Here’s that ornithopod-skeleton anaglyph you ordered
November 26, 2022
While I was thinking about Diplodocus atlas ribs, I was reminded of the ribs on the atlas of a diplodocine skull-and-three-cervicals exhibit that Matt and I saw at MOAL(*) back in the heady days of the Sauropocalypse.
And that reminded me that I have other pairs of photos from the MOAL visit, which I took with the intention of making anaglyphs. like the one I did of the diplodocine. So here is an anaglyph of a small bipedal ornithischian whose exact identity I evidently didn’t bother to write down:
Does anyone know what this is? Maybe Dryosaurus or something along those lines?
(*) When Matt and I visited this museum, it was known as the North American Museum of Ancient Life, or NAMAL for short. Since then, it’s dropped the “North American” and promoted the “of”, and it’s now the Museum Of Ancient Life, or MOAL for short. But we’re sticking with the existing category (see link below) for continuity with other things we’ve posted from there.
Burpee PaleoFest 2020: my last conference
March 8, 2021
Last spring I was an invited speaker at PaleoFest at the Burpee Museum of Natural History in Rockford, Illinois. I meant to get these photos posted right after I got back. But I flew back from Illinois on Monday, March 9, 2020, and by the following weekend I was throwing together virtual anatomy labs for the med students. You know the rest.
The wall of ceratopsians at the Burpee Museum. Every museum should have one of these.
I had a fantastic time at PaleoFest. The hosts were awesome, the talks were great, the Burpee is a cool museum to explore, and the swag was phenomenal.
An ontogenetic series of Triceratops skulls. Check out how the bony horn cores switch from back-curving to forward-curving. The keratin sheaths over the horn cores elongated, but they didn’t remodel, so adult trikes probably had S-curving horns.
I know I poke a lot of fun at non-sauropods around here, but the truth is that I’m a pan-dino-geek at heart. When I’m looking at theropods and ceratopsians I am mostly uncontaminated by specialist knowledge or a desire to work on them, so I can relax, and squee the good squee.
I’m a sucker for dinosaur skin. It’s just mind-blowing that we can tell more or less what it would feel like to pet a dinosaur.
Among the memorable talks last year: Win McLaughlin educated me about rhinos, which are a heck of a lot weirder than I thought; Larisa DeSantis gave a mind-expanding talk about mammalian diets, evolution, and environmental change; and Holly Woodward explained in convincing detail why “Nanotyrannus” is a juvenile T. rex.
The pride of the Burpee Museum: Jane, the juvenile T. rex.
But my favorite presentation of the conference was Susie Maidment’s talk on stegosaurs. It was one of the those great talks in which the questions I had after seeing one slide were answered on the next slide, and where by end of the presentation I had absorbed a ton of new information almost effortlessly, by just listening to an enthusiastic person talk almost conversationally about their topic. And when I say “effortlessly”, I mean for the audience–I know from long experience that presentations like that are born from deep, thorough knowledge of one’s topic, deliberate planning, and rehearsal.
The big T. rex mount is pretty great, too.
That’s not to slight the other speakers, of course. All the talks were good, and that’s not an easy thing to pull off. Full credit to Josh Matthews and the organizing committee for putting on such an engaging and inspiring conference.
Did I say the swag was phenomenal? The swag was phenomenal. Above are just a few of my favorite things: a Burpee-plated Rite-in-the-Rain field notebook, a fridge magnet, a cool sticker, and at the center, My Precious: a personalized Estwing rock hammer. Estwing makes nice stuff, and a lot of paleontologists and field geologists carry Estwing rock hammers. Estwing is also based in Rockford, and they’ve partnered with the Burpee Museum to make these personalized rock hammers for PaleoFest, which is pretty darned awesome.
I already had an Estwing hammer–one of blue-grip models–which is good, because the engraved one is going in my office, not to the field. (If you’re wondering why my field hammer looks so suspiciously unworn, it’s because my original was stolen a few years ago, and I’m still breaking this one in. By doing stuff like this.)
There’s a little Burpee logo with a silhouette of Jane down at the end of the handle, so I had to take Jane to meet Jane.
