Here are some blank diagrams I whipped up for drawing in spinal cord pathways.

This one shows the whole cord, brainstem, thalamus, and cerebral cortex in coronal section, in cartoon form.

It’s for drawing in ascending sensory and descending motor pathways, as shown in this office hours sketch. DC-ML is dorsal column/medial lemniscus, which carries discriminative touch and conscious proprioception. ALS is anterolateral system, which carries pain, temperature, pressure, and itch. The lateral corticospinal tract carries fibers for voluntary control of major muscle groups. Each pathway differs in terms of where it decussates (crosses the midline, left-to-right and vice versa) and synapses (relays from one neuron to the next). The sensory pathways involve primary, secondary, and tertiary sensory neurons, and the motor pathways involve upper motor neurons (UMNs) and lower motor neurons (LMNs).

This one shows cross-sections of the cord at cervical, thoracic, lumbar, and sacral levels, for drawing ascending and descending pathways and thinking about how patterns of somatotopy come to exist.

Somatotopy is the physical representation of the body in the central nervous system. A common abbreviation scheme is A-T-L for arm-trunk-leg, as shown here for ascending sensory and descending motor pathways.

Finally, this one shows the spinal cord and spinal nerve roots at four adjacent spinal levels, for tracking the specific fates of sensory and motor neurons at each spinal level.

This is particularly useful when working out the consequences of an injury, like the spinal cord hemisection (Brown-Sequard syndrome) shown here in pink. The little human figure only shows the zone in which pain and temperature sensation are lost. There would also be losses of discriminative touch, conscious proprioception, and voluntary motor control on the same side as the injury.

Finally, since we’ve had a bit of a sauropod drought lately, here are a couple of photos of the mounted cast skeleton of Patagotitan in Stanley Field Hall at the Field Museum of Natural History in Chicago.

I gotta say, this mount beats the one at the AMNH in every way, because it’s well lit and you can move all the way around it and even look down on it from above. In fact, in terms of getting to move all the way around it, get well back from it to see the whole thing at once, and even walk directly underneath it (without having to ask permission to hop the fence), it might be the best-mounted sauropod skeleton in the world. The Brachiosaurus outside is also pretty great (evidence), but it loses points because you can’t walk around it on an upstairs balcony. Every other mounted sauropod I know of is either in more cramped surroundings, or you can’t get underneath it, or is less well-lit, or some combination of the above. Am I forgetting any worthy contenders? Feel free to make your case in the comments.

Incidentally, the spinal cord of Patagotitan was something like 120 feet long, and the longest DC-ML primary sensory neurons ran all the way from tail-tip to brainstem before they synapsed, making them among the longest cells in the history of life.

A belated thank-you to Josh Matthews and the rest of the Burpee PaleoFest crew for a fun day at the FMNH back in March. I got home from that trip about 3 days before the pandemic quarantine started, so it’s waaaaay past time for me to blog about how awesome that trip was. Watch this space.

Long before Matt and others were CT-scanning sauropod vertebrae to understand their internal structure, Werner Janensch was doing it the old-fashioned way. I’ve been going through old photos that I took at the Museum für Naturkunde Berlin back in 2005, and I stumbled across this dorsal centrum:

Dorsal vertebra centum of ?Giraffatitan in ventral view, with anterior to top.

You can see a transverse crack running across it, and sure enough the front and back are actually broken apart. Here there are:

The same dorsal vertebral centrum of ?Giraffatitan, bisected transversely in two halves. Left: anterior half in posterior view; right: posterior half in anterior view. I had to balance the anterior half on my shoe to keep it oriented corrrectly for the photo.

This does a beautiful job of showing the large lateral foramina penetrating into the body of the centrum and ramifying further into the bone, leaving only a thin midline septum.

But students of the classics will recognise this bone immediately as the one that Janensch (1947:abb. 2) illustrated the posterior half of in his big pneumaticity paper:

It’s a very strange feeling, when browsing in a collection, to come across a vertebra that you know from the literature. As I’ve remarked to Matt, it’s a bit like running into, say, Cameron Diaz in the corner shop.


