As John himsef admits in the tweet that announced this picture, it’s five years late … but I am prepared to forgive that because IT’S NEVER TOO LATE TO BRONTOSMASH!

As always, John’s art is not just scientifically accurate, but evocative. Here’s a close-up of the main action area:

As you see, he has incorporated the keratinous neck spikes that we hypothesized, based on the distinct knobs that are found at the ventrolateral ends of apatosaurine cervical rib loops.

John has also incorporated a lot of blood — which is exactly what you get when elephant seals collide:

By the way, if John’s BRONTOSMASH! art can be said to be five years late — so can the actual paper. It was of course at SVPCA 2015 that we first presented our apatosaur-neck-combat hypothesis (Taylor et al. 2015), and it’s not at all to our credit that nearly five years later, we have not even got a manuscript written. We really need to get our act together on this project, so consider this post my apology on behalf of myself, Matt, Darren and Brian.

Reference

  • Taylor, Michael P., Mathew J. Wedel, Darren Naish and Brian Engh. 2015. Were the necks of Apatosaurus and Brontosaurus adapted for combat?. p. 71 in Mark Young (ed.), Abstracts, 63rd Symposium for Vertebrate Palaeontology and Comparative Anatomy, Southampton. 115 pp. doi:10.7287/peerj.preprints.1347v1

Our old sparring partner Cary Woodruff is a big fan of Monarobot, a Mexican artist who does all of her pieces in a Maya artistic style. So he commissioned this piece:

Anyone can tell that this is an apatosaurine cervical in anterior view — but which apatosaurine cervical? SV-POW Dollars(*) await the first person to correctly identify it.

Cary points out that one neat thing about the art is the colours: where possible, Monarobot uses colors the Mayas used. That blue in the vertebra is a special plant-based pigment they created.

As things stand, Cary owns the world’s only copy of this piece. But he points out that it’s born-digital, so anyone else who wants a copy is at liberty to order one; and he’s gracious enough not to object to the dilution of his print’s uniqueness. I don’t think there is a way to order directly online, but you can contact Monarobot in various places:

 


(*) Street value of SV-POW Dollars: zero.

 

In the last post, we looked at some sauropod vertebrae exposed in cross-section at our field sites in the Salt Wash member of the Morrison Formation. This time, we’re going to do it again! Let’s look at another of my faves from the field, with Thuat Tran’s hand for scale. And, er, a scale bar for scale:

And let’s pull the interesting bits out of the background:

Now, confession time. When I first saw this specimen, I interpeted it as-is, right-side up. The round thing in the middle with the honeycomb of internal spaces is obviously the condyle of a vertebra, and the bits sticking out above and below on the sides frame a cervical rib loop. I figured the rounded bit at the upper right was the ramus of bone heading for the prezyg, curved over as I’ve seen it in some taxa, including the YPM Barosaurus. And the two bits below the centrum would then be the cervical ribs. And with such big cervical rib loops and massive, low-hanging cervical ribs, it had to an apatosaurine, either Apatosaurus or Brontosaurus.

Then I got my own personal Cope-getting-Elasmosaurus-backwards moment, courtesy of my friend and fellow field adventurer, Brian Engh, who proposed this:

Gotta say, this makes a lot more sense. For one, the cervical ribs would be lateral to the prezygs, just as in, oh, pretty much all sauropods. And the oddly flat inward-tilted surfaces on what are now the more dorsal bones makes sense: they’re either prezyg facets, or the flat parts of the rami right behind the prezyg facets. The missing thing on what is now the right even makes sense: it’s the other cervical rib, still buried in a projecting bit of sandstone. That made no sense with the vert the other way ’round, because prezygs always stick out farther in front than do the cervical ribs. And we know that we’re looking at the vert from the front, otherwise the backwards-projecting cervical rib would be sticking through that lump of sandstone, coming out of the plane of the photo toward us.

Here’s what I now think is going on:

I’m still convinced that the bits of bone on what is now the left side of the image are framing a cervical rib loop. And as we discussed in the last post, the only Morrison sauropods with such widely-set cervical ribs are Camarasaurus and the apatosaurines. So what makes this an apatosaurine rather than a camarasaur? I find several persuasive clues:

  • If we have this thing the right way up, those prezygs are waaay up above the condyle, at a proportional distance I’ve only seen in diplodocids. See, for example, this famous cervical from CM 3018, the holotype of A. louisae (link).
  • The complexity of the pneumatic honeycombing inside the condyle is a much better fit for an apatosaurine than for Camarasaurus–I’ve never seen that level of complexity in a camarasaur vert.
  • The bump on what we’re now interpreting as the cervical rib looks suspiciously like one of the ventrolateral processes that Kent Sanders and I identified in apatosaurine cervicals back in our 2002 paper. I’ve never seen them, or seen them reported, in Camarasaurus–and I’ve been looking.
  • Crucially, the zygs are not set very far forward of the cervical ribs. By some rare chance, this is pretty darned close to a pure transverse cut, and the prezygs, condyle (at its posterior extent, anyway), and the one visible cervical rib are all in roughly the same plane. In Camarasaurus, the zygs strongly overhang the front end of the centrum in the cervicals (see this and this).

