I was back in Utah the week before last, looking for monsters with Brian Engh and Jessie Atterholt. It was a successful hunt – more about that another time.
We made a run to Fruita, Colorado, to visit Dinosaur Journey. I was just there in May, picking up Haplocanthosaurus caudals for CT scanning (and other fun things). We picked up another specimen this time, for a different project – more on that in another post, too.

Not this one, but like this one. An apatosaurine middle caudal vertebra, MWC 5742, in left lateral view.
There’s a nice ceratopsian exhibit up at Dinosaur Journey right now, with cast skulls from many of the new ceratopsians that have been described in the past couple of decades. My near-favorites were Zuniceratops and Diabloceratops, both of which are small enough that they must have been adorable in life (think pony-sized and big-horse-sized, respectively).
My absolute favorite, of course, was this little thing:
I can tell you exactly how Aquilops came to be on display there. Julia McHugh printed a copy of the holotype, because it’s freely available to the world. And she used Brian’s Aquilops head recon in the signage (correctly, with attribution), because it’s also freely available to the world. In fact, I’ve seen Aquilops on display at several museums now for just those reasons. So, folks, if you want your critters to be seen, make them open. Hiring a paleoartist to do some awesome artwork that can be released under a CC-BY license (because you paid them, not because you asked them to give their art away for “exposure”) is a huge help.
We had to geek out a little about unexpectedly finding ‘our’ dinosaur on display:
But of course it is not our dinosaur anymore – that’s the whole point. Aquilops belongs to the world.
For more on our trip, see Jessie’s posts here, here, and here.
Cabinet of curiosities: a visit to Peter Dodson’s office
June 17, 2018
I’ve known who Peter Doson was since I was nine years old. A copy of The Dinosaurs by William Stout and William Service, with scientific content by Peter, showed up at my local Waldenbooks around the same time as the New Dinosaur Dictionary – much more on The Dinosaurs another time. Then when I started doing research as an undergrad at the University of Oklahoma, Peter’s chapter on sauropod paleobiology in The Dinosauria (Dodson 1990) was one of the first things I read. At the SVP banquet in 2000, I ran into Peter and he shook my hand and said, “Sauroposeidon rocks!” I managed not to swoon – barely.
When I was in Philadelphia this March, Peter invited me to the UPenn vet school for an afternoon. He gave me a tour of the building with its beautiful lecture halls and veterinary dissection lab, and then we spent a couple of hours rummaging around in his office. That was one of the highlights of the trip, because it turns out that Peter and I are both comparative anatomy junkies. He’s been at it for longer, and he has more regular access to dead critters and more space to display them, so his collection puts mine to shame. But he kindly let me play with study whatever I wanted.
In fact, he went farther than that: he quizzed me. A lot. I take it that it’s a right of passage for people coming through Peter’s office. It was an enjoyable challenge, and I got photos of a few quiz items so you can play, too. This transversely-sectioned skull was one of the first mystery specimens. I figured it out pretty quickly, for reasons I’ll reveal in a future post. Can you? Post your IDs in the comments.
I don’t remember all of the quiz items. One of them was the dark skull lying upside down behind the ratite skeleton in the photo up top. I had to figure that one out without picking it up, so you have about as much information as I did. We’ll call that one quiz item #2. Embiggenate for all the clues you’ll need.
This wasn’t a quiz item, just something cool: the skull of a large dog with the top of the cranium removed. In the paired cavities at the top, we’re looking down through the frontal sinuses to see the respiratory turbinates in the nasal cavities. The single large space behind is the braincase. At the very front, in the shadowed recess, you can see the cribriform plate of the ethmoid bone, perforated with dozens of holes to let the olfactory nerve endings through from the back of the nasal cavities. We have the same thing on a smaller scale a centimeter or two behind our brows, and oriented horizontally. But what really drew my attention were the linear arrays of paired foramina arcing across the floor of the braincase – holes to let cranial nerves and the internal jugular veins out of the skull, and the internal carotid arteries in. We have the same structures in our heads, of course, but the layout isn’t as neat – our big brains, bent forward at such a sharp angle from the spinal cord, have squished things around a bit.