Parting shot: I grew up in a house out in the country, about 2 miles outside of the tiny town of Hillsdale, Oklahoma, which is about 20 miles north of Enid, which is about 100 miles north-northwest of Oklahoma City. Hillsdale is less than an hour from Salt Plains National Wildlife Refuge, where you can go dig for selenite crystals like the ones shown above. The digging is only allowed in designated areas, to avoid unexploded ordnance from when the salt plains were used as a bombing range in World War II, and at certain times of year, to avoid bothering the endangered whooping cranes that nest there.
I don’t know how many times I went to Salt Plains to dig crystals as a kid, either on family outings or school field trips, but it was a lot. I still have a tub of them out in the garage (little ones, nothing like museum-quality). And there are nice samples, like the one shown above, in the mineral hall of just about every big natural history museum on the planet. One of my favorite things to do when I visit a new museum is go cruise the mineral display and find the selenite crystals from Salt Plains. I’ve seen Salt Plains selenite in London, Berlin, and Vienna, and in most of the US natural history museums that I’ve visited for research or for fun. The farm boy in me still gets a little thrill at seeing a little piece of northwest Oklahoma, from a place that I’ve been and dug, on display in far-flung cities.
I already credited Josh Matthews for organizing a fabulous conference, but I need to thank him for being such a gracious host. He helped me arrange transportation, saw that all my needs were met, kept me plied with food and drink, and drove me to Chicago, along with a bunch of other folks, for a Field Museum visit before my flight home, which is how I got this awesome photo, and also these awesome photos. Thanks also to my fellow speakers, for many fascinating conversations, and to the PaleoFest audience, for bringing their A game and asking good questions. I didn’t know that PaleoFest 2020 would be my last conference for a while, but it was certainly a good one to go out on.
Tutorial 38: little projects as footsteps toward understanding
January 11, 2021
This is a very belated follow-up to “Tutorial 12: How to find problems to work on“, and it’s about how to turn Step 2, “Learn lots of stuff”, into concrete progress. I’m putting it here, now, because I frequently get asked by students about how to get started in research, and I’ve been sending them the same advice for a while. As with Tutorial 25, from now on I can direct the curious to this post, and spend more time talking with them about what they’re interested in, and less time yakking about nuts and bolts. But I hope the rest of you find this useful, too.
Assuming, per Tutorial 12, that you’ve picked something to investigate–or maybe you’re trying to pick among things to investigate–what next? You need a tractable way to get started, to organize the things you’re learning, and to create a little structure for yourself. My recommendation: do a little project, with the emphasis on little. Anyone can do this, in any area of human activity. Maybe your project will be creating a sculpture, shooting and editing a video, learning–or creating–a piece of music, or fixing a lawn mower engine. My central interest is how much we still have to discover about the natural world, so from here on I’m going to be writing as a researcher addressing other researchers, or aspiring researchers.
Arteries of the anterior leg, from Gray’s Anatomy (1918: fig. 553). Freely available courtesy of Bartleby.com.
I’ll start with a couple of examples, both from my own not-too-distant history. A few years ago I got to help some of my colleagues from the College of Podiatric Medicine with a research project on the perforating branch of the peroneal artery (Penera et al. 2014). I knew that vessel from textbooks and atlases and from having dissected a few out, but I had never read any of the primary (journal) literature on it. As the designated anatomist on the project, I needed to write up the anatomical background. So I hit the journals, tracked down what looked like the most useful papers, and wrote a little 2-page summary. We didn’t use all of it in the paper, and we didn’t use it all in one piece. Some sentences went into the Introduction, others into the Discussion, and still others got dropped entirely or cut way down. But it was still a tremendously useful exercise, and in cases like this, it’s really nice to have more written down than you actually need. Here’s that little writeup, in case you want to see what it looks like:
Wedel 2013 anatomy of the perforating branch of the peroneal artery
Pigeon spinal cord cross-section, from Necker (2006: fig. 4).