But wait–aren’t the cervical ribs awfully high for this to be an apatosaurine? We-ell, not necessarily. This isn’t a very big vert; max centrum width here is 175mm, only about a third the diameter of a mid-cervical from something like CM 3018. So possibly this is from the front of the neck, around the C3 or C4 position, where the cervical ribs are wide but not yet very deep. You can see something similar in this C2-C5 series on display at BYU:

Or, maybe it’s just one of the weird apatosaurine verts that has cervical rib loops that are wide, but not very deep. Check out this lumpen atrocity at Dinosaur Journey–and more importantly, the apatosaur cervical he’s freaking out over:

UPDATE just a few minutes later: Mike reminded me in the comments about the Tokyo apatosaurine, NSMT-PV 20375, which has wide-but-not-deep cervical ribs. In fact, C7 (the vertebra on the right in this figure) is a pretty good match for the Salt Wash specimen:

UpchurchEtAl2005-apatosaurus-plate2-C3-6-7

NSMT-PV 20375, cervical vertebrae 3, 6 and 7 in anterior and posterior views. Modified from Upchurch et al. (2005: plate 2).

UPDATE the 2nd: After looking at it for a few minutes, I decided that C7 of the Tokyo apatosaurine was such a good match for the Salt Wash specimen that I wanted to know what it would look like if it was similarly sectioned by erosion. In the Salt Wash specimen, the prezygs are sticking out a little farther than the condyle and cervical rib sections. The red line in this figure is my best attempt at mimicking that erosional surface on the Tokyo C7, and the black outlines on the right are my best guess as to what would be exposed by such a cut (or pair of cuts). I’ve never seen NSMT-PV 20375 in person, so this is just an estimate, but I don’t think it can be too inaccurate, and it is a pretty good match for the Salt Wash specimen.

Another way to put it: if this is an apatosaurine, everything fits. Even the wide-but-not-low-hanging cervical ribs are reasonable in light of some other apatosaurines. If we think this is Camarasaurus just because the cervical ribs aren’t low-hanging, then the pneumatic complexity, the height of the prezygs, and the ventrolateral process on the cervical rib are all anomalous. The balance of the evidence says that this is an apatosaurine, either a small, anterior vert from a big one, or possibly something farther back from a small one. And that’s pretty satisfying.

One more thing: can we take a moment to stand in awe of this freaking thumb-sized cobble that presumably got inside the vertebra through one its pneumatic foramina and rattled around until it got up inside the condyle? Where, I’ll note, the internal structure looks pretty intact despite being filled with just, like, gravel. As someone who spends an inordinate amount of time thinking about how pneumatic vertebrae get buried and fossilized, I am blown away by this. Gaze upon its majesty, people!

This is another “Road to Jurassic Reimagined, Part 2″ post. As before, Part 1 is here, Part 2 will be going up here in the near future. As always, stay tuned.

References

Nature’s CT machine

January 28, 2020

Because I’ve worked a lot on the anatomy and evolution of air-filled bones in sauropod dinosaurs, I’ve spent most of my career looking at images like this:

CT sections through a cervical vertebra of an apatosaurine (Apatosaurus or Brontosaurus), OMNH 1094. Wedel (2003b: fig. 6). Scale bar is 10cm.

…and thinking about images like this:

Physical sections through pneumatic vertebrae of Giraffatitan. Janensch (1950: figs. 71-73).

Turns out, that’s pretty good practice for fossil prospecting in the Salt Wash member of the Morrison Formation, where we frequently find things like this:

That’s a bit hard to read, so let’s pull it out from the background:

This is almost certainly a pneumatic vertebra of a sauropod, sectioned more-or-less randomly by the forces of erosion to expose a complicated honeycomb of internal struts and chambers. The chambers are full of sandstone now, but in life they were full of air. I say “almost certainly” because there is small chance that it could belong to a very large theropod, but it looks more sauropod-y to me (for reasons I may expand upon in the comments if anyone is curious).

I’m not 100% certain what section this is. At first I was tempted to read it as a transversely-sectioned dorsal, something like the Allosaurus dorsal shown in this post (link) but from a small, possibly juvenile sauropod. But the semi-radial, spoke-like arrangement of the internal struts going to the round section at the bottom looks very much like the inside of the condyle of a sauropod cervical or cervico-dorsal–compare to fig. 71 from Janensch (1950), shown above. And of course there is no reason to suspect that the plane of this cut is neatly in any of the cardinal anatomical directions. It is most likely an oblique cut that isn’t purely transverse or sagittal or anything else, but some combination of the above. It’s also not alone–there are bits and bobs of bone to the side and above in the same chunk of sandstone, which might be parts of this vertebra or of neighboring bones. Assuming it is a sauropod, my guess is Diplodocus or Brachiosaurus, because it looks even more complex than the sectioned cervicals and dorsals I’ve seen of Haplocanthosaurus, Camarasaurus, or the apatosaurines.

