Monthly Archives: June 2024

All the SV-POW! videos, and other stuff on the sidebar

BYU 11505, a caudal vertebra of a diplodocid from Dry Mesa, in posteroventral view. Note the paired pneumatic foramina on the ventral surface of the centrum.

If you want to find the paleontology and anatomy videos that Mike and I have done (plus one video about open access), they have their own sidebar page now, for your convenience and for our own. It’s, uh, just to the right of where your eyes are pointing right now. You know what, I’m sure you’ve got this.

Make a better living with extensively curated sidebar pages

In fact, we’ve added a few sidebar pages in the comparatively recent past (for a blog in its 17th year). In addition to the video page, we now have some project-specific pages, namely Mike’s Supersaurus, Ultrasaurus and Dystylosaurus in the 21st Century and Mike’s open projects pages, and my own Neural canal projects page. For now the global list of Haplocanthosaurus posts lives on the page for the Wedel et al. (2021) Haplocanthosaurus neural canal paper, but I imagine it’s only a matter of time until I add a page just to track all my business with Haplocanthosaurus. Also, ugh, I still have a few papers that I’ve blogged about, but which don’t have pages, and are therefore just that much harder to find.

And of course we still have all the old standbys: Tutorials, Things To Make and Do, The Shiny Digital Future, and so on.

It might seem kinda dumb to do a post alerting people to stuff that they can find for themselves, but the whole point of having the sidebar pages is that SV-POW! has gotten to be rather unmanageably vast, and anything that helps us — or even you! — get to the right posts quickly is a welcome assist.

The photo up top has nothing to do with any of this, I just thought it would be a fun way to meet our titular mandate.

 

doi:10.59350/390v5-1q318

New video: did air-filled bones allow dinosaurs to become gigantic?

My friend and frequent collaborator (one, two, three) Tito Aureliano invited me to give a talk on his YouTube channel, I suggested pneumaticity and gigantism, and here we are. There’s a decently lengthy Q&A, moderated by Tito, after the talk itself. Hilariously — and kindly — one of the commenters pointed out that I hadn’t explicitly answered the titular question in the talk, so I took a stab at it in the Q&A. I come on about 1:40, the talk starts about 5:20, and the Q&A starts at 1:24:30.

If you’ve seen any of my pneumaticity talks since, er, I gave my dissertation finishing talk in 2007, you’ve seen at least a few slides of this. But you won’t have seen all of them before, because a good number of them didn’t exist; this is sort of a Frankenstein stitched together from previous talks, new observations, and trying to think about the future. In particular, almost my entire 2012 SVPCA talk is crammed in near the end.

If in the talk I sound less certain about some things than I have in the past, that’s accurate. In the past few years I feel like I’ve accumulated a lot of interesting pieces (most of my post-2020 papers), and I’m in quest of a new synthetic foundation for my work (e.g., Taylor and Wedel 2021, this post), but I’ve also Seen Things that have rocked my certainty about my own level of understanding (e.g., Aureliano et al. 2023, this post). I’m cool with that. I think that whatever comprehension of pneumaticity I’m questing toward is going to have to emerge inductively from all the pieces, new and old, that I and others are producing. That’s an exciting prospect, and I’m having enough fun with the individual Legos that I’m in no tearing rush to guess what the final product will look like.

Many thanks to Tito for the invitation. After having just given a big talk that was a little speculative and a little outside my wheelhouse, it was nice to come back to home base, but hopefully still give people some useful things to take away. Time will tell.

 

doi:10.59350/7j0kz-v2s23

Fossil Friday grab-bag: bird diverticula, Oklahoma dinos, Tate trip pics, and more

BYU 12613, a very posterior cervical (probably C14 or C15) of a diplodocine sauropod, probably Kaatedocus or Diplodocus, from Dry Mesa, original fossil and 50% scale 3D print. The real bone has a mid-height centrum length of 270mm, compared to 642mm for C14 of D. carnegii.

I intended for the next post to be a follow-up on the new paper describing the Dry Mesa Haplocanthosaurus, as I hinted/promised in the last post. But that post is still gestating, there’s a lot of other cool stuff happening right now, and I don’t want to put off posting about it and risk never getting around to it.

Pneumatic diverticula in birds on the cover of Nature

I’m probably getting to be a crank on the subject of how pneumatic diverticula in birds are so grotesquely understudied. F’rinstance: the poultry industry is a $77 billion per year concern in the US alone, and the lung/air-sac system and its diverticula are a route for potentially lethal infections (which also affected sauropods), so you’d think we’d have the diverticular system of chickens and turkeys completely mapped, and its development fully charted. But we don’t!

