Xavier Jenkins

🪂

Beetle grows ‘termite’ on back to steal food Puppet helps insect trick real termites into feeding it

In what may be one of Earth’s craziest forms of mimicry, researchers in 2023 reported a species of rove beetle that grows a termite puppet on its back to fool real termites into feeding it.

Learn more during #InsectWeek: scim.ag/40mj1S8

Claws are present in many non-amniotes, including basically the entire amniote stem however way you look at it

Happy to announce that this fall I’ll be a Kalbfleisch and Frick Postdoctoral Research fellow at the American Museum of Natural History @amnh.org

I’ll work with Dr. Roger Benson on more early reptile evolution, sensory anatomy, and more. Super excited!

Huge thanks!!

Thank you (:

Also thanks to @adamfitch.bsky.social for letting me know I tagged Zoie twice in the first version of this post 😅

Thanks to all of my friends and colleagues for all of their help, I couldn’t have done it without you (:

Brandon Peecook prepares to introduce Xavier as Xavier nervously drinks a coffee

Xavier presents a slide thanking his kids for being adorable

Xavier and Zoie smile on THE helicoprion couch

Xavier and Brandon smile on that same Helicoprion couch, but this time Xavier doesn’t know what to do with his arms

Successfully passed my dissertation defense here at ISU! These past five years have been amazing. Fell in love with research, started my family with @thezoiejenkins.bsky.social , and couldn’t have asked for a better advisor in @gondwannabe.bsky.social #Dissertation #PhD

I am not surprised, and I am probably late to the game here in realizing this. But gross! Poor undergrads or the occasional googler...

Gemini is using Pterosaur Heresies as one of it's sources now. Extremely concerning...

The neodiapsid Thadeosaurus colcanapi from the upper Permian of Madagascar The enigmatic neodiapsid Thadeosaurus colcanapi (Lower Sakamena Formation, southwestern Madagascar), sole species of the genus Thadeosaurus, is revised here. The attribution of 12 of the 21 referred ...

Extremely detailed paper on the anatomy Thadeosaurus, with increased phylogenetic support for Tangasauridae 🦎 🌊 onlinelibrary.wiley.com/doi/10.1002/...

This is pretty much the norm among most Paleozoic fenestrated amniotes. Tubers, ridges, bumps, or striae are present on most early synapsids and reptiles that I’ve seen (including Heleosaurus in my PFP), probably for similar reasons as hypothesized by Sharpe 👀

The St. George Dinosaur Discovery Site is looking for help with funding and crews to excavate an ~1/2 acre of bone beds in the Early #Jurassic (~200 million). We need big excavation equipment. Check out fossils and how you can help in the images attached.

Postdoc on stegosaurs with Roger Benson at the AMNH careers.amnh.org/postings/4384

Both even hypothesize that this morphology was indicative of a secondarily closed ‘UTF’ but it didn’t gain much traction elsewhere, outside of an acknowledgement by Romer (1956) IIRC

Watson (1957) and I think even Gow (1972) diagnosed Millerettidae as having a ‘free ventral flange of the parietal’ or something to that effect

Illustration of Millereta basking in top of a rock

Close up of the head and anterior body of Millereta

Here is my reconstruction of Millereta rubidgei, an early #reptile from Late Permian South Africa. It has osteoderms on its head.

I was commissioned to do this recon for a redescription published yesterday! Congrats to @semifossorial.bsky.social and colleagues for such a cool paper!

#paleoart

Gabriel is one of the best! 📌

And our amazing artwork of Milleretta, brought to life by
@serpenillus.bsky.social
😀 #Permian #Fossil #Reptile #Paleontology

Some amazing paleoart by @serpenillus.bsky.social to be posted soon 😃

I’m on track to publish on a couple of other millerettids soon (including everyone’s favorite reptile: Broomia perplexa), so may 2025 be remembered as the Year of Millerettidae, if nothing else 😳

By this point you hopefully know that 1) Milleretta is cool and 2) I love braincases. Both of these facts combine into one when we look at the inner ear of this taxon, which is surprisingly derived. Large, arcing semicircular canals and a larger lagena than many early amniotes.

Like other millerettids, there is a tympanic fossa shared by the quadrate, quadratojugal, and squamosal 🤔

The stapes is robust, but lacks features present in earlier-diverging reptiles such as a dorsal process. It also does not serve as a brace of the skull, but rather ends freely

This suggests that many of Broom’s co-eval millerettids, distinguished primarily based on differences in temporal fenestra architecture and size, represent juvenile or subadult Milleretta.

Sorry ‘Millerosaurus’ fans, M. nuffieldi and M. ornatus may not be distinct taxa 😢

This is achieved by a combination of the development of the posterior process of the jugal and the ventral flange of the parietal, but also other elements.

In juveniles, the postorbital is shorter and does not contact the supratemporal.

Milleretta also closes a lower temporal fenestra AND a ‘gap’ in the region of the Neodiapsid upper temporal fenestra through ontogeny. This latter feature is diagnostic for all millerettids.

I don’t think that this gap actually represents a UTF, but that Permian reptile skulls are a bit nuanced

Milleretta is a complicated taxon to work on for a couple of reasons. Number 1 being…cranial osteoderms!

Milleretta bears cranial osteoderms that rest on top of the skull bones, obliterating external sutures. This is particularly true for the antorbital region of mature individuals

Also peep the pretty standard maxillary canal and lacrimal puncti, fitting the narrative that early reptiles had more simple maxillary canals than their synapsid brethren 🐄