Here are more skulls, garnished with a human femur and a ratite pelvis and synsacrum. Peter quizzed me on the Archaeoceratops (front) and Auroraceratops (back) skulls on the far right. I IDed them correctly, but only because I spent some quality time with the Alf Museum’s casts when I was reconstructing the skull of Aquilops. On the far left is an alligator skull with injected arteries, which is definitely worth a closer look.
Here’s a dorsal view of the injected alligator skull. The arteries have been injected with red resin, and then all of the soft tissue has been macerated away, leaving just the bone and the internal cast of the arterial tree. Some of the midline bone has been removed here to reveal the courses of the cerebral, ethmoid, and nasal arteries. Also note the artery looping around in the left supratemporal fenestra.
Here’s a look into the right side of the back of the skull, where the lateral wall of the braincase has been Dremeled away to show the course of the internal carotid artery. It’s a very cool demonstration of a bit of anatomy that I had never seen before. For more on cranial blood vessels in crocs, check out the obscenely well-illustrated recent paper by Porter et al. (2016).
To my chagrin, that’s all the good photos I got from Peter’s office – we were too busy passing specimens back and forth and frankly geeking out like a couple of kids. One of my favorite specimens from his office was the mounted foot skeleton of a horse, which Jessie Atterholt had prepared for him when she was his student at UPenn. It’s such a cool preparation that it captured my imagination, and when I got back I warned Jessie that if she didn’t get her own articulated horse foot posted soon, I was going to make something similar for myself and steal her thunder. A couple of months later, her horse foot is up on Instagram – I featured it in this post – and my cow foot is still sitting in pieces, waiting for me to put it together. Here’s a shot of Jessie’s, to hopefully prod me into action:
I didn’t get all of Peter’s quiz questions correct. I knew that the endocast of the pharyngeal pouch in a horse was an endocast, but of what I didn’t know, although I did correctly identify the hyoid apparatus of a horse, mounted separately. And there was a partial cetacean jaw that I misidentified as a shark (in my defense, it was from one of the small, short-faced weirdos). Still, Peter said that I’d done as well as anyone else ever had. That was nice to hear, but I was already happy to have gotten to see and talk about so many cool things with a fellow connoisseur. Thanks, Peter, for a wonderful afternoon, and for permission to post these pictures. I am looking forward to a rematch!
References
- Dodson, P. 1990. Sauropod paleoecology. In: D.B. Weishampel, P. Dodson, P., & H. Osmolska, (eds), The Dinosauria, 402-407. University of California Press, Berkeley.
- Porter, W.R., Sedlmayr, J.C. and Witmer, L.M., 2016. Vascular patterns in the heads of crocodilians: blood vessels and sites of thermal exchange. Journal of Anatomy 229(6): 800-824.
- Stout, W., Service, W., and Preiss, B. 1984. The Dinosaurs: A Fantastic View of a Lost Era. Bantam Dell Publishing Group, 160pp.
So, here’s a cool thing that happened at Norwescon. On Saturday afternoon, there was an autograph signing session. Probably to the surprise of no-one, a lot more people were interested in having things signed by the other two guests of honor, Galen Dara and Ken Liu, than by me. But happily I was situated between them so I coasted a bit on the interest they drew. There was quite a bit of downtime in the two-hour session, so I had the chance to chat with both Galen and Ken. That was actually a highlight of the con for me – I was hoping for a chance to get to know my fellow guests of honor a bit, instead of just passing them in the hallways as we all went off to our separate scheduled activities.
Whenever Galen Dara wasn’t signing autographs, she was drawing. Makes sense, right? You probably don’t get to be as professionally successful as she is if making art isn’t compulsive. And it was just my luck that the proximate cool thing around to draw was the skull of Aquilops – I was signing prints of my skull recon, and I had along the reconstructed cast skull that I use for education and outreach. So I had the fairly trippy experience of watching an award-winning artist at the top of her game draw ‘my’ critter.