See? Crank!

Anyway, Emma Schachner — who’s been doing awesome work in the arena of reptile and bird respiration for years (see here, here, and the comment thread here, for starters) — and colleagues just put bird diverticula on the map in a most spectacular fashion, with a cover article in Nature.

The short, short version is that Schachner et al. surveyed the sub-pectoral diverticulum (SPD) in 68 species of birds (in 42 families and 25 orders), and found that it was present in all soaring taxa, where it evolved at least 7 times, but absent in non-soarers. Furthermore, the SPD is in the right place to improve the mechanical advantage of the pectoralis muscles, which have a different architecture in soaring taxa, one that appears to be adapted in concert with the SPD for the particular demands of soaring flight. Schachner et al. illustrate their findings with just a ton of cool dissection photos, CT slices, and 3D reconstructions, in both the paper proper and the SI. Happily, the paper is a proper publication, 6 pages long and with plenty of detail, and not cut down to a glorified abstract.

Many things make me happy about this paper: the references to Owen (1836) and Strasser (1877), who independently suggested that the diverticula of birds might positively affect their flight dynamics; a strong team of authors taking a largely neglected anatomical system and spinning it into scientific gold; and the participation of my friends Raul Diaz and Jessie Atterholt. Together with our 2022 paper in the Anatomical Record, this is Jessie’s second taxonomically broad survey of a previously under-documented diverticular system in birds in just over two years, which is a heck of a (ahem) feather in her cap.

Given that birds have a whole internal zoo of diverticula that go between their muscles, among their viscera, under their skin, and into their bones — almost all of which are known from a bare handful of documented examples — I’m sure that there are many, many more exciting discoveries to make in this space. As Schachner et al. put it, “The discovery of a mechanical role for the respiratory system in avian locomotion underscores the functional complexity and heterogeneity of this organ system, and suggests that pulmonary diverticula are likely to have other undiscovered secondary functions.”

(If you’re thinking of not working on pneumaticity because some people are already working on [their own little corners of] it, perish the thought. At the current rate it could take decades just to document where the diverticula are and what they look like, let alone their functional implications. If the world can accommodate a new theropod phylogeny every couple of weeks, it can stand a lot more work on pneumaticity in birds and other dinos.)

Video: all the Oklahoma dinosaurs

My longtime friend and mentor, Kyle Davies, is the head preparator at the Sam Noble Oklahoma Museum of Natural History in Norman, where I did my undergrad and master’s work. Kyle is a phenomenally skilled morphologist, and if he needs something for education or exhibit that he can’t otherwise get hold of, he’ll just sculpt it himself — we’ve featured his work before (here and here). He recently gave a brown-bag lunch talk reviewing all of Oklahoma’s dinosaurs, and it’s just been posted to YouTube. Go have fun.

More travel and collections pics real soon

Luke Horton helping me get a shot of the right side of the ‘Jimbo’ Supersaurus dorsal on display at the Tate Geological Museum in Casper. The left side of this cast is visible in this post.

I just got back from a crazy-awesome research trip that I structured around the Tate Geological Museum’s 2024 summer conference. I got to spend time seeing the exhibits and working in the collections of a host of institutions, including:

  • the University of Wyoming Geological Museum in Laramie,
  • the Tate Museum in Casper,
  • the Wyoming Dinosaur Center in Thermopolis,
  • the Natural History Museum of Utah in Salt Lake City,
  • the Museum of Ancient Life in Lehi, Utah,
  • and — chronologically last but certainly not least — the BYU Museum of Paleontology in Provo.

At BYU I got three days to roam through the collections with Colin Boisvert, Brian Curtice, Ray Wilhite, and Gunnar Bivens. It was easily one of the most productive research trips I’ve ever had, rivaled only by the 2016 Sauropocalypse with Mike. In fact, we’d hoped that Mike would get to join me for part or all of the trip, but as luck would have it he had day job trips of his own in the same time frame. He did at least get to see the mounted cast of D. carnegii in Vienna, which he was keen to see.