Sometimes we can do a little better. This is one of my favorite finds from the Salt Wash. This boulder, now in two parts, fell down out of a big overhanging sandstone cliff. When the boulder hit, it broke into two halves, and the downhill half rolled over 180 degrees, bringing both cut faces into view in this photo. And there in the boulder is what looks like two vertebrae, but is in fact the neatly separated halves of a single vertebra. I know I refer to erosion and breakage as “Nature’s CT machine”, but this time that’s really on the nose. Let’s take a closer look:

Here’s what I see:

It’s a proportionally long vertebra with a round ball at one end and a hemispherical socket at the other end: a cervical vertebra of a sauropod. Part of the cervical rib is preserved on the upper side, which I suspect is the left side. The parapophysis on the opposite side is angled a bit out of the rock, toward the camera. Parapophyses of sauropod cervicals tend to be angled downward, and if we’re looking at the bottom of this vertebra, then the rib on the upper side is the left. The right cervical rib was cut off when the boulder broke. All we have on this side are the wide parapophysis and the slender strut of the diapophysis aiming out of the rock toward the missing rib, which must still be embedded in the other half of the boulder–and in fact you can see a bit of it peeking out in the counterpart in the wide shot, above.

Can we get a taxonomic ID? I think so, based on the following clues:

  • The cervical ribs are set waaay out to either side of the centrum, by about one centrum diameter. Such wide-set cervical ribs occur in Camarasaurus and the apatosaurines, Apatosaurus and Brontosaurus, but not typically in Diplodocus, Brachiosaurus, or other Morrison sauropods.
  • The cervical rib we can see the most of is pretty slender, like those of Camarasaurus, in contrast to the massive, blocky cervical ribs of the apatosaurines (for example).
  • We can see at least bits of both the left and right cervical ribs in the two slabs–along with a section right through the centrum. So the cervical ribs were set wide from the centrum but not displaced deeply below it, as in Camarasaurus, and again in contrast to the apatosaurines, in which the cervical ribs are typically displaced far below (ventral to) the centrum (see this).
  • This one is a little more loosey-goosey, but the exposed internal structure looks “about right” for Camarasaurus. There is a mix of large and small chambers, but not many small ones, and nothing approaching the coarse, regular honeycomb we’d expect in Apatosaurus, Brontosaurus, or Diplodocus, let alone the fine irregular honeycomb we’d expect in Barosaurus or Brachiosaurus (although I will show you a vert like that in an upcoming post). On the other hand, the internal structure is too complex for Haplocanthosaurus (compare to the top image here).
  • As long as Camarasaurus is on the table, I’ll note that the overall proportions are good for a mid-cervical of Cam as well. That’s not worth much, since vertebral proportions vary along the column and almost every Morrison sauropod has cervicals with this general proportion somewhere in the neck, but it doesn’t hurt.

So the balance of the evidence points toward Camarasaurus. In one character or another, every other known Morrison sauropod is disqualified.

When it’s too dark to hunt for sauropods, you can look at other things.

Now, Camarasaurus is not only the most common sauropod in the Morrison, it’s also the most common dinosaur of any kind in the formation. So this isn’t a mind-blowing discovery. Still, it’s nice to be able to get down to a genus-level ID based on a single vertebra fortuitously sectioned by Mother Nature. In upcoming posts, I’ll show some of the more exciting critters that we’ve been able to ID out of the Salt Wash, ‘we’ here including Brian Engh, John Foster, ReBecca Hunt-Foster, Jessie Atterholt, and Thuat Tran. Brian will also be showing many of these same fossils in the next installment of Jurassic Reimagined. Catch Part 1 here (link), and stay tuned to Brian’s paleoart channel (here) for more in the very near future.

References

The Man Himself, taking notes on what look like Giraffatitan caudals.

Here’s how I got my start in research. Through a mentorship program, I started volunteering at the Oklahoma Museum of Natural History in the spring of 1992, when I was a junior in high school. I’d been dinosaur-obsessed from the age of three, but I’d never had an anatomy course and didn’t really know what I was doing. Which is natural! I had no way of knowing what I was doing because I lacked training. Fortunately for me, Rich Cifelli took me under his wing and showed me the ropes. I started going out on digs, learned the basics of curatorial work, how to mold and cast fossils, how to screenwash matrix and then pick microfossils out of the concentrate under a dissecting microscope, and—perhaps most importantly—how to make a rough ID of an unidentified bone by going through the comparative element collection until I found the closest match.

All set, right? Ignition, liftoff, straight path from there to here, my destiny unrolling before me like a red carpet.

No.

It could have gone that way, but it didn’t. I had no discipline. I was a high-achieving high school student, but it was all to satisfy my parents. When I got to college, I didn’t have them around to push me anymore, and I’d never learned to push myself. I went off the rails pretty quickly. Never quite managed to lose my scholarships, without which I could not have afforded to be in college, period, but I skimmed just above the threshold of disaster and racked up a slate of mediocre grades in courses from calculus to chemistry. I even managed to earn a C in comparative anatomy, a fact which I am now so good at blocking out that I can go years at a time without consciously recalling it.