More recently, when I started working with Jessie Atterholt on weird neural canal stuff in dinosaurs, I realized that I needed to know more about glycogen bodies in birds, and about bird spinal cords generally. I expected that to be quick and easy: read a couple of papers, jot down the important bits, boom, done. Then I learned about lumbosacral canals, lobes of Lachi, the ‘ventral eminences’ of the spinal cord in ostriches, and more, a whole gnarly mess of complex anatomy that was completely new to me. I spent about a week just grokking all the weird crap that birds have going on in their neural canals, and realized that I needed to crystallize my understanding while I had the whole structure in my head. Otherwise I’d come back in a few months and have to learn it all over again. Because it was inherently visual material, this time I made a slide deck rather than a block of text, something I could use to get my coauthors up to speed on all this weirdness, as well as a reminder for my future self. Here’s that original slide deck:
Wedel 2018 Avian lumbosacral spinal cord specializations
If you’re already active in research, you may be thinking, “Yeah, duh, of course you write stuff down as you get a handle on it. That’s just learning.” And I agree. But although this may seem basic, it isn’t necessarily obvious to people who are just starting out. And even to the established, it may not be obvious that doing little projects like this is a good model for making progress generally. Each one is a piton driven into the mountainside that I’m trying to climb: useful for me, and assuming I get them out into the world, useful for anyone I’d like to come with me (which, for an educator and a scientist, means everyone).
A view down the top of the vertebral column in the mounted skeleton of Apatosaurus louisae, CM 3018, showing the trough between the bifurcated neural spines.
If you’re not active in research, the idea of writing little term papers may sound like purgatory. But writing about something that you love, that fascinates you, is a very different proposition from writing about dead royalty or symbolism because you have to for a class.* I do these little projects for myself, to satisfy my curiosity, and it doesn’t feel like work. More like advanced play. When I’m really in the thick of learning a new thing–and not, say, hesitating on the edge before I plunge in–I am so happy that I tend to literally bounce around like a little kid, and the only thing that keeps me sitting still is the lure of learning the next thing. That I earn career beans for doing this still seems somewhat miraculous, like getting paid to eat ice cream.
* YMMV, history buffs and humanities folks. If dead royalty and symbolism rock your world but arteries and vertebrae leave you cold, follow your star, and may a thousand gardens grow.
Doing little projects is such a convenient and powerful way to make concrete progress that it has become my dominant mode. As with the piece that I wrote about the perforating branch of the peroneal artery, the products rarely get used wholesale in whatever conference presentation or research paper I end up putting together, but they’re never completely useless. First, there is the benefit to my understanding that I get from assembling them. Second, they’re useful for introducing other people to the sometimes-obscure stuff I work on, and nothing makes you really grapple with a problem like having to explain it to others. And third, these little writeups and slideshows become the Lego bricks from which I assemble future talks and papers. The bird neural canal slide deck became a decent chunk of our presentation on the Snowmass Haplocanthosaurus at the 1st Palaeontological Virtual Congress (Wedel et al. 2018)–and it’s about to become something even better. (Four months later: it did!)
The operative word at the start of the last paragraph is ‘concrete’. I don’t think this was always the case, but now that I’m in my mid-40s ‘what I know’ is basically equivalent to ‘what I remember’, which is basically equivalent to ‘what I’ve written down’. (And sometimes not even then–Mike and I both run across old posts here on SV-POW! that we’ve forgotten all about, which is a bit scary, given how often we put novel observations and ideas into blog posts.) Anyway, this is why I like the expression ‘crystallize my understanding’: the towers of comprehension that I build in my head are sand castles, and if I don’t find a way to freeze them in place, they will be washed away by time and my increasingly unreliable cerebral machinery.
Really nice Stegosaurus plate on display at Dinosaur National Monument.
Also, if I divide my life into the things I could do and the things I have done, only the things in the latter category are useful. So if you are wondering if it’s worthwhile to write a page to your future self about valves in the cerebral arteries of rats, or all of the dinosaurs from islands smaller than Great Britain, or whatever strange thing has captured your attention, I say yes, go for it. Don’t worry about finding something novel to say; at the early stages you’re just trying to educate yourself (also, talks and papers need intro and background material, so you can still get credit for your efforts). I’ll bet that if you set yourself the goal of creating a few of these–say, one per year, or one per semester–you’ll find ways to leverage them once you’ve created them. If all else fails, start a blog. That might sound flip, but I don’t mean for it to. I got my gig writing for Sky & Telescope because I’d been posting little observing projects for the readers of my stargazing blog.
A final benefit of doing these little projects: they’re fast and cheap, like NASA’s Discovery missions. So they’re a good way to dip your toes into a new area before you commit to something more involved. The more things you try, the more chances you have to discover whatever it is that’s going to make you feel buoyantly happy.