This trip also had this in common with the 2016 Sauropocalypse: everywhere I went, curators, collections managers, and students were unfailingly kind, hospitable, and generous with their time and knowledge. Thanks in particular to Julian Diepenbrock, Laura Vietti, and Whitney Worrell in Laramie; JP Cavigelli, Dalene Hodnett, Shaedon Kennedy, and Rachel Stevens in Casper; Tom Moncrieffe and all the staff in Thermopolis; Carrie Levitt-Bussian at the NHMU; Rick Hunter and April Hullinger in Lehi; and Rod Scheetz, Colin Boisvert, Jacob Frewin, and Isaac Wilson at BYU.

Luke Horton measuring Tate v10533, a caudal vertebra of an apatosaurine from the Nail Quarry.

A special thanks to Luke Horton, who is currently an undergrad at Texas A&M. He made it out to Casper for the Tate conference and field trips, and he stuck around for a day afterward to assist me in collections. Given his passion for paleontology and his work ethic, I expect you’ll be hearing more about Luke in the not-too-distant future.

The upshot of all of this is that I have roughly a million cool things to post from the trip, many of which I’ll no doubt forget about or never get around to, but I will make an effort to convert trip photos into blog fuel this summer. The photo up top is the first snowball in what will hopefully become an avalanche. At BYU I was cruising down one of the aisles of sauropod vertebrae (yes, at BYU they have literally aisles of sauropod vertebrae — heaven!) and I did a double-take: it was my old friend BYU 12613! Mike and I figured that vert in our 2013 neural spine bifurcation paper, and I’d used the 50% scale 3D print in my Dolly video. I’d brought the print along on the trip as a handy visual and tactile aid for introducing people to sauropod cervical morphology, and I’d passed it around for show-and-tell during my Tate keynote talk. I couldn’t resist putting the real fossil and the 3D print together for a photo op. Here’s one more for the road, in postero-dorsal view this time:

In addition to blog posts, you’ll be seeing photos from this trip in presentations and papers as soon as it can be decently arranged. Stay tuned!

References

 

doi:10.59350/423d3-16z18

New paper out today on the Dry Mesa Haplocanthosaurus

Skeletal inventory of the Haplocanthosaurus bones found at Dry Mesa Dinosaur Quarry. Boisvert et al. (2024: fig. 2).

This morning saw the publication of my new paper with Colin Boisvert, Brian Curtice, and Ray Wilhite:

Boisvert, Colin, Curtice, Brian, Wedel, Mathew, & Wilhite, Ray. 2024. Description of a new specimen of Haplocanthosaurus from the Dry Mesa Dinosaur Quarry. The Anatomical Record, 1–19. http://doi.org/10.1002/ar.25520

Colin’s nexus of sauroponderous awesomeness

First off, big congratulations to Colin, who is having a banner season. On May 22 he gave his Masters thesis defense talk at BYU, on digital and physical articulation of the neck of BYU 18531, the “big pink apatosaur” from the Mill Canyon Quarry. You’ve seen that specimen in a few of our previous posts (notably here, midway down here, lurking in the background here), and Colin and his advisor, Brooks Britt, kindly gave Mike and me permission to publish some photos of one of the vertebrae in our recent cervical rib paper (Wedel and Taylor 2023).

As luck would have it, Colin is at NAPC this week, and this very morning he gave back-to-back talks. His second talk was a shorter version of his thesis defense talk, and his first talk was on (drumroll) Haplocanthosaurus: “Eleven specimens from ten locales in eight collections across three states, the diversity of known Haplocanthosaurus specimens in the Morrison Formation”, with Brian and Ray and me as coauthors. By sheer dumb luck, our paper dropped literally an hour or two before Colin’s Haplo talk, so when he got to the Dry Mesa individual he was able to plug the hot-off-the-presses new publication. That timing could not have been more perfect. Incidentally, the NAPC program and abstract book are both free downloads at this page; Colin’s abstracts are back-to-back on pages 125 and 126 (by internal numbering, pp. 135-136 of the PDF). 

Colin Boisvert, dropping knowledge at NAPC 2024.

 

It’s an especially momentous day because this is Colin’s first peer-reviewed journal publication — or, more accurately, of the several things he’s working on, this was the first to make it across the finish line. You’ll be hearing a lot more from Colin in the near future. (As Brian Curtice has pointed out, when someone has “vert” right in their name, we should be primed to expect great things. [NB: Colin’s last name is pronounced “bwa-VAIR” not “BOW-iss-vert”; replacing ‘vert’ with ‘air’ is, of course, the most sauropod-appropriate thing ever.]) We shall watch his career with great interest.

Enough back-patting, what’s this paper about anyway?