  • Janensch, W. 1947. Pneumatizitat bei Wirbeln von Sauropoden
    und anderen Saurischien. Palaeontographica, supplement

Storm Giant

March 12, 2020

Challenge: can you spot the Iguanodon pelvis in this photo?

Big news: I will be at the Burpee Museum PaleoFest this year. I’m speaking at 10:30 AM on Sunday, March 8. The title of my talk is, “In the Footsteps of Giants: Finding and Excavating New Fossils of Brachiosaurus from the Lower Morrison Formation in Utah”. Brian Engh, John Foster, and ReBecca Hunt-Foster are all coauthors.

The main page for PaleoFest 2020 is here (link), and on the right side of that page there’s a block of quick links to the speaker list, daily schedules, and so on. If you’re in the Midwest and not already booked for the weekend of March 7-8, come on out and I’ll talk your legs off about dinosaurs.

The photo above is of me at a table at the Raymond M. Alf Museum Fossil Fest on February 8, 2020. It’s nothing to do with the Burpee PaleoFest, I just needed a photo of me talkin’ Brachiosaurus. And yes, you can have that t-shirt — objectively the greatest in the history of the universe — when you cut it off my cold, dead carcass. (Or you can order your own; this model is the “Retro Brontosaurus Dinosaur T-shirt” by Dinosaur Tees and the Amazon link is here.)

No, not his new Brachiosaurus humerus — his photograph of the Chicago Brachiosaurus mount, which he cut out and cleaned up seven years ago:

This image has been on quite a journey. Since Matt published this cleaned-up photo, and furnished it under the Creative Commons Attribution (CC By) licence, it has been adopted as the lead image of Wikipedia’s Brachiosaurus page [archvied]:

Consequently (I assume) it has now become Google’s top hit for brachiosaurus skeleton:

Last Saturday, Fiona and I went to Birdland, a birds-only zoo in the Cotswolds, about an hour away from where we live. The admission price also includes “Jurassic Journey”, a walking tour of a dozen or so not-very-good dinosaur models. In an interpretive centre in this area, I found this Brachiosaurus skeletal reconstruction stencilled on the wall:

I immediately knew it was the Chicago mount due to the combination of Giraffatitan anterior dorsals and Brachiosaurus posterior dorsals; but I found it more hauntingly familiar than that. A quick hunt turned up Matt’s seven-year-old post, and when I told Matt about my discovery he filled me in on its use in Wikipedia.

So this is 99% of a good story: we’re delighted that this work is out there, and has resulted in a much better Brachiosaurus image at Birdland than the rather sad-looking Stegosaurus next to it. The only slight disappointment is that I couldn’t find any sign of credit, which they really should have included given that Matt put the image out under CC By rather than in the public domain.

But as Matt said: “Even though I didn’t get credited, I’m always chuffed to see my stuff out in the world.” So true.


FHPR 17108, a right humerus of Brachiosaurus, with Wes Bartlett and his Clydesdale Molly for scale. Original paleoart by Brian Engh.

Last May I was out in the Salt Wash member of the Morrison Formation with Brian Engh and Thuat Tran, for just a couple of days of prospecting. We’d had crappy weather, with rain and lots of gnats. But temperatures were cooler than usual, and we were able to push farther south in our field area than ever before. We found a small canyon that had bone coming out all over, and as I was logging another specimen in my field book, I heard Brian shout from a few meters away: “Hey Matt, I think you better get over here! If this is what I think it is…”

What Brian had found–and what I couldn’t yet show you when I put up this teaser post last month–was this:

That’s the proximal end of a Brachiosaurus humerus in the foreground, pretty much as it was when Brian found it. Thuat Tran is carefully uncovering the distal end, some distance in the background.

