Cary Woodruff

Balancing a Sauropod: The Physiology of a Dinosaur. By Brant E. Isakson. Academic Press. Amsterdam (The Netherlands) and New York: Elsevier. $106.25 (paper). xv + 144 p.; ill.; index. ISBN: 978-0-12-8...

AGH! I forgot to post it for #FossilFriday, but yesterday, my review of the book "Balancing a Sauropod: The Physiology of a Dinosaur" came out in The Quarterly Review of Biology. 2 second synopsis: Did I like it? No, I did not.

www.journals.uchicago.edu/doi/10.1086/...

If only I were at the meeting this year.....😪😪😪😪

I have laughed at this WAY more than I should! The satire in this is 🤌🏆

I knew going into A House of Dynamite that I was gonna cry. But never *THAT* that much. And I think about this subject. *A LOT*.

Kathryn Bigelow, @netflix.com, @nti.org, bravo!

This is an *exceptional* 'wake up' film. Please watch it. And please get everyone you know to watch it.

The expression on your face looks like you got a gift you don't want 😂

If this does happen, I'd be more than willing to help out 👍

I'm gonna replicate these methodologies on the very first articulated diplodocid rib series I get a hold of, and I suspect we'll see varied results - but why, and what it means will be immensely important to our understanding of 🦕 life history.

Differences between more basal and derived macronarians? Variations with greater or less pneumaticity? Widely variable amongst clades? ALL GOOD QUESTIONS! I LOVE this study, & it's a perfect example of the *many* challenges we still have with 🦕 life history studies.

By serially sampling the dorsal ribs in this titanosaur, Fronimos & Woodward showed that counter W&S, in this titanosaur the oldest life history data (an EFS) and most intact growth record was recorded in the posterior ribs.

But the Waskow & Sander study was in a Camarasaurus, and while I've followed this methodology in several diplodocoid studies, is this a 'rule' for all sauropods?

Waskow & Sander (2014) did a landmark study on the life history data preserved in 🦕 dorsal ribs. 🦕 are infamous for retaining a super shi%%y growth record, but this study showed that parts of ribs (anteriormost & rib 'neck') kept the growth record.

The structural preservation of a titanosaurid (Dinosauria: Sauropoda) vertebral ligament Within the past decade exceptional preservation of original organic components have been reported from several dinosaurian families, including members…

This specimen (cf. Alamosaurus[?]) is an essentially complete and articulated ~torso & hips, and I described this specimen back in 2016 because it preserves a large chunk of in situ 'nuchal'/interspinal ligaments!
www.sciencedirect.com/science/arti...

Ontogenetic assessment from dorsal ribs in a mature titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Texas Osteohistology has provided significant insights into the ontogeny and life history of the sauropod dinosaurs. However, the Titanosauria, which include Earth’s largest terrestrial vertebrates, exhi...

John A. Fronimos & Holly N. Woodward (2025)
Ontogenetic assessment from dorsal ribs in a mature titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Texas
Journal of Vertebrate Paleontology e2559012
doi: doi.org/10.1080/0272...

2) Fronimos & Woodward did an osteohisto age-determinate analysis on a remarkable titanosaur from Texas!

A long-necked early dinosaur from a newly discovered Upper Triassic basin in the Andes - Nature Discovery of a nearly complete skeleton of Huayracursor jaguensis, a Carnian dinosaur from the Northern Precordillera Basin in northwestern Argentina provides evidence of increased body size and early...

E. Martín Hechenleitner, Agustín G. Martinelli, Sebastián Rocher, Lucas E. Fiorelli, Malena Juarez, Jeremías R. A. Taborda & Julia B. Desojo (2025)
A long-necked early dinosaur from a newly discovered Upper Triassic basin in the Andes
Nature (advance online publication)
doi: doi.org/10.1038/s415...

1) #Huayracursor_jaguensis is a new sauropodomorph from the Late Triassic of Argentina. For any early dino that is an INSANELY complete skeleton! And check out those cervicals! Definitely an important taxon for understanding the evolutionary history of pod neck elongation.

We have a GREAT sauropod-themed #FossilFriday with two awesome studies that came out this week!
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HAPPY BIRTHDAY, HUNTER!!!!!! The big man turns **6** today! **SIX** Seems like just yesterday he was small enough to be my carry-on....😅 Here's to my love and the bestest boy on his bestest day, and may it be filled with tennis balls and cheeseburgers!

hamoni: in honor of Bob Harmon. Bob was the former head of the MOR lab and field program, and he was the best field mentor I've ever had. I learned so much from Bob, and I am the crew chief I am today thanks to his tutelage. Thank you Bob, for everything.
(📷 by A. Bailleul)

Now, on to the name: Brontotholus, which means Thunder Dome. Yes, a bit of a nod to the classic sauropod named "Brontosaurus", but primarily in homage to the classic 1985 film Mad Max Beyond Thunderdome.

But while there was no support for such a relationship between these 3, given the stratigraphic distribution & time between these Two Med specimens, we suggest that there *might* be a case for anagenesis within this new species (ex T. horridus -> T. prorsus).

Long story short, we found that these Two Med domes constituted a novel genus, and that this taxon was phylogenetically not close to either Stegoceras *OR* Pachycephalosaurus. So, no anagenetic relationship between these three.

Fast forward MANY YEARS later, & one of my dissertation chapters was to describe this Two Med dome (& 4 others) with my academic 'parents' - Dave Evans and Jack Horner, and 'committee uncle' Mark Goodwin.

Horner et al (1992) proposed that a dome from the Two Medicine Fm was an anagenetic intermediate between the stratigraphically older Stegoceras & the younger Pachycephalosaurus. & given our understanding of their taxonomy at the time, that wasn't a crazy hypothesis.

Barring debate, the case for anagenesis in these proposed lineages has mixed support: present in tyrannosaurids and ceratopsians, less so in the hadrosaurs. But one lineage from the 1992 paper had yet to be tested: Pachycephalosauria.

In 1992, Horner et al published a landmark paper that examined the regression/transgression of the Western Interior Seaway in regards to dino evolution, and postulated that many NA dino lineages underwent a not-controversial-at-all-process (he said facetiously) called anagenesis.

Pachycephalosaurs are mostly known from the Late Cretaceous (save Zavacephale from the Early Cret.), & there are many taxa known from NA formations like the Judith, Dinosaur Park, Oldman, & Hell Creek Formations. But none from the Judithian ~coeval Two Medicine Fm. Until now...

Let's start with the paper:
(I also put it on ResearchGate)
The first pachycephalosaurid from the Late Cretaceous Two Medicine Formation: effects of the Western Interior Seaway on North American pachycephalosaurid evolution.
doi: doi.org/10.1093/zool...