The quick version is that this paper is the longer, more complete, and more paleobiologically-informed version of our short paper for the 14th Symposium on Mesozoic Terrestrial Ecosystems and Biota (MTE14) last June (Curtice et al. 2023 and this post). As soon as we’d presented that, we realized that we needed to properly describe and illustrate every element of the Dry Mesa Haplo. Colin took point, and a year later, here we are.

So what do we have of this beast? Seven dorsal vertebrae and a right tibia, all found reasonably close together in a little pocket in the vast expanse of Dry Mesa Dinosaur Quarry. The vertebrae are obviously referable to Haplocanthosaurus because of their dorsally-oriented transverse processes, which instantly mark out Haplo from all the other known Morrison sauropods (note the caveat and hold that thought for the next a future post). The tibia is also referable to Haplo based on its chunkiness and the flared distal end, and it’s the right size to be from the same individual as the vertebrae. 

BYU 17531, a block of three anterior dorsal vertebrae preserved in articulation. The vertebrae are shown in right lateral (a), anterior (b), posterior (c), ventral (d), and dorsolateral (e) views. Scale bars are 10 cm. dp, diapophysis; hyp, hyposphene; nsp, neural spine; pcdl, posterior centrodiapophyseal lamina; pf, lateral pneumatic fossa; podl, postzygodiapophyseal lamina; poz, postzygapophysis; pp, parapophysis; prz, prezygapophysis; spol, spinopostzygapophyseal lamina. Boisvert et al. (2024: fig. 3).

Our best bit is BYU 17531, a series of 3 articulated anterior dorsal vertebrae. They record the migration of the parapophysis from low on the centrum up onto the neural arch, which is always nice to see. The block of three is a little sheared left-to-right, as shown in part D of the above figure. I’d love to get them CT scanned to investigate the articulations between the zygapophyses and the centra, a desire that only manifested as I was writing this post, looked again at the figure, and thought, “Oh, hey, intervertebral joint spacing!”

BYU 17530, a posterior dorsal vertebra. The vertebra is shown in anterior (a), posterior (b), left lateral (c), right lateral (d), dorsal (e), and ventral (f ) views. Scale bars are 10 cm. cprl, centroprezygapophyseal lamina; dp, diapophysis; hpn, hypantrum; hyp, hyposphene; lat. cpol, lateral centropostzygapophyseal lamina; nc, neural canal; pcdl, posterior centrodiapophyseal lamina; pf, pneumatic fossa; poz, postzygaphopysis; pp, parapophysis; prz, prezygapophysis; spdl, spinodiaapophyseal lamina; spol, spinopostzygapophyseal lamina; sprl, spinoprezygapophyseal lamina. Boisvert et al. (2024: fig. 6).

We also have four more posterior dorsals. I put them side-by-side in the skeletal inventory figure, but that was mostly out of laziness parsimony; most are too poorly preserved for us to get a firm fix on their serial position. We know that the best preserved of the bunch, BYU 17530, must be a pretty posterior dorsal, because the transverse processes are skinny and the neural spine is flared laterally (more anterior dorsals have dorsoventrally thicker transverse processes and narrower neural spines — see Hatcher 1903: plate 1, crucial bits of which are replicated at the top of this image).

Dorsal 12 of CM 572 in anterior (a), posterior (b) and right lateral (c) views, compared to BYU 17530, the best preserved posterior dorsal vertebra in anterior (d), posterior (e), and right lateral (f) views. Scale bar is 10 cm. Boisvert et al. (2024: fig. 7).

BYU 17530 is a pretty good match for D12 in CM 572, as shown in our figure 7. The top half of the anterior centrum face of the BYU vert is blown off, so we can see the large pneumatic fossae in the centrum, as well as the narrow median septum of bone that separates them. But that’s about the only significant damage, so I call BYU 17530 the “good dorsal”.

BYU 17689, a posterior dorsal vertebra. The vertebra is shown in anterior (a), posterior (b), left lateral (c), right lateral (d), dorsal (e), and ventral (f) views. Scale bars are 10 cm. cprl, centroprezygapophyseal lamina; dp, diapophysis; hpn, hypantrum; hyp, hyposphene; lat. cpol, lateral centropostzygapophyseal lamina; nc, neural canal; pcdl, posterior centrodiapophyseal lamina; pf, pneumatic fossa; poz, postzygaphopysis; pp, parapophysis; prz, prezygapophysis; spdl, spinodiapophyseal lamina; spol, spinopostzygapophyseal lamina; sprl, spinoprezygapophyseal lamina. Boisvert et al. (2024: fig. 8).