Here’s another view, just a few minutes later:

After uncovering both ends and confirming that the proximal end was thin, therefore a humerus (because of its shape), and therefore a brachiosaur (because of its shape and size together), we were elated, but also concerned. This humerus–one of the largest ever found–was lying in what looked like loose dirt, actually sitting in a little fan of sediment cascading down into the gulch. We knew we needed to get it out before the winter rains came and destroyed it. And for that, we’d need John Foster’s experience with getting big jackets out of inconvenient places. We were also working out there under the auspices of John’s permit, so for many reasons we needed him to see this thing.

We managed to all rendezvous at the site in June: Brian, John, ReBecca Hunt-Foster, their kids Ruby and Harrison, and Thuat. We uncovered the whole bone from stem to stern and put on a coat of glue to conserve it. Any doubts we might have had about the ID were dispelled: it was a right humerus of Brachiosaurus.

While we were waiting for the glue to dry, Brian and Ruby started brushing of a hand-sized bit of bone showing just a few feet away. After about an hour, they had extracted the chunk of bone shown above. This proved to be something particularly exciting: the proximal end of the matching left humerus. We hiked that chunk out, along with more chunks of bone that were tumbled down the wash, which may be pieces of the shaft of the second humerus.

But we still had the intact humerus to deal with. We covered it with a tarp, dirt, and rocks, and started scheming in earnest on when, and more importantly how, to get it out. It weighed hundreds of pounds, and it was halfway down the steep slope of the canyon, a long way over broken ground from even the unmaintained jeep trail that was the closest road. Oh, and there are endangered plants in the area, so we coulnd’t just bulldoze a path to the canyon. We’d have to be more creative.

I told a few close friends about our find over the summer, and my standard line was that it was a very good problem to have, but it was actually still a problem, and one which we needed to solve before the winter rains came.

As it happened, we didn’t get back out to the site until mid-October, which was pushing it a bit. The days were short, and it was cold, but we had sunny weather, and we managed to get the intact humerus uncovered and top-jacketed. Here John Foster and ReBecca Hunt-Foster are working on a tunnel under the bone, to pass strips of plastered canvas through and strengthen the jacket. Tom Howells, a volunteer from the Utah Field House in Vernal, stands over the jacket and assists. Yara Haridy was also heavily involved with the excavation and jacketing, and Brian mixed most of the plaster himself.

John Foster, Brian Engh, Wes and Thayne Bartlett, and Matt Wedel (kneeling). Casey Cordes (blue cap) is in the foreground, working the winch. Photo courtesy of Brian Engh.

Here we go for the flip. The cable and winch were rigged by Brian’s friend, Casey Cordes, who had joined us from California with his girlfriend, teacher and photographer Mallerie Niemann.

Photo courtesy of Brian Engh.

Jacket-flipping is always a fraught process, but this one went smooth as silk. As we started working down the matrix to slim the jacket, we uncovered a few patches of bone, and they were all in great shape.

So how’d we get this monster out of the field?

From left to right: Wes Bartlett and one of his horses, Matt Wedel, Tom Howells, and Thayne Bartlett. Photo by Brian Engh.

Clydesdales! John had hired the Bartlett family of Naples, Utah–Wes, Resha, and their kids Thayne, Jayleigh, Kaler, and Cobin–who joined us with their horses Molly and Darla. Brian had purchased a wagon with pneumatic tires from Gorilla Carts. Casey took the point on winching the jacket down to the bottom of the wash, where we wrestled it onto the wagon. From there, one of the Clydesdales took it farther down the canyon, to a point where the canyon wall was shallow enough that we could get the wagon up the slope and out. The canyon slope was slickrock, not safe for the horses to pull a load over, so we had to do that stretch with winches and human power, mostly Brian, Tom, and Thayne pushing, me steering, and Casey on the winch.

Easily the most epic and inspiring photo of my butt ever taken. Wes handles horses, Casey coils rope, Thayne pushes the cart, and Kaler looks on. Photo by Brian Engh.

Up top, Wes hooked up the other horse to pull the wagon to the jeep trail, and then both horses to haul the jacket out to the road on a sled. I missed that part–I had gone back to the quarry to grab tools before it got dark–but Brian got the whole thing on video, and it will be coming soon as part of his Jurassic Reimagined documentary series.