After three years of this, I had the most important conversation of my life. Because I was a zoology major I’d been assigned a random Zoology Dept. faculty member as an undergrad advisor. I was given to Trish Schwagmeyer, not because we got on well (we did, but that was beside the point) or had similar scientific interests, just luck of the draw. And it was lucky for me, because in the spring of 1996 Trish looked at my grades from the previous semester, looked me in the eye, and said, “You’re blowing it.” She then spent the next five minutes explaining in honest and excruciating detail just how badly I was wrecking my future prospects. I’ve told this story before, in this post, but it bears repeating, because that short, direct, brutal-but-effective intervention became the fulcrum for my entire intellectual life and future career.

The holotype specimen of Sauroposeidon coming out of the ground in 1994.

Roughly an hour later I had the second most important conversation of my life, with Rich Cifelli. While I’d been lost in the wilderness my museum volunteering had petered out to zero, and Rich would have been completely justified in telling me to get lost. Not only did he not do that, he welcomed me back into the fold, in a terrifyingly precise recapitulation of the Biblical parable of the prodigal son. When I asked Rich if I could do an independent study with him in the next semester, he thought for a minute and said, “Well, we have these big dinosaur vertebrae from the Antlers Formation that need to be identified.” Which is how, at the age of 21, with a rubble pile of an academic transcript and no real accomplishments to stand on, I got assigned to work on OMNH 53062, the future holotype of Sauroposeidon proteles.

I was fortunate in four important ways beyond the forgiveness, patience, and generosity of Richard Lawrence Cifelli:

  • OMNH 53062 was woefully incomplete, just three and a half middle cervical vertebrae, which meant that the project was small enough in concept to be tractable as an independent study for an undergrad. Rich and I both figured that I’d work on the vertebrae for one semester, come up with a family-level identification, and maybe we’d write a two-pager for Oklahoma Geology Notes documenting the first occurrence of Brachiosauridae (or whatever it might turn out to be) in the vertebrate fauna of the Antlers Formation.
  • Because the specimen was so incomplete, no-one suspected that it might be a new taxon, otherwise there’s no way such an important project would have been assigned to an undergrad with a spotty-to-nonexistent track record.
  • Despite the incompleteness, because the specimen consisted of sauropod vertebrae, it held enough characters to be identifiable–and eventually, diagnosable. Neither of those facts were known to me at the time.
  • All of Rich’s graduate students were already busy with their own projects, and nobody else was about to blow months of time and effort on what looked like an unpromising specimen.

NB: this guy is not a prodigy.

There is a risk here, in that I come off looking like some kind of kid genius for grasping the importance of OMNH 53062, and Rich’s other students look like fools for not seeing it themselves. It ain’t like that. The whole point is that nobody grasped the importance of the specimen back then. It would take Rich and me a whole semester of concentrated study just to come to the realization that OMNH 53062 might be distinct enough to be diagnosable as a new taxon, and a further three years of descriptive and comparative work to turn that ‘maybe’ into a paper. People with established research programs can’t afford to shut down everything else and invest six months of study into every incomplete, garbage-looking specimen that comes down the pike, on the off chance that it might be something new. Having the good judgment to not pour your time down a rat-hole is a prerequisite for being a productive researcher. But coming up with a tentative ID of an incomplete, garbage-looking specimen is a pretty good goal for a student project: the student learns some basic comparative anatomy and research skills, the specimen gets identified, no existing projects get derailed, and no-one established wastes their time on what is most likely nothing special. If the specimen does turn out to be important, that’s gravy.

So there’s me at the start of the fall of 1996: with a specimen to identify and juuuust enough museum experience, from my high school mentorship, to not be completely useless. I knew that one identified a fossil by comparing it to known things and looking for characters in common, but I didn’t know anything about sauropods or their vertebrae. Rich got me started with a few things from his academic library, I found a lot more in OU’s geology library, and what I couldn’t find on campus I could usually get through interlibrary loan. I spent a lot of time that fall standing at a photocopier, making copies of the classic sauropod monographs by Osborn, Hatcher, Gilmore, Janensch, and others, assembling the raw material to teach myself sauropod anatomy.

The sauropod monographs live within arm’s reach of my office chair to this day.

In addition to studying sauropods, I also started going to class, religiously, and my grades rose accordingly. At first I was only keeping up with my courses so that I would be allowed to continue doing research; research was the carrot that compelled me to become a better student. There was nothing immediate or miraculous about my recovery, and Rich would have to give me a few well-deserved figurative ass-kickings over the next few years when I’d occasionally wander off course again. But the point was that I had a course. After a few months I learned—or remembered—to take pride in my coursework. I realized that I had never stopped defining myself in part by my performance, and that when I’d been adrift academically I’d also been depressed. It felt like crawling out of a hole.

(Aside: I realize that for many people, depression is the cause of academic difficulty, not the reverse, and that no amount of “just working harder” can offset the genuine biochemical imbalances that underlie clinical depression. I sympathize, and I wish we lived in a world where everyone could get the evaluation and care that they need without fear, stigma, crushing financial penalties, or all of the above. I’m also not describing any case here other than my own.)