You may have noticed that all of my examples in this post involved library research. That’s because I’m particularly interested in using little projects to get started in new lines of inquiry, and whenever you are starting out in a new area, you have to learn where the cutting edge is before you can move it forward (Tutorial 12 again). Also, as a practical consideration, most of us are stuck with library research right now because of the pandemic. Obviously this library research is no substitute for time in the lab or the field, but even cutters and diggers need to do their homework, and these little projects are the best way that I’ve found of doing that.
P.S. If you are a student, read this and do likewise. And, heck, everyone else who writes should do that, too. It is by far the advice I give most often as a journal editor and student advisor.
P.P.S. As long as you’re reading Paul Graham, read this piece, too–this whole post was inspired by the bit near the end about doing projects.
References
- Gray, Henry. 1918. Anatomy of the Human Body. Lea & Febiger, Philadelphia. Bartleby.com, 2000. www.bartleby.com/107/.
- Penera, K., Manji, K., Wedel, M., Shofler, D., and Labovitz, J. 2014. Ankle syndesmotic fixation using two screws: Risk of injury to the Perforating Branch of the Peroneal Artery. The Journal of Foot and Ankle Surgery 53(5):534-8. DOI: 10.1053/j.jfas.2014.04.006
- Wedel, M.J., Atterholt, J., Macalino, J., Nalley, T., Wisser, G., and Yasmer, J. 2018. Reconstructing an unusual specimen of Haplocanthosaurus using a blend of physical and digital techniques. 1st Palaeontological Virtual Congress / PeerJ Preprints 6:e27431v1
The Day of the Dinosaur, and the legend of the regrown sauropod tail
October 17, 2019
Two professionals, hard at work.
After this year’s SVPCA, Vicki and London and I spent a few days with the Taylor family in the lovely village of Ruardean. It wasn’t all faffing about with the Iguanodon pelvis, the above photo notwithstanding. Mike and I had much to discuss after the conference, in particular what the next steps might be for the Supersaurus project. Mike has been tracking down early mentions of Supersaurus, and in particular trying to determine the point at which Jensen decided that it might be a diplodocid rather than a brachiosaurid. I recalled that Gerald Wood discussed Supersaurus in his wonderful 1982 book, The Guinness Book of Animal Facts and Feats. While on the track of Supersaurus, I stumbled across this amazing claim in the section on Diplodocus (Wood 1982: p. 209):
According to De Camp and De Camp (1968) these giant sauropods may have been able to regenerate lost parts, and they mention another skeleton collected in Wyoming which appeared to have lost about 25 per cent of its tail to a carnosaur and then regrown it — along with 21 new vertebrae!
De Camp and De Camp (1968) is a popular or non-technical book, The Day of the Dinosaur. Used copies can be had for a song, so I ordered one online and it was waiting for me when I got back to California.
The Day of the Dinosaur is an interesting book. L. Sprague De Camp and Catherine Crook De Camp embodied the concept of the “life-long learner” before there was a buzzword to go with it. He had been an aerospace engineer in World War II, and she had been an honors graduate and teacher, before they turned to writing full time. Individually and together, they produced a wide range of science fiction, fantasy, and nonfiction books over careers that spanned almost six decades. The De Camps’ writing in The Day of the Dinosaur is erudite in range but conversational in style, and they clearly kept up with current discoveries. They also recognized that science is a human enterprise and that, like any exploratory process, it is marked by wildly successful leaps, frustrating wheel-spinning, and complete dead ends. I was pleasantly surprised to find that the authors were completely up to speed on plate tectonics, an essentially brand-new science in 1968, and they explain it as an alternative to older theories about immensely long land bridges or sunken continents.
At the same time, the book arrived just before the end-of-the-1960s publications of John Ostrom and Bob Bakker that kicked off the Dinosaur Renaissance, so there’s no mention of warm-blooded dinosaurs. The De Camps’ sauropods and duckbills are still swamp-bound morons, “endlessly dredging up mouthfuls of soft plant food and living out their long, slow, placid, brainless lives” (p. 142), stalked by ‘carnosaurs’ that were nothing more than collections of teeth relentlessly driven by blind instinct and hunger. The book is therefore an artifact of a precise time; there was perhaps a year at most in the late 1960s when authors as technically savvy as the De Camps would have felt obliged to explain plate tectonics and its nearly-complete takeover of structural geology (which had just happened), but not to comment on the new and outrageous hypothesis of warm-blooded, active, terrestrial dinosaurs (which hadn’t happened yet).