As you can see from Galen’s Instagram, she draws and paints a lot of skulls, and she spends a lot of time exploring the geometric underpinnings of skulls. She warned me at the outset that her Aquilops skull would be more impressionistic than photo-realistic – her interpretation of Aquilops as organic art. I think it looks pretty great; I have to trace stuff to get the proportions that close on the first go. And as I recently mentioned in another post, it’s always mesmerizing for me to see how a visual artist can conjure form, weight, and texture one pencil-stroke at a time.
Many thanks to Galen for permission to post these pics, and for her interest in my favorite non-sauropod.
Old drawings (of heads)
June 25, 2017
I was organizing my files in DropBox and I found a folder of old drawings I’d almost forgotten about. I drew this back in the late 90s. It was used on a t-shirt by the OU Zoology Department. I got the general idea of making a head out of animals, and the specific idea of using a butterfly wing for the ear, from Wayne Douglas Barlowe’s cover for the novel Wild Seed by Octavia Butler. The snake I stole from ancient Egypt. I think everything else is in there just because I thought it was cool. Note that inverts, fish, herps, birds, and mammals are all represented, with a good balance of aquatic, terrestrial, and volant forms. It looks awfully hippie-dippie from 20 years out, but heck, what doesn’t?

“Solitude” by Mathew Wedel. CC BY-NC 4.0.
Well, this, I suppose.
I drew this about the same time. I was reading The Gnostic Gospels by Elaine Pagels and lots of stuff about ancient monastic traditions and thinking that if the world is an illusion that must be penetrated, then the evidence of one’s senses can only mislead. Also, Vicki was working for the state medical examiner in Oklahoma City and they used wooden dowels to represent the paths of bullets when reconstructing the skulls of those killed by gunfire. So here’s the skull of a monk, with all of the lethal pathways of distraction and temptation clearly marked as such. At last he can contemplate the eternal mysteries in perfect solitude.
Obviously I didn’t get on board the world-is-an-illusion, sensation-is-bad train – skewed pretty hard in the opposite direction, in fact. Possibly because years earlier the Chessmen of Mars by Edgar Rice Burroughs had shown me that pursuing ‘pure’ intellectual and spiritual inquiry would ultimately lead one to a pathetic existence as a disembodied head living in a cave (high culture, meet low culture). Anyway, whatever interest I might have had in that philosophy I exorcised through this drawing. Stripped of any art-making-a-point baggage, I still think it’s pretty bitchin’. I should make t-shirts.
Actually, I probably will make t-shirts of this one if there’s any interest. Hence the CC BY-NC license I put on it, as opposed to the normal CC BY for almost everything else on this site. Look at me, boldly experimenting with new licenses.
This, obviously, is a lot more recent. I was collating all of my scanned drawings and I realized that I’d gone to the trouble of drawing the cranium and lower jaw of Aquilops separately, but I’d never posted the version from before I composited them back into articulation. It is very unlike me to do work and then hide it, so here it is.
It wasn’t until I the post mostly written that I realized that all three drawings are of heads, none of them are saurischians (although the first includes a saurischian, but not the cool kind), and two are stinkin’ mammals (and not the cool kind). I stand ready for your slings and arrows.
For previous posts on my drawings, see:
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
There has been an Aquilopsing – have you felt it?
April 22, 2017
One of the many nice things about getting to help name new taxa is that once you let them out into the world, other people can unleash their considerable talents on ‘your’ critters. Which means that every now and then, something cool pops up that you have a deep personal connection to. Things have been fairly quiet on the Aquilops front for a while, and all of a sudden I have news.
I’m still waiting for a plush Aquilops – c’mon, Homo sapiens, how has this not happened already? – but if you’d like a life-size Aquilops in bronze, sculptor James Herrmann has you covered. James got in touch with me last fall when the project was just in the planning stages. His timing was excellent – I’d just seen the presentation on camouflage in Psittacosaurus at SVPCA, and the paper by Vinther et al. was out a week or two later. I sent James some papers and photos of dead animals, he sent back photos of the work in progress, and now his Aquilops is done.