What fresh hell is this? (Apatosaur dorsal from Gilmore 1936)

Out of one hole, into another. The biggest problem I faced back then is that if you are unfamiliar with sauropod vertebrae they can be forbiddingly complex. The papers I was struggling through referred to a pandemonium of laminae, an ascending catalog of horrors that ran from horizontal laminae and prespinal laminae through infraprezygapophyseal laminae and spinopostzygapophyseal laminae. Often these features were not labeled in the plates and figures, the authors had just assumed that any idiot would know what a postcentrodiapophyseal lamina was because, duh, it’s right there in the name. But that was the whole problem: I didn’t know how to decode the names. I had no map. SV-POW! tutorials didn’t exist. Jeff Wilson’s excellent and still-eminently-useful 1999 paper codifying the terminology for sauropod vertebral laminae was still years in the future.

Then I found this, on page 35 of Werner Janensch’s 1950 monograph on the vertebrae of what was then called Brachiosaurus brancai (now Giraffatitan):

It was in German, but it was a map! I redrew it by hand in my very first research notebook, and as I was copying down the names of the features the lightbulb switched on over my head. “Diapophyse” meant “diapophysis”, and it was the more dorsal of the two rib attachments. “Präzygapophyse” was “prezygapophysis”, and it was one of the paired articular bits sticking out the front of the neural arch. And, crucially, “Präzygodiapophysealleiste” had to be the prezygodiapophyseal lamina, which connected the two. And so on, for all of the weird bits that make up a sauropod vertebra.

It’s been 22 years and I still remember that moment of discovery, my pencil flying across the page as I made my own English translations of the German anatomical terms, my mind buzzing with the realization that I was now on the other side. Initiated. Empowered. I felt like I had pulled the sword from the stone, found Archimedes’ lever that could move the world. In the following weeks I’d go back through all of my photocopied sauropod monographs with my notebook open to the side, reading the descriptions of the vertebrae for the second or third times but understanding them for the first time, drawing the vertebrae over and over again until I could call up their basic outlines from memory. This process spilled over from the fall of 1996 into the spring of 1997, as Rich and I realized that OMNH 53062 would require more than one semester of investigation.

Interlude with a left femur of the Oklahoma apatosaurine (but not the largest individual).

My memories of those early days of my sauropod research are strongly shaped by the places and circumstances in which I was doing the work. Vicki and I had gotten married in the summer of 1996 and moved into a two-bedroom duplex apartment on the north side of Norman. The upstairs had a long, narrow bathroom with two sinks which opened at either end onto the two upstairs bedrooms, the one in which we slept and the one we used as a home office. In the mornings I could get showered and dressed in no time, and while Vicki was getting ready for work or school I’d go into the office to read sauropod papers and take notes. Vicki has always preferred to have music on while she completes her morning rituals, so I listened to a lot of Top 40 hits floating in from the other upstairs rooms while I puzzled out the fine details of sauropod vertebral anatomy.

Two songs in particular could always be counted on to play in any given hour of pop radio in the early spring of 1997: Wannabe by the Spice Girls, and Lovefool by the Cardigans. I am surely the only human in history to have this particular Pavlovian reaction, but to this day when I hear either song I am transported back to that little bedroom office where I spent many a morning poring over sauropod monographs, with my working space illuminated by the light of the morning sun pouring through the window, and my mind illuminated by Werner Janensch, who had the foresight and good grace to give his readers a map.

Figure 5 from my undergraduate thesis: OMNH 53062 in right lateral view.

If you want to know what I thought about OMNH 53062 back in 1997, you can read my undergraduate thesis—it’s a free download here. Looking back now, the most surprising thing to me about that thesis is how few mentions there are of pneumaticity. I met Brooks Britt in the summer of 1997 and had another epochal conversation, in which he suggested that I CT scan OMNH 53062 to look at the air spaces inside the vertebrae. I filed my undergrad thesis in December of 1997, and the first session CT scanning OMNH 53062 took place in January, 1998. So in late 1997 I was still a pneumaticity n00b, with no idea of the voyage I was about to embark upon.

In 2010, after I was settled in as an anatomist at Western University of Health Sciences, I wrote a long thank-you to Trish Schwagmeyer. It had been 14 years since that pivotal conversation, but when she wrote back to wish me well, she still remembered that I’d gotten a C in comparative anatomy. I’d have a chance to make amends for that glaringly anomalous grade later the same year. At ICVM in Punta del Este, Uruguay, I caught up with Edie Marsh-Matthews, who had taught my comparative anatomy course back when. I apologized for having squandered the opportunity to learn from her, and she graciously (and to my relief) shifted the conversation to actual comparative anatomy, the common thread that connected us in the past and the present.