The book may also appeal to folks with an interest in mid-century paleo-art, as the illustrations are a glorious hodge-podge of Charles R. Knight, Neave Parker, photos of models and mounted skeletons from museums, life restorations reproduced from the technical literature, and original art produced for the book, including quite a few line drawings by one L. Sprague De Camp. Roy Krenkel even contributed an original piece, shown above (if you don’t know Krenkel, he was a contemporary and sometime collaborator of Al Williamson and Frank Frazetta, and his art collection Swordsmen and Saurians is stunning and still gettable at not-completely-ruinous prices; I’ve had mine since about 1997).
ANYWAY, as entertaining as The Day of the Dinosaur is, it doesn’t do much to help us regenerate the tale of the regenerated tail. Here’s the entire story, from page 114:
Sauropods, some students think, had great powers of regenerating lost parts. One specimen from Wyoming is thought to have lost the last quarter of its tail and regrown it, along with twenty-one new tail vertebrae. That is better than a modern lizard can do; for the lizard, in regenerating its tail, grows only a stumpy approximation of the original, without new vertebrae.
That’s it. No sources mentioned or cited, so no advance over Wood in terms of tracking down the origin of the story.
Massospondylus tail with traumatic amputation at caudal 25 (Butler et al. 2013: fig. 1A).
To be clear, I don’t really think there is a sauropod that regrew its tail, especially since we have evidence for traumatic tail amputation without regeneration in the basal sauropodomorph Massospondylus (Butler et al. 2013), in the theropod Majungasaurus (Farke and O’Connor 2007), and in a hadrosaur (Tanke and Rothschild 2002). But I would love to learn how such a story got started, what the evidence was, how it was communicated, and most importantly, how it took on a life of its own.
If anyone knows any more about this, I’d be very grateful for any pointers. The comment thread is open.
References
- Butler, R. J., Yates, A. M., Rauhut, O. W., & Foth, C. 2013. A pathological tail in a basal sauropodomorph dinosaur from South Africa: evidence of traumatic amputation? Journal of Vertebrate Paleontology 33(1): 224-228.
- De Camp, L. S., and De Camp, C. C. 1968. The Day of the Dinosaur. Bonanza Books, New York, 319 pp.
- Farke, A. A., & O’Connor, P. M. 2007. Pathology in Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology, 27(S2): 180-184.
- Krenkel, R. G. 1989. Swordsmen and Saurians: From the Mesozoic to Barsoom. Eclipse Books, 152 pp.
- Tanke, D. H., & Rothschild, B. M. 2002. DINOSORES: An annotated bibliography of dinosaur paleopathology and related topics—1838-2001. Bulletin of the New Mexico Museum of Natural History and Science, vol. 20.
- Wood, G. L. 1982. The Guinness Book of Animals Facts & Feats (3rd edition). Guinness Superlatives Ltd., Enfield, Middlesex, 252 pp.
Parasaurolophus sculpture by Brian Engh
October 7, 2019
This past summer I did a post on my birthday card from Brian Engh, but I haven’t posted about my birthday present from him: this handmade fired-clay sculpture of Parasaurolophus.
I don’t have a ton to say about it, other than that — as you can tell from the photos — it looks pretty darned convincing. I adore the fern leaf impressions in the base.
This sits on the mantle in our living room. My eye wanders to it in stray moments. I’ve often run down ornithopods as boring, but they’re all right. They’re the clade of dinosaurs most remote from my research, so they’re about the only ones left that just signify “dinosaur” to me, without any research-related intellectual baggage. So when I’m woolgathering and my eyes land on this sculpture, it doesn’t make me think about me or now. It makes me think about them, and then. It’s a talismanic time machine. And a pretty darned great birthday present. Thanks, Brian!
Matt bought an Iguanodon pelvis … OR DID HE???!
September 16, 2019
We’re just back from an excellent SVPCA on the Isle of Wight. We’ll write more about it, but this time I just want to draw attention to a neat find. During a bit of down time, Matt and Vicki were wandering around West Cowes (the town where the scientific sessions were held), when they stumbled across a place called That Shop. Intrigued by all the Lego figures in the window, they went in, and Matt found a small section of fossils. Including … an Iguanodon pelvis, supposedly certified as such by the Dinosaur Isle museum.