About the sculpture, James writes:
I am offering the sculpture for sale as a limited edition of 25. The sculpture is life sized, it is approximately 60 lbs and is 33″L x 14”H x 11”W. The price I am asking for it is $4500. I am getting a slab of green soapstone for the base although it does display well without the stone so it will be bolted on from below and not epoxied. […] The gingko leaves and log part of the sculpture were made from molds taken from plants growing locally.
I dig it. If you’re interested in getting one, please visit his website, HerrmannStudio.com.
Next item: back in 2014, Brian Engh created the public face of Aquilops with the wonderful graphic art he did for the paper and the press release. Now he’s gone back to the well and reimagined Aquilops, based in part on what we know of its paleoecology – that’s the image at the top of the post. He explains his new view of Aquilops in a thoughtful and wide-ranging video on his paleoart YouTube channel. (If you miss his rap videos set in the Daikaijucene, he also has a YouTube channel for music and monsters. And a blog. And a Patreon page. You get the picture.) You should also check out the two-part interview with Brian at the PLOS Paleo Community blog (part 1, part 2).
Here’s the aforementioned video:
Poster prints of Aquilops Classic and Next Gen can be purchased through Brian’s website, DontMessWithDinosaurs.com.
Finally, a couple of older Aquilops-themed art things that I didn’t cover when they happened. Lead author Andy Farke is also an award-winning homebrewer and he concocted his Eagle Face Oatmeal Stout in honor of our little buddy. He has lots more beer-and-dinosaur crossover goodness on his brewing blog – check it out.
Last fall artist Natalie Metzger did a bunch of drawings of extant animals wearing the skulls of extinct animals for Inktober. In the very first batch was this awesome squirrel looking unexpectedly badass in an Aquilops skull. I don’t know what it means, but I would totally play that D&D campaign. Natalie has a bunch more cool stuff on her blog and Patreon page, and she’ll be at the Rose City Comic Con in Portland this September, so go say hi and buy her art.
Really finally, I am not on Twitter – trust me, I don’t need less of a filter between my occasional stupidity and the world – but for all the rest of you, keep an eye on #Aquilops and, if you’re a heartless jerk, #Aquilopsburrito.
Have more Aquilops stuff I haven’t covered but should? The comment field is open.
References
- 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
- Vinther, J., Nicholls, R., Lautenschlager, S., Pittman, M., Kaye, T.G., Rayfield, E., Mayr, G., and Cuthill, I.C. 2016. 3D camouflage in an ornithischian dinosaur. Current Biology 26(18): 2456-2462.
A quick stop at the Oklahoma Museum of Natural History
December 21, 2016
I’m back in Oklahoma for the holidays, and anytime I’m near Norman I pop in to the OMNH to see old friends, both living and fossil. Here’s the Aquilops display in the hall of ancient life, which has been up for a while now. I got some pictures of it when I was here back in March, just never got around to posting them.
Aquilops close up. You can’t see it well in this pic, but on the upper right is a cast of the Aquilops cranium with a prosthesis that shows what the missing bits would have looked like. That prosthesis was sculpted by – who else? – Kyle Davies, the OMNH head preparator and general sculpting/molding/casting sorceror. You’ve seen his work on the baby apatosaur in this post. I have casts of everything shown here – original fossil, fossil-plus-prosthesis, and reconstructed 3D skull – and I should post on them. Something to do in the new year.
The Aquilops display is set just opposite the Antlers Formation exhibit, which has a family of Tenontosaurus being menaced by two Deinonychus, and at the transition between Early and Late Cretaceous. The one mount in the Late Cretaceous area is the big Pentaceratops, which is one of the best things in this or any museum.
Evidence in support of that assertion. Standing directly in front of this monster is a breathtaking experience, which I highly recommend to everyone.
It’s just perfect that you can see the smallest and earliest (at least for now) North American ceratopsian adjacent to one of the largest and latest. Evolution, baby!
I didn’t only look at dinosaurs – the life-size bronze mammoth in the south rotunda is always worth a visit, especially in holiday regalia.
No holiday post about the OMNH would be complete without a shot of “Santaposeidon” (previously seen here). I will never get tired of this!
The chances that I’ll get anything else posted in 2016 hover near zero, so I hope you all have a safe and happy holiday season and a wonderful New Year.