There’s one more bit I have to tell, but I have no photos of it: getting the jacket off the sled and onto the trailer that John had brought from the Field House. We tried winching, prybar, you name it. The thing. Just. Did. Not. Want. To. Move. Then Yara, who is originally from Egypt, said, “You know, when my people were building the pyramids, we used round sticks under the big blocks.” As luck would have it, I’d brought about a meter-long chunk of thick dowel from my scrap wood bin. Brian used a big knife to cut down some square posts into roughly-round shapes, and with those rollers, the winch, and the prybar, we finally got the jacket onto the trailer.

The real heroes of the story are Molly and Darla. In general, anything that the horses could help with went waaay faster and more smoothly than we expected, and anything we couldn’t use the horses for was difficult, complex, and terrifying. I’d been around horses before, but I’d never been up close and personal with Clydesdales, and it was awesome. As someone who spends most of his time thinking about big critters, it was deeply satisfying to use two very large animals to pull out a piece of a truly titanic animal.

Back in the prep lab at the Field House in Vernal: Matt Wedel, Brian Engh, Yara Haridy, ReBecca Hunt-Foster, and John Foster.

We’re telling the story now because the humerus is being unveiled for the public today at the Utah Field House of Natural History State Park Museum in Vernal. The event will be at 11:00 AM Mountain Time, and it is open to the public. The humerus, now cataloged as FHPR 17108, will be visible to museum visitors for the rest of its time in the prep lab, before it eventually goes on display at the Field House. We’re also hoping to use the intact right humerus as a Rosetta Stone to interpet and piece back together the shattered chunks of the matching left humerus. There will be a paper along in due time, but obviously some parts of the description will have to wait until the right humerus is fully prepped, and we’ve made whatever progress we can reconstructing the left one.

Why is this find exciting? For a few reasons. Despite its iconic status, in dinosaur books and movies like Jurassic Park, Brachiosaurus is actually a pretty rare sauropod, and as this short video by Brian Engh shows, much of the skeleton is unknown (for an earlier, static image that shows this, see Mike’s 2009 paper on Brachiosaurus and Giraffatitan, here). Camarasaurus is known from over 200 individuals, Apatosaurus and Diplodocus from over 100 individuals apiece, but Brachiosaurus is only known from about 10. So any new specimens are important.

A member of the Riggs field crew in 1900, lying next to the humerus of the holotype specimen of Brachiosaurus. I’m proud to say that I know what this feels like now!

If Brachiosaurus is rare, Brachiosaurus humeri are exceptionally rare. Only two have ever been described. The first one, above, is part of the holotype skeleton of Brachiosaurus, FMNH P25107, which came out of the ground near Fruita, Colorado, in 1900, and was described by Elmer S. Riggs in his 1903 and 1904 papers. The second, in the photo below, is the Potter Creek humerus, which was excavated from western Colorado in 1955 but not described until 1987, by Jim Jensen. That humerus, USNM 21903, resides at the National Museum of Natural History in Washington, D.C.

The Brachiosaurus humerus from Potter Creek, Colorado, on display at the Smithsonian.

For the sake of completeness, I have to mention that there is a humerus on display at the LA County Museum of Natural History that is labeled Brachiosaurus, but it’s not been written up yet, and after showing photos of it to colleagues, I’m not 100% certain that it’s Brachiosaurus (I’m not certain that it isn’t, either, but further study is needed). And there’s at least one humerus with a skeleton that was excavated by the University of Kansas and sold by the quarry owner to a museum in Korea (I had originally misunderstood this; some but not all of the material from that quarry went to KU), that is allegedly Brachiosaurus, but that one seems to have fallen into a scientific black hole. I can’t say anything about its identification because I haven’t seen the material.