Here it is: I imagine that whoever classified it read this elongate concave surface as part of the acetabulum. Matt’s hypothesis is that they mistook it for a sacral vertebra and that became “pelvis” via over-simplification.
It’s about 18 cm in a straight line across the widest part, or 20 cm around the curve.
Here is an actual documentary record of Matt’s moment of discovery:
Yep, you got it! It’s a sauropod vertebra! (Matt would never have spent good money on a stinkin’ appendicular element of a stinkin’ ornithopod.)
Specifically, it’s the bottom half of the front part of the centrum of a dorsal vertebra:
“Eucamerotus” dorsal vertebra NHMUK PV R88 in right lateral and anterior views. Non-faded portions show the location of the Wedel Specimen. Modified from Hulke (1880: plate IV).
In these photos, we’re looking down into it more or less directly dorsal view, with anterior to the left. Click through the photos, and — once you know what you’re looking at — you can clearly see the pneumatic spaces: nice patches of finished bone lining the camellae, with trabecular bone in between.
Clearly there’s nowhere near enough of this to say what it is with any certainty. But our best guess is that it seems compatible with a titanosauriform identity, quite possibly in same space as the various Wealden sauropod dorsals that have been assigned to Ornithopsis or Eucamerotus.
References
- Hulke, J. W. 1880. Supplementary Note on the Vertebræ of Ornithopsis, Seeley, = Eucamerotous, Hulke. Quarterly Journal of the Geological Society 36:31–35. doi:10.1144/GSL.JGS.1880.036.01-04.06
James Herrmann’s Aquilops bust
June 21, 2019
You may recall that sculptor James Herrmann did a life-size bronze of Aquilops (shown above) back in 2017. I love it, and I’d get one in a heartbeat if I had the disposable income or the space in which to display it. Since I have neither, I got in touch with James and asked if he’d be interested in doing a casting of just the bust. Happily for me, he was game, and today this sturdy wooden crate arrived in the mail:
Inside, insanely well-packed in lots of cushy foam:
That’s a t-shirt James threw in with my order. But you’re probably more interested in this, which was also in the crate:
Unpacked and plunked on the crate lid on the lawn since it was the best I could come up with on short notice:
Some nicer photos by James of the same sculpture in prettier surroundings:
The bust is mounted on a gorgeous piece of polished green marble, with thick felt on the bottom so it won’t scratch up the furniture. The max length of the base is 9.5 inches and when standing on a desk or table, the whole piece is almost exactly 12 inches tall. I haven’t weighed it but it’s heavy enough that you could knock someone out with it, no problem.
I’d say it looks nice, but that’s both redundant, in this photo-heavy post, and a gross understatement. It looks absurdly nice, like it wandered into my space from some other, classier joint. I have some serious desk-cleaning to do so it won’t look like I stole this.
Instead of doing a big run of these, James is having them cast one at a time, on demand. The cost is $500 plus shipping; mine came to $573.33 shipped. If you want one, or want to browse James’s catalogue, or commission something yourself, you can find him at http://www.herrmannstudio.com/.
Thanks, James, for your interest in ‘my’ critter, for your skill in bringing it to life, and for making this bust available. I love it.
Did dinosaurs have a second brain to run their back ends?
January 18, 2019
In short, no. I discussed this a bit in the first post of the Clash of the Dinosaurs saga, but it deserves a more thorough unpacking, so we can put this dumb idea to bed once and for all.
As Marco brought up in the comments on the previous post, glycogen bodies are probably to blame for the idea that some dinosaurs had a second brain to run their back ends. The glycogen body is broadly speaking an expansion of the spinal cord, even though it is made up of glial cells rather than neurons — simply put, help-and-support cells, not sensory, motor, or integration cells. When the spinal cord is expanded, the neural canal is expanded to accommodate it; as usual, the nervous system comes first and the skeleton forms around it. This creates a cavity in the sacrum that is detectable in fossils.
