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 Same 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 Tech. 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

• Atterholt, Jessie, and Wedel, Mathew J. 2022. A computed tomography-based survey of paramedullary diverticula in extant Aves. The Anatomical Record 306(1): 29-50. https://doi.org/10.1002/ar.24923
• Schachner, Emma R., Andrew J. Moore, Aracely Martinez, Raul E. Diaz Jr, M. Scott Echols, Jessie Atterholt, Roger W. P. Kissane, Brandon P. Hedrick, & Karl T. Bates. 2024. The respiratory system influences flight mechanics in soaring birds. Nature 630: 671-676. (link)
• Wedel, M.J. 2024. The sauropod heresies: evolutionary ratchets, the taphonomic event horizon, and all the evidence we cannot see. The Jurassic: Death, Diversity, and Dinosaurs, 28th Annual Tate Conference abstract book: 35-38.
• Wedel, Mathew J., and Michael P. Taylor. 2013. Neural spine bifurcation in sauropod dinosaurs of the Morrison Formation: ontogenetic and phylogenetic implications. Palarch’s Journal of Vertebrate Palaeontology 10(1):1-34. ISSN 1567-2158.