If the story has a moral, it’s that I owe my career in large part to people who went out of their way to help me when I was floundering. And, perhaps, that the gentle approach is not always the best one. I needed to have my head thumped a few times, verbally, to get my ass in gear, when less confrontational tactics had failed. I slid easily through the classrooms of dozens of professors who watched me get subpar grades and didn’t try to stop me (counterpoint: professors are too overworked to invest in every academic disaster that comes through the door, just like paleontologists can’t study every garbage specimen). If Trish Schwagmeyer and Rich Cifelli had not decided that I was worth salvaging, and if they not had the grit to call me out on my BS, I wouldn’t be here. As an educator myself now, that thought haunts me. I hope that I will be perceptive enough to know when a student is struggling not because of a lack of ability but through a lack of application, wise enough to know when to deploy the “you’re blowing it” speech, and strong enough to follow through.

References

  • Gilmore Charles W. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300 and plates XXI–XXXIV.
  • Janensch, Werner.  1950.  Die Wirbelsaule von Brachiosaurus brancai.  Palaeontographica (Suppl. 7) 3: 27-93.
  • Wedel, M.J. 1997. A new sauropod from the Early Cretaceous of Oklahoma. Undergraduate honor thesis, Department of Zoology, University of Oklahoma, Norman, OK. 43pp.
  • Wilson, J.A. 1999. A nomenclature for vertebral laminae in sauropods and other saurischian dinosaurs. Journal of Vertebrate Paleontology 19: 639-653.

Matt with big Apato dorsal 2000

Final bonus image so when I post this to Facebook, it won’t grab the next image in line and crop it horribly to make a preview. This is me with OMNH 1670, in 2003 or 2004, photo by Andrew Lee.

A life-size silhouette of the Snowmass Haplocanthosaurus, with Thierra Nalley, me, and Jessie Atterholt for scale. Photo by Jeremiah Scott.

Tiny Titan, a temporary exhibit about the Snowmass Haplocanthosaurus project, opened at the Western Science Center in Hemet, California, last night. How? Why? Read on.

Things have been quieter this year on the Haplo front than they were in 2018, for many reasons. My attention was pulled away by a lot of teaching and other day-job work–we’re launching a new curriculum at the med school, and that’s eaten an immense amount of time–and by some very exciting news from the field that I can’t tell you about quite yet (but watch this space). Things are still moving, and there will be a paper redescribing MWC 8028 and all the weird and cool things we’ve learned about it, but there are a few more timely things ahead of it in the queue.

One of the things going on behind the scenes this year is that Jessie Atterholt, Thierra Nalley, and I have been working with Alton Dooley, the director of the Western Science Center, on this exhibit. Alton has had a gleam in his eye for a long time of using the WSC’s temporary exhibit space to promote the work of local scientists, and we had the honor of being his first example. He also was not fazed by the fact that the project isn’t done–he wants to show the public the process of science in all of its serendipitous and non-linear glory, and not just the polished results that get communicated at the end.

Everything’s better cut in half. Photo by Jessie Atterholt.

Which is not to say that the exhibit isn’t polished. On the contrary, it looks phenomenal. Thanks to a loan from Julia McHugh at Dinosaur Journey in Colorado, most of the real fossils are on display. We’re only missing the ribs and most of the sacrum, which is too fragmentary and fragile to come out of its jacket. As you can see from the photo up top, there is a life-size vinyl silhouette of the Snowmass Haplo, with 3D prints of the vertebrae in approximate life position. Other 3D prints show the vertebrae before and after the process of sculpting, rescanning, and retrodeformation, as described in our presentation for the 1st Palaeontological Virtual Congress last year (that slideshow is a PeerJ Preprint, here). The exhibit also includes panels on “What is Haplocanthosaurus” and its relationships, on pneumaticity in sauropods, on the process of CT scanning and 3D modeling, and on the unusual anatomical features of the Snowmass specimen. The awesome display shown above, with the possibly-bumpy spinal cord and giant intervertebral discs reconstructed, was all Alton–he did the modeling, printing, and assembly himself.

Haplo vs Bronto. Thierra usually works on the evolution and development of the vertebral column in primates, so I had to show her how awesome vertebrae can be when they’re done right. Photo by Brittney Stoneburg.

My favorite thing in the exhibit is this striking comparison of one the Snowmass Haplo caudals with a proximal caudal from the big Oklahoma apatosaurine. This was Alton’s idea. He asked me if I had any photos of caudal vertebrae from really big sauropods that we could print at life size to compare to MWC 8028, and my mind went immediately to OMNH 1331, which is probably the second-largest-diameter vertebra of anything from all of North America (see the list here). It was also Alton’s idea to fill in the missing bits using one of Marsh’s plates of Brontosaurus excelsus from Como Bluff in Wyoming. It’s a pretty amazing display, and it turns out to have been a vehicle for discovery, too–I didn’t realize until I saw the verts side-by-side that the neural canal of the Snowmass Haplo caudal is almost as big as the neural canal from the giant apatosaurine caudal. It’s not a perfect comparison, because the OMNH fossil doesn’t preserve the neural canal, and the Como specimen isn’t that big, but proportionally, the Snowmass Haplo seems to have big honkin’ neural canals, not just at the midpoint (which we already knew), but all the way through. Looks like I have some measuring and comparing to do.