Giffin (1991) reviewed all of the evidence surrounding endosacral enlargements in dinosaurs (primarily sauropods and stegosaurs) and concluded that the explanation that best fit the observations was a glycogen body like that of birds. I agree 100%. The endosacral cavities of sauropods and stegosaurs (1) expand dorsally, instead of in some other direction, and (2) expand and contract over just a handful of vertebrae, instead of being more spread out. Of the many weird specializations of the spinal cord in birds, the glycogen body is the only one that produces that specific signal.
If any part of the nervous system of birds and other dinosaurs might be described as a ‘second brain’, it wouldn’t be the glycogen body, it would be the lumbosacral expansion of the spinal cord, which really is made up of neurons that help run the hindlimbs and tail (more on that in this previous post). But there’s nothing special about that, it’s present in all four-limbed vertebrates, including ourselves. Interestingly, that bulk of extra neural tissue in the sacral region of birds was referred to as a sort of ‘second brain’ by Streeter way back in 1904, in reference to the ostrich, but it’s clear that he meant that as an analogy, not that it’s literally a second brain.
Borrowed from http://humanorgans.org/spinal-cord/
So to sum up, a gradual expansion of the spinal cord to help run the hindlimbs and tail IS present in dinosaurs — and birds, and cows, and frogs, and us. But if that qualifies as a ‘second brain’, then we also have a ‘third brain’ farther up the spinal cord to run our forelimbs: the cervical enlargement, as shown in the above figure. These spinal expansions aren’t actual brains by any stretch and referring to them as such is confusing and counterproductive.
The sharp expansion of the neural canal over just a few vertebrae in birds does not house a ‘second brain’ or even an expansion of the neural tissue of the spinal cord. It contains the glycogen body, which is not made of neurons and has no brain-like activity. The sacral cavities of non-avian dinosaurs replicate precisely the qualities associated with the glycogen bodies of birds, and there’s no reason to expect that they contained anything else. That we don’t know yet what glycogen bodies do, even in commercially important species like chickens, may make that an unsatisfying answer, but it’s what we have for now.
The next installment will be way weirder (edit: it was, and is!). Stay tuned!
References
- Giffin, E.B.,1991. Endosacral enlargements in dinosaurs. Modern Geology 16: 101-112.
- Streeter, G.L. 1904. The structure of the spinal cord of the ostrich. American J. Anatomy 3(1): 1-27.
Aquilops skull, take 3
December 12, 2018
Nothing really new here, not like a new skull recon or anything. The original version I did for Farke et al. (2014) had the jaw articulated and closed. Then in 2017 I posted a version with the lower jaw disarticulated. Obviously what was needed was one with the lower jaw articulated and open. Now it exists, here. I mean, since I posted the separate parts last year people have had everything they needed to make their own, but it’s nice to have one already built, so here you go.
My good friend, frequent collaborator, and fellow adventurer Brian Engh has won the John J. Lanzendorf Paleoart Prize for 2D paleoart (there are also categories for 3D paleoart and scientific illustration). He’s in august company; previous Lanzendorf winners include luminaries like John Gurche, Michael Skrepnick, Mark Hallett, Todd Marshall, and Julius Csotonyi (among many others–see the complete list of previous winners here). Naturally I’m happy as heck for Brian, and immensely proud of him, not only for the award, but also for what he’s doing now. Usually when we say “pay it forward” we mean metaphorically, but Brian is literally going to pay it forward. He’s created his own paleoart contest, the SummonENGH 2018, and he will award half of his October Patreon take to the winner.
He lays out the rules on his blog and in this video:
There’s a Facebook group, here, and a hashtag: #TheSummonEngh2018 (Facebook, Twitter).
Why do I think this is cool? It’s no exaggeration to say that I am a paleontologist today because I was exposed to mind-bending paleoart from a young age. Brian cares about paleoart–he cares about making better paleoart, himself, and he cares about making paleoart better, for everyone. And now he’s putting his money where his mouth his and doing something to hopefully bring more visibility to the paleoart community, and help move the field forward. That’s admirable, and I’m happy to support the cause.
Also, when we visited the Aquilops display at Dinosaur Journey this summer, we were lucky enough to capture this single frame showing a 100% real paleo-energy discharge. I definitely felt something at the time, but I didn’t know the full extent of what had happened until Brian sorted through our photos after the trip. Apparently this was all fated to happen–some kind of transdimensional chronoparticle emission linking past and future–and who am I to argue with fate?
Now, go summon monsters!
Sauropod Vertebra Picture of the Week 
