Your Friends The Titanosaurs: Bustingorrytitan shiva

In terms of dinosaurs, 2023 is going to go out like it came in: with a new plus-sized Huincul Formation titanosaur. This one has been delivered just in time for Christmas, although it's unlikely to fit under anyone's tree. Of course, there have been some comments that it is not as big as has been published, but regular readers will know not to get too wrapped up in these things.

10 years of Equatorial Minnesota

So... turns out I've been doing this 10 years. The very first post on Equatorial Minnesota went out December 15, 2013. Here we are, 409 posts and one surprisingly sprawling Compact Thescelosaurus later. I'm hoping there will be many more posts to come, because I still have many ideas, even if the pace has slowed down (lots of other things going on).

For fun, here are some posts from the first five full years that I'm particularly fond of, for various reasons:

2014:

• Practical guide to to MNNRA/metro-area bedrock geology
  
• "The generic history of dinosaur paleontology" series (final part)
• Sponge detective: when faunal lists go bad
• A brief history of dinosaurs on the Internet
• Designasaurus II

2015:

• Historic Twin Cities geologic maps and photos
• Reports of gut contents in herbivorous dinosaurs
• "Where are they now" series (final part)
• Coming Attractions in Dinosauria?
• Nodosaurus: more than a corduroy armadillo 

2016:

• A tale of two packrat species
  
• Gonioceras: when a nautiloid is also a shovel-flounder
• Cambrian island-hopping at Taylors Falls
• Stegopelta
  
• A locked dinosaur mystery
• (former) Ash beds in St. Paul
• The Great Minnesota Brachiopod Caper of 1892
• Club Late Ordovician

2017:

• George William Featherstonhaugh
• Further adventures in the Mazomanie
• The limitations of the layer cake
• Follow-up: Pipestone National Monument, Scenella, Cylindrocoelia
  
• 75 years of "Hadrosaurian Dinosaurs of North America"
• Life on Mill Street

2018:

• Practical guide to St. Croix Valley sedimentary formations
• Titanosaurs all the way down, the start of the ongoing series 
• Identifying invertebrate fossils
• Fun with nautiloids: an essay in futility
• Big Ordovician brachiopods: Strophomena and friends
• Lower Decorah trilobites
• Dryosaurus elderae and the revenge of Nanosaurus agilis
• Rebbachisauridae
• Decorah gastropods (and some things that look like gastropods)

Release the robotic Pleurocystites!

Speaking of paleobiology, here's a fun story that crossed my desk recently...

If you've ever seen a fossil of Pleurocystites or its ilk, you've probably wondered what the heck it was doing in life (and perhaps how disturbing it may have looked while doing it). What once was confined to the realm of speculation now takes a step, or more accurately a kind of thrash, into the 21st century with the "Rhombot", a robotic pleurocystitid detailed in Desatnik et al. (2023).

The rhombots use the basic form of a pleurocystitid: central capsular body (theca), two short appendages (brachioles) at one end, one long appendage (stem) at the other end. The body plan is scaled-up in comparison to the real thing, and, of course, it is made of various artificial materials (many of which are not rigid, hence the "soft robotics" tag) rather than pleurocystitid stuff.

Pleurocystitids, thrashing their way from Ordovician seafloors to the modern day via the rhombot (Figure 1, Desatnik et al. 2023) (CC BY-NC-ND-4.0).

Granted, a rhombot is not a direct replica of a Pleurocystites. Assuming the living thing did indeed use its stem for propulsion, what can we gather from a robotic equivalent? First off, the rhombot was much more efficient with the stem moving it from behind rather than pulling it along. (This seems like a common-sense conclusion on first principles, so it's good to see it confirmed.) The stem also was more effective when used with a stiff sweep, rather than working with a sinuous motion. Finally, there was an optimal length for the stem (Desatnik et al. 2023). I encourage you to go to the linked article and see the movies of rhombots in action; they are not the most graceful robots, but pleurocystitids were probably not the most graceful animals.

References

Desatnik, R., Z. J. Patterson, P. Gorzelak, S. Zamorad, P. LeDuca, and C. Majidi. 2023. Soft robotics informs how an early echinoderm moved. Proceedings of the National Academy of Sciences 120(46):e2306580120. doi: https://doi.org/10.1073/pnas.2306580120.