(Oh, about the title: we don’t know if the Snowmass Haplo was fully grown or not, but not all haplocanthosaurs were small. The mounted H. delfsi in Cleveland is huge, getting into Apatosaurus and Diplodocus territory. Everything we can assess in the Snowmass Haplo is fused, for what that’s worth. We have some rib chunks and Jessie will be doing histo on them to see if we can get ontogenetic information. I’ll keep you posted.)

Brian’s new Haplocanthosaurus restoration, along with some stinkin’ mammals. Photo by Jessie Atterholt.

Brian Engh contributed a fantastic life restoration of Haplocanthosaurus pro bono, thanks to this conversation, which took place in John Foster’s and ReBecca Hunt-Foster’s dining room about a month ago:

Brian: What are you drawing?

Me: Haplocanthosaurus.

Brian: Is that for the exhibit?

Me: Yup.

Brian (intense): Dude, I will draw you a Haplocanthosaurus.

Me: I know, but you’re a pro, and pros get paid, and we didn’t include a budget for paleoart.

Brian (fired up): I’m offended that you didn’t just ask me to draw you a Haplocanthosaurus.

Then he went to the Fosters’ couch, sat down with his sketchbook, and drew a Haplocanthosaurus. Not only is it a stunning piece on display in the exhibit, there are black-and-white printouts for kids to take and color (or for adults to take to their favorite tattoo artists, just sayin’). [Obligatory: this is not how things are supposed to work. We should all support original paleoart by supporting the artists who create it. But Brian just makes so damn many monsters that occasionally he has to kick one out for the heck of it. Also, I support him on Patreon, and you can, too, so at a stretch you could consider this the mother of all backer rewards.]

One special perk from the opening last night: Jessica Bramson was able to attend. Who’s that, you ask? Jessica’s son, Mike Gordon, found the first piece of bone from the Snowmass Haplo on their property in Colorado over a decade ago. Jessica and her family spent two years uncovering the fossils and trying to get paleontologists interested. In time she got in touch with John Foster, and the rest is history. Jessica lives in California now, and thanks to John’s efforts we were able to invite her to the exhibit opening to see her dinosaur meet the world. Stupidly, I did not get any photos with her, but I did thank her profusely.

A restored, retrodeformed caudal of the Snowmass Haplocanthosaurus, 3D-printed at life size for the exhibit. Photo swiped from the WSC Facebook page.

I owe a huge thanks to Alton Dooley for taking an interest in our work, and to the whole WSC crew for their hard work creating and promoting the exhibit. You all rock.

The exhibit will run through the end of March, 2020, at least. I deliberately did not show most of it, partly because I was too busy having fun last night to be diligent about taking photos, but mostly because I want you to go see it for yourself (I will do a retrospective post with more info after the exhibit comes down, for people who weren’t able to see it in person). If you make it out to Hemet, I hope you have half as much fun going through the exhibit as we did making it.

Way back in 2009–over a decade ago, now!–I blogged about the above photo, which I stole from this post by ReBecca Hunt-Foster. It’s a cut and polished chunk of a pneumatic sauropod vertebra in the collections at Dinosaur Journey in Fruita, Colorado.

This is the other side of that same cut; you’ll see that it looks like a mirror image of the cut at the top, but not quite a perfect mirror image, because some material was lost to the kerf of the saw and to subsequent polishing, and the bony septa changed a bit just in those few millimeters.

And this is the reverse face of the section shown above. As you can see, it is a LOT more complex. What’s going on here? This unpolished face must be getting close to either the condyle or the cotyle, where the simple I-beam or anchor-shaped configuration of the centrum breaks up into lots of smaller chambers (as described in this even older post). It’s crazy how fast that can happen–this shard of excellence is only about 4 or 5 cm thick, and in that short space it has gone from anchor to honeycomb. I think that’s amazing, and beautiful.

It’s probably Apatosaurus–way too complex to be Camarasaurus or Haplocanthosaurus, not complex enough to be Barosaurus, no reason to suspect Brachiosaurus, and although there is other stuff in the DJ collections, the vast majority of the sauropod material is Apatosaurus. So that’s my null hypothesis for the ID.

Oh, back in 2009 I was pretty sure these chunks were from a dorsal, because of the round ventral profile of the centrum. I’m no longer so certain, now that I know that the anchor-shaped sections are so close to the end of the centrum, because almost all vertebrae get round near the ends. That said, the anchor-shaped sections are anchor-shaped because the pneumatic foramina are open, and having foramina that open, that close to the end of the vertebra still makes me think it is more likely a dorsal than anything else. I’m just less certain than I used to be–and that has been the common theme in my personal development over the last decade.

 

I had an interesting opportunity when I was in Utah and Colorado a couple of weeks ago. At Dinosaur Journey in Fruita, Colorado, I went looking for a cast of the Potter Creek Brachiosaurus humerus. I found it — more on that another time — and I also found a cast of BYU 4503, the holotype dorsal vertebra of Dystylosaurus (now almost universally regarded as Supersaurus [but then…]), lurking with it in a corner of the collections room.