At the other end of the preservation quality spectrum, BYU 17689 is just happy to be here. The very tall neural arch pedicles and vaulted space over the neural canal are pure Haplo, and it’s from the same part of the quarry, same preservation, and right size to belong to our critter, but whew, that is a shard of excellence* for sure.

* For newer readers, sauropod vertebrae are never “pieces of crap”, no matter how badly broken. Rather, they are “shards of excellence”. The same idea could be extended to other clades. I can envision referring to poorly-preserved pneumatic vertebrae of theropods as “fragments of adequacy”. Broken ornithopod vertebrae are the “morning eye-boogers of Time”.

Haplocanthosaurus and Camarasaurus tibiae compared. USNM V 4275, a left Haplocanthosaurus tibia and astragalus (a), compared to BYU 12865, a right tibia (b), and YPM 5861, a left Camarasaurus tibia (c). Scale bar is 20 cm. The yellow line on USNM V 4275 represents the transition from tibia to astragalus. The cnemial crests for the two Haplocanthosaurus tibiae are incomplete. ap, anterior process; cc, cnemial crest; pp, posterior process. Boisvert et al. (2024: fig. 10).

The tibia, BYU 12865, is a little crushed and has some mid-shaft damage, but the flaring distal end is in good shape, enough to show that the bone is consistent with Haplocanthosaurus morphology.

What’s it all mean?

Why do we care about this critter?

First, as the title of Colin’s NAPC talk makes clear, there aren’t that many Haplos in the world — 11 to date, compared to over 200 for all the camarasaurs in the Morrison — so each new one is nice to have. In particular, the Dry Mesa Haplo has only the second set of articulated anterior dorsals for the genus, and the tibia helped us figure some things out regarding other Haplo specimens; more on that another time, perhaps.

Second, as we punched up in our MTE14 paper last year, this Haplocanthosaurus means that a minimum of six sauropod genera were present at Dry Mesa, making it the most diverse sauropod quarry in the world. I already wrote a whole post about that (link), so I’m not going to belabor it here, but it bears thinking about. Maybe six isn’t an unusual number of sauropods in an ecosystem, it just takes a quarry with 4000+ bones to capture them all. 

Third, a little push from our editor at the Anatomical Record got us thinking about why Haplocanthosaurus dorsal vertebrae are so distinctive. More on that in the next a future post.

For more posts on Haplocanthosaurus, see the running list on this page (link).

References

 

doi:10.59350/xfex2-2b397

Fossils of Jimbo the Supersaurus on exhibit

To answer Mike’s question from the last post, here’s a nice dorsal of Jimbo. All the material’s from the same quarry and has consistent preservation, and this dorsal is a monster. I didn’t try to measure it through the glass.

Hey guess what? It’s gonna be another really short photo post. Here are some pix of the Jimbo material on display at the Wyoming Dinosaur Center. Many thanks to Tom Moncrieffe of the WDC for taking a good chunk of his day to show me around.

Two partial cervical vertebrae, with part of a little one in between them, and a sectioned rib up on the shelf. I didn’t try to measure these through the glass either, but I’d estimate that each of the cervical centra is a meter and change in length, and both were a few cm longer when complete.

 

I don’t know if this pneumatic dorsal rib was too big, too dense, or too expensive to CT scan, but Dave Lovelace and colleagues did the next best thing: they sectioned it with a big rock saw. Pretty cool if you ask me.

 

Next cabinet going around clockwise has these dorsal vertebrae and a couple of broken neural spine tops. The vertebra on the left is the one shown in lateral view at the top of this post.

 

A tibia and a fibula. This is where it gets a little weird. I measured the other fibula, not on display, as being 116cm long. That sounds big, but it’s only a few cm larger than the fibulae of CM 3018 or AMNH 6341. So either Jimbo was unusually short-legged for the size of its vertebrae, or these limb bones belong to a different individual.

 

A proximal caudal and a huge chevron in the next cabinet.

 

And the rest of the caudals in that cabinet, a selection from different spots down the tail, with chevrons.

I have roughly 2376 interesting things I want to blog about, but my head is already about to split open with all the fascinating sauropod anatomy I’ve seen in the past few days, and I’m staring down the barrel of three more days of this. Stay tuned!

 

doi:10.59350/jp61r-esb50