Happy and relieved folks the morning after the Brachstraction: Yara Haridy, Matt Wedel, John and Ruby Foster, and the Bartletts: Kaler, Wes, Cobin, Resha, Jayleigh, and Thayne. Jacketed Brachiosaurus humerus for scale. Photo by Brian Engh.

So our pair of humeri from the Salt Wash of Utah are only the 3rd and 4th that I can confidently say are from Brachiosaurus. And they’re big. Both are at least 62cm wide across the proximal end, and the complete one is 201cm long. To put that into context, here’s a list of the longest sauropod humeri ever found:

  1. Brachiosaurus, Potter Creek, Colorado: 213cm
  2. Giraffatitan, MB.R.2181/SII specimen, Tanzania: 213cm
  3. Brachiosaurus, holotype, Colorado: ~213cm (preserved length is 203cm, but the distal end is eroded, and it was probably 213cm when complete)
  4. Giraffatitan, XV3 specimen, Tanzania: 210cm
  5. *** NEW Brachiosaurus, FHPR 17108, Utah: 201cm
  6. Ruyangosaurus (titanosaur from China): ~190cm (estimated from 135cm partial)
  7. Turiasaurus (primitive sauropod from Spain): 179cm
  8. Notocolossus (titanosaur from Argentina): 176cm
  9. Paralititan (titanosaur from Egypt): 169cm
  10. Patagotitan (titanosaur from Argentina): 167.5cm
  11. Dreadnoughtus (titanosaur from Argentina): 160cm
  12. Futalognkosaurus (titanosaur from Argentina): 156cm

As far as we know, our intact humerus is the 5th largest ever found on Earth. It’s also pretty complete. The holotype humerus has an eroded distal end, and was almost certainly a few centimeters longer in life. The Potter Creek humerus was missing the cortical bone from most of the front of the shaft when it was found, and has been heavily restored for display, as you can see in one of the photos above. Ours seems to have both the shaft and the distal end intact. The proximal end has been through some freeze-thaw cycles and was flaking apart when we found it, but the outline is pretty good. Obviously a full accounting will have to wait until the bone is fully prepared, but we might just have the best-preserved Brachiosaurus humerus yet found.

Me with a cast of the Potter Creek humerus in the collections at Dinosaur Journey in Fruita, Colorado. The mold for this was made from the original specimen before it was restored, so it’s missing most of the bone from the front of the shaft. Our new humerus is just a few cm shorter. Photo by Yara Haridy.

Oh, our Brachiosaurus is by far the westernmost occurrence of the genus so far, and the stratigraphically lowest, so it extends our knowledge of Brachiosaurus in both time and space. It’s part of a diverse dinosaur fauna that we’re documenting in the Salt Wash, that minimally also includes Haplocanthosaurus, Camarasaurus, and either Apatosaurus or Brontosaurus, just among sauropods. There are also some exciting non-sauropods in the fauna, which we’ll be revealing very soon.

A chunk of matrix from the brachiosaur quarry. The black bits are fossilized plants.

And that’s not all. Unlike most of the other dinosaur fossils we’ve found in the Salt Wash, including the camarasaur, apatosaur, and haplocanthosaur vertebrae I’ve shown in recent posts, the humeri were not in concrete-like sandstone. Instead, they came out of a sandy clay layer, and the matrix is packed with plant fossils. It was actually kind of a pain during the excavation, because I kept getting distracted by all the plants. We did manage to collect a couple of buckets of the better-looking stuff as we were getting the humerus out, and we’ll be going back for more.

As you can seen in Part 1 of Brian’s Jurassic Reimagined documentary series, we’re not out there headhunting dinosaurs, we’re trying to understand the whole environment: the dinosaurs, the plants, the depositional system, the boom-and-bust cycles of rain and drought–in short, the whole shebang. So the plant fossils are almost as exciting for us as the brachiosaur, because they’ll tell us more about the world of the early Morrison.

The Barletts: Thayne, Jayleigh, Resha, Cobin, Wes, and Kaler.