Dystylosaurus cast, posterior view.

Somehow I had overlooked the Dystylosaurus cast on all of my previous visits to DJ, which is a shame, because the cast is easy to pick up, flip over, and manipulate. Very much unlike the actual fossil, which combines the charming attributes, shared with many other sauropod vertebrae, of weighing hundreds of pounds but still being awfully fragile.

Dystylosaurus cast, anterior view.

So, hey ya, I had a chance to photograph and measure both sides of the vertebra. You’re not supposed to take measurements from casts, but I figured what the heck, no-one was going to lock me up for it, and I could compare the measurements from the cast to the measurements of the real thing when I visited BYU later in the trip. And that’s exactly what I did. It was easy to make sure I took the second set of measurements the same way I had done the first set, because I took them just a few days apart.

The real deal at BYU.

Here’s what I got. For each measurement, the actual value measured from the real fossil at BYU comes first, followed by the same measurement from the cast at Dinosaur Journey, followed by the difference as a percentage of the first (true) measurement.

  • Total Height (as preserved): 1050mm / 1022mm / -2.6%
  • Max Width (as preserved): 905mm / 889mm / -1.8%
  • Anterior Centrum Height: 400mm / 394mm / -1.5%
  • Anterior Centrum Width: 470mm / 454mm / -3.4%
  • Posterior Centrum Height: 365mm / 352mm / -3.5%
  • Posterior Centrum Width: 480mm / 473mm / -1.5%

They’re not the same! On average, the measurements of the cast are 2.4% smaller than the same measurements taken from the actual bone. (Incidentally, you may be wondering how I measured the posterior centrum faces of the BYU vertebra without flipping it. I used a couple of wooden blocks as orthogonators and measured between them, and I did it at several points to make sure they were truly parallel. In essence, I made giant redneck calipers, a method that Mike and I have had to employ many times when measuring huge, weirdly-shaped fossils. Remind me to show you John Foster’s giant caliper setup sometime.)

Dinosaur Journey cast in right lateral view, big doofus for scale.

Anyway, the discrepancy in the measurements should not be surprising. It is a known phenomenon that when an object is molded and cast, there is a little bit of shrinkage. You can see it bedevil Adam Savage in his quest for the ultimate Maltese Falcon replica in this charming video:

So, on one hand, no outright disasters here; all of the cast measurements are within a few percent of the real measurements, so if all you had was a cast, you could get a pretty good sense of the size of the real thing. But precision counts, even among giant sauropods. In a world where the largest vertebra of Argentinosaurus is only 1cm bigger in diameter than the largest vertebra of Patagotitan, differences like I got with Dystylosaurus would be enough to scramble the order of giant vertebrae. So if you’re ever stuck measuring something from a cast, be forthright and say as much, so that no-one mistakes the cast measurements for the real thing.

Here are some more measurements from BYU 4503, the real thing, for you completists. Note that the vertebra is sheared a bit from right postero-ventral to left antero-dorsal, so figuring out how to take the centrum length is not straightforward. I ended up doing it twice, once orthogonal to the posterior centrum face, and once following the slant of the centrum, both at the mid-height of the centrum, as shown in the little diagram from my notebook (above).

  • Centrum Length, left side, orthogonal: 295mm
  • Centrum Length, left side, on the slant: 310mm
  • Centrum Length, right side, orthogonal: 280mm
  • Centrum Length, right side, on the slant: 305mm
  • Max Width across prezygs: 305mm
  • Min gap between prezygs: 19mm
  • Max Width across parapophyses: 620mm
  • Max antero-posterior length of prezyg articular surfaces: 55mm
  • Max antero-posterior depth of hypantrum: 95mm
  • Max antero-posterior depth of fossa between spino-prezyg laminae (SPRLs): 80mm
  • Neural spine cavity, max antero-posterior extent: 40mm
  • Neural spine cavity, max medio-lateral extent: 70mm

Finally, a huge thanks to Julia McHugh at Dinosaur Journey and Brooks Britt and Rod Scheetz at BYU for letting me come play with their huge toys er, hugely important scientific specimens. Rod was particularly helpful, shifting giant things about with a forklift, helping me measure bones that are longer than I am tall, and boxing up loan specimens for me. Mike and I have had really good luck with pro-science curators and collections managers, but the folks at DJ and BYU have always been standouts, and I can’t thank them enough.

Back into the Corner of Shame, artificially tiny Dystylosaurus!

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.

My talk (Taylor and Wedel 2019) from this year’s SVPCA is up!

The talks were not recorded live (at least, if they were, it’s a closely guarded secret). But while it was fresh in my mind, I did a screencast of my own, and posted it on YouTube (CC By). I had to learn how to do this for my 1PVC presentation on vertebral orientation, and it’s surprisingly straightforward on a Mac, so I’ve struck while the iron is hot.

For the conference, I spoke very quickly and omitted some details to squeeze the talk into a 20-minute slot. In this version, I go a bit slower and make some effort to ensure it’s intelligible to an intelligent layman. That’s why it runs closer to half an hour. I hope you’ll find it worth your time.

References