SV-POW! endorses Triceratops
May 6, 2016
Today, we were at the BYU Museum of Paleontology, which is in a ridiculously scenic setting with snow-capped mountains on the horizon in almost every direction.
We got through a lot of good work in collections, and we’ll show you some photos from there in due course. But for today, here are a couple of pictures from the public galleries.
First, here in a single photo is definitive proof that the “Toroceratops hypothesis” is wrong:
Say what you want about ontegenetic trajectories, that huge and well ossified Triceratops is not a juvenile of anything.
Good, glad we got that sorted out.
Meanwhile, at the even better end of the gallery, here is a very nice — and very well lit — cast of the famous articulated juvenile Camarasaurus specimen CM 11338 described by Gilmore (1925):
Further bulletins as events warrant.
References
Gilmore, Charles W. 1925. A nearly complete articulated skeleton of
Camarasaurus, a saurischian dinosaur from the Dinosaur National
Monument, Utah. Memoirs of the Carnegie Museum 10:347-384.
The world’s best Tenontosaurus skull
August 19, 2015

Left lateral skull schematic (above) and left skull photograph (below) of OMNH 58340. The skull is angled at the ‘alert position’ indicated by the horizontal semicircular canal. Natural fenestrae are shaded gray. Dashed outline denotes conjectural sclerotic ring. Anterior is to the left. Abbreviation: mf – maxillary foramen. Thomas (2015: fig. 2).
As stinkin’ ornithischians go, Tenontosaurus is near and dear to my heart. For some reason beyond the ken of mortals, the Antlers Formation of southeast Oklahoma has yielded only a small handful of Acrocanthosaurus (Stovall and Langston 1950; Currie and Carpenter 2000), one partial Deinonychus skeleton and a few dozen shed teeth (Brinkman et al. 1998), the single, lonely, woefully incomplete holotype specimen of Sauroposeidon (Wedel et al. 2000a, b) – and roughly five flarkjillion skeletons of Tenontosaurus. I know a lot of those skeletons intimately: between 1994 and 2001, I went on about two dozen OMNH digs to pull them out of the ground, and I worked on a couple as a volunteer preparator.

Anterior skull schematic (above) and photograph (below) of OMNH 58340. The two images are set to the same scale, demonstrating the amount of displacement in the right side of the skull. The schematic was reconstructed by digitally mirroring the left side of the rostrum and suspensorium in order to approximate the actual appearance of the skull. Natural fenestrae are shaded gray. Anterior is out of the page. Thomas (2015: fig. 18).
I was off to Berkeley in 2001, so I missed the fun when another crew got the best-ever Tonto specimen, OMNH 58340. Except for the back half of the tail, which had eroded away, almost every bit of the skeleton was preserved in perfect articulation, even the hyoid apparatus, terminal phalanges, proatlas, and atlas cervical ribs. The skull was a bit disarticulated – half of the rostrum had floated out of position, and the stapes and palpebrals were missing – but it’s still the nicest Tonto skull ever found, and one of the best-preserved fossils to ever come out of the Antlers Formation.
Now that skull has been very thoroughly described by Andrew Thomas. Andrew wrote it up for his MS thesis under my first mentor, Rich Cifelli, and it was published last month in Palaeontologica Electronica (Thomas 2015). I had dinner with Andrew and his family when I visited the OMNH in the spring of 2014, and he showed me a down-scaled translucent 3D print of the left half of OMNH 58340. I learned more about ornithischian skulls playing with that thing over dinner than I had in the previous two decades of (admittedly quarter-assed) study.

Medial view of the left side of the virtual skull of OMNH 58340 with the vomer present (10.1), allowing a view of the articulation of the vomer with the pterygoid, and with the palatine and vomer removed (10.2), allowing a view of the joints between the maxilla, lacrimal, prefrontal, jugal, ectopterygoid, and pterygoid. The vertically striated texture present on the visible surfaces of many elements, notably the lacrimal, maxilla, and premaxilla, is an artifact of the process used to isolate CT images of each element from the remainder of the data set. Abbreviations: f – flange; pp – posterior processes; tp – triangular processes. Thomas (2015: fig. 10).