Among the folks I have to thank, top honors go to the Bartlett family. They came to work, they worked hard, and they were cheerful and enthusiastic through the whole process. Even the kids worked–Thayne was one of the driving forces keeping the wagon moving down the gulch, and the younger Bartletts helped Ruby uncover and jacket a couple of small bits of bone that were in the way of the humerus flip. So Wes, Resha, Thayne, Jayleigh, Kaler, and Cobin: thank you, sincerely. We couldn’t have done it without you all, and Molly and Darla!

EDIT: I also need to thank Casey Cordes–without his rope and winch skills, the jacket would still be out in the desert. And actually everyone on the team was clutch. We had no extraneous human beings and no unused gear. It was a true team effort.

The full version of the art shown at the top of this post: a new life restoration of Brachiosaurus by Brian Engh.

From start to end, this has been a Brian Engh joint. He found the humerus in the first place, and he was there for every step along the way, including creating the original paleoart that I’ve used to bookend this post. When Brian wasn’t prospecting or digging or plastering (or cooking, he’s a ferociously talented cook) he was filming. He has footage of me walking up to the humerus for the first time last May and being blown away, and he has some truly epic footage of the horses pulling the humerus out for us. All of the good stuff will go into the upcoming installments of Jurassic Reimagined. He bought the wagon and the boat winch with Patreon funds, so if you like this sort of thing–us going into the middle of nowhere, bringing back giant dinosaurs, and making blog posts and videos to explain what we’ve found and why we’re excited–please support Brian’s work (link). Also check out his blog,–his announcement about the find is here–and subscribe to his YouTube channel, Brian Engh Paleoart (link), for the rest of Jurassic Reimagined and many more documentaries to come.

(SV-POW! also has a Patreon page [link], and if you support us, Mike and I will put those funds to use researching and blogging about sauropods. Thanks for your consideration!)

The happiest I have ever been in the field. Photo by Yara Haridy.

And for me? It’s been the adventure of a lifetime, by turns terrifying and exhilarating. I missed out on the digs where Sauroposeidon, Brontomerus, and Aquilops came out of the ground, so this is by far the coolest thing I’ve been involved with finding and excavating. I got to work with old friends, and I made new friends along the way. And there’s more waiting for us, in “Brachiosaur Gulch” and in the Salt Wash more generally. After five years of fieldwork, we’ve just scratched the surface. Watch this space!

Media Coverage

Just as I was about to hit ‘publish’ I learned that this story has been beautifully covered by Anna Salleh of the Australian Broadcasting Corporation. I will add more links as they become available.


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:


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.


Arm lizard

December 16, 2019

Reconstructed right forelimb of Brachiosaurus at Dinosaur Journey in Fruita, Colorado, with me for scale, photo by Yara Haridy. The humerus is a cast of the element from the holotype skeleton, FMNH P25107, the coracoid looks like a sculpt to match the coracoid from the holotype (which is a left), and the other elements are either cast or sculpted from Giraffatitan. But it’s all approximately correct. The actual humerus is 204cm long, but the distal end is eroded and it was probably 10-12cm longer in life. I don’t know how big this cast is, but I know that casts are inherently untrustworthy so I suspect it’s a few cm shorter than it oughta be. For reference, I’m 188cm, but I’m standing a bit forward of the mount so I’m an imperfect scale bar (like all scale bars!). For another view of the same mount from five years ago, see this post.

So I guess the moral is that even thought this reconstructed forelimb looks impressive, the humerus was several inches longer, even before we account for any shrinkage in the molding and casting process, and the gaps between the bones for joint cartilage should probably be much wider, so the actual shoulder height of this individual might have been something like a foot taller than this mount. A mount, by the way, that is about as good as it could practically be, and which I love — I’m including all the caveats and such partly because I’m an arch-pedant, and partly because it’s genuinely useful to know all the ways in which a museum mount might be subtly warping the truth, especially if you’re interested in the biggest of the big.

All of which is a long walk to the conclusion that brachiosaurs are pretty awesome. More on that real soon now. Stay tuned.

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.


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.


  • 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.