of 1980s printed journals, and its responsiveness to authors and readers. But the top reason is undoubtedly its openness: not only are the article open access, but the peer-review process is also (optionally) open, and of course PeerJ preprints are inherently open science.
It’s a baby Parasaurolophus, but despite being a stinkin’ ornithopod it’s a fascinating specimen for a lot of reasons. For one thing, it’s the most complete known Parasaurolophus. For another, its young age enables new insights into hadrosaur ontogeny. It’s really nicely preserved, with soft-tissue preservation of both the skin and the beak. The most important aspect of the preservation may be that C-scanning shows the cranial airways clearly:
This makes it possible for the new specimen to show us the ontogenetic trajectory of Parasaurolophus — specifically to see how its distinctive tubular crest grew.
But none of this goodness is the reason that we at SV-POW! Towers are excited about this paper. The special sauce is the ground-breaking degree of openness in how the specimen is presented. Not only is the paper itself open access (and the 28 beautiful illustrations correspondingly open, and available in high-resolution versions). But best of all, CT scan data, surface models and segmentation data are freely available on FigShare. That’s all the 3d data that the team produced: everything they used in writing the paper is free for us all. We can use it to verify or falsify their conclusions; we can use it to make new mechanical models; we can use it to make replicas of the bones on 3d printers. In short: we can do science on this specimen, to a degree that’s never been possible with any previously published dinosaur.
This is great, and it shows a generosity of spirit from Andy Farke and his co-authors.
But more than that: I think it’s a great career move. Not so long ago, I might have answered the question “should we release our data?” with a snarky answer: “it depends on why you have a science career: to advance science, or to advance your career”. I don’t see it that way any more. By giving away their data, Farke’s team are certainly not precluding using it themselves as the basis for more papers — and if others use it in their work, then Farke et al. will get cited more. Everyone wins.
Open it up, folks. Do work worthy of giants, and then let others stand freely on your shoulders. They won’t weigh you down; if anything, they’ll lift you up.
Farke, Andrew A., Derek J. Chok, Annisa Herrero, Brandon Scolieri, and Sarah Werning. 2013. Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids. PeerJ 1:e182. http://dx.doi.org/10.7717/peerj.182