So there’s me, playing with a down-scaled 3D print of a Tonto skull. Why am I telling you about this? Because if you want to print your own, you can – digital models of the complete cranium, and all of the individual elements, are available as STL files published along with the paper. Getting to the models takes some doing – they’re in a ZIP file linked from the paper’s Appendix 4, which you can access directly here.
Thomas (2015) has a lot more than just cool 3D models – there’s a lot of descriptive goodness, including the cranial endocast, cranial nerves, inner ear labyrinth, and hyoids; a whopping 62 figures, most in full color; and a phylogenetic analysis that incorporates the new morphological data on Tenontosaurus. No revelations there – despite all the nice specimens, Tonto remains an enigma from the murky realm between basal ornithopods and Iguanodontia. But if Oklahoma’s most abundant dinosaur is a bit of a phylogenetic mystery, it’s also becoming a paleobiologic gold mine, thanks in large part to the bone histology studies of Sarah Werning and colleagues (Lee and Werning 2008; Werning 2012 – also see Horner et al. 2009 on histology of Tenontosaurus from the Cloverly Formation of Montana). With the publication of this paper, Andrew Thomas is now part of the “Tenontaissance”. Congratulations, Andrew, and well done!
Now if we could just get some more Sauroposeidon…
References
- Brinkman, D. L.; Cifelli, R. L.; & Czaplewski , N. J. (1998). First occurrence of Deinonychus antirrhopus (Dinosauria: Theropoda) from the Antlers Formation (Lower Cretaceous: Aptian–Albian) of Oklahoma. Oklahoma Geological Survey Bulletin 146: 1–27.
- Currie, P. J., & Carpenter, K. (2000). A new specimen of Acrocanthosaurus atokensis (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA. Geodiversitas, 22(2), 207-246.
- Horner JR, de Ricqlès A, Padian K, Scheetz RD (2009) Comparative long bone histology and growth of the “hypsilophodontid” dinosaurs Orodromeus makelai, Dryosaurus altus, and Tenontosaurus tilletti (Ornithischia: Euornithopoda). Journal of Vertebrate Paleontology 29: 734–747.
- Lee, A. H., & Werning, S. (2008). Sexual maturity in growing dinosaurs does not fit reptilian growth models. Proceedings of the National Academy of Sciences, 105(2), 582-587.
- Stovall, J. W., & Langston, W. (1950). Acrocanthosaurus atokensis, a new genus and species of Lower Cretaceous Theropoda from Oklahoma. American Midland Naturalist, 43(3), 696-728.
- Thomas, D. Andrew. 2015. The cranial anatomy of Tenontosaurus tilletti Ostrom, 1970 (Dinosauria, Ornithopoda). Palaeontologia Electronica 18.2.37A: 1-99.
- Wedel, M.J., Cifelli, R.L., and Sanders, R.K. 2000a. Sauroposeidon proteles, a new sauropod from the Early Cretaceous of Oklahoma. Journal of Vertebrate Paleontology 20: 109-114.
- Wedel, M.J., Cifelli, R.L., and Sanders, R.K. 2000b. Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon. Acta Palaeontologica Polonica 45:343-388.
- Werning, S. (2012). The ontogenetic osteohistology of Tenontosaurus tilletti. PLoS ONE 7(3): e33539. doi:10.1371/journal.pone.0033539
Natural History Museum of Utah: wall of ceratopsians
July 8, 2015
Now that, faithful readers, is a monument to evolution and its endless forms most beautiful. I’m talking about the wall of ceratopsian skulls at NHMU, of course, not the back of Brian Engh’s head (bottom center).
If you don’t know them all on sight (yet!), here’s a cheat sheet. I goofed on a couple myself: before I looked at the sheet I figured Coahuilaceratops as Pentaceratops and mistook Kosmoceratops for Vagaceratops. Still, 12 out of 14 isn’t bad for a minor-league ceratopsian scholar such as yours truly.
Here’s the chasmosaurine-centric view from lower right.
And the centrosaurine-centric view from distant left.
The world needs more things like this. Good on ya, NHMU.
For other NHMU posts, see: