Link that works: journals.plos.org/plosone/arti...

While this site is exceptional insofar as the metoposaurids are concerned, it has so much more to offer in improving our understanding of the paleoecology of the continental early Late Triassic in North America!

16/16

Last but certainly not least, plants and poops. None of us is a paleobotanist, so take our IDs with a grain of salt. These might represent some of the more complete plants from the Popo Agie, but we'd love to work with someone interested in Triassic plants. And coprolites too...

15/16

The bivalves from NK have unironically become my favorites because they are a bit of a puzzle. Only external molds on + and - relief! We propose they formed by 1) burial, 2) dissolution of biomineral and retention of outer organic layer, 3) lithification, and 4) loss of organic layer. 🤷‍♂️

14/16

"Fish bits" from within the bonebed including what we think is an almost complete fin. We suggest these are all redfieldiid based on the supracleithrum, but it's possible if not likely there were other ray-finned fish present. We need more complete fish material!

13/16

The shed archosauriform teeth are from the bonebed, but this partial phytosaur mandible is from somewhere in the overburden. It's the lowest definitive occurrence of a phytosaur from the Popo Agie aside from some unsubstantiated reports.

12/16

Now for the critters! The star of the show is Buettnererpeton bakeri, a metoposaurid species placed in its own genus by @koskinonodon.bsky.social and me a couple years back. That little block with articulated palatal plates (E,F) was found by Bryan when he came out to the site in 2018!

11/16

Tangent: I don't find the "breeding colony die-off" hypothesis in some previous studies particularly convincing because 1) post-breeding die-off is fairly specialized among vertebrates and 2) afaik, it's unknown among any modern amphibians.

10/16

Still, the cause of death is unknown. I wish we knew what the sediment looks like lateral to the bonebed, but we keep finding bones! If there are mudcracks in the same layer like Site XIII, that would suggest drying, and if not, then it could be biological such as an algal bloom or disease.

9/16

So is Nobby Knob more of the same or is it different?

It's different! Nobby Knob exhibits more even representation of the skeleton than two other bonebeds analyzed by us and likely than both Lamy and Rotten Hill (although raw count data were not accessible for these two sites).

8/16

A similar depositional scenario was suggested for the Rotten Hill bonebed in Texas by the same group of workers (not imaged for brevity). So no North American metoposaurid MMAs appear to be deposited in low energy settings like a drying pond.

7/16

TL;DR: Several studies from workers at NMMNHS have demonstrated that the Lamy quarry has undergone sorting and some transportation and is likely the result of a sheetflooding event.

📸 Rinehart et al. (2024) a newly prepared slab from Lamy and the alignment of long bones

6/16

Romer initially interpreted the Lamy quarry as a "drying pond" scenario, but subsequent workers suggest that this is an oversimplification. They use several lines of evidence looking at sediment, long bone orientation, skeletal representation, etc. If you want to know more, we cited them!

5/16

Previous metoposaurid MMAs from North America are all high energy deposits and are highly sorted so that most remains that...remain are highly immobile elements such as large flat skull roofs, clavicles, and interclavicles.

📸 Romer (1939) the slab at MCZ from the Lamy amphibian quarry in NM

4/16

Metoposaurid bonebeds are relatively common (as far as vert paleo assemblages go). We named this one Nobby Knob, and it is the first unequivocal mass mortality assemblage (MMA) of metoposaurids from the Popo Agie Fm.

3/16

Here we describe the taphonomy of a #metoposaurid bonebed from the Late Triassic Popo Agie Formation of Wyoming. I have been presenting on this site for several years at conferences, so I'm thrilled to finally have it published!

2/16

No need to see the rest of this. A dead #metoposaurid is enough for me