SVP 2021 abstracts – 07: Trilophosaurus an archosauromorph? Still, no.

To, Stocker and Nesbitt 2021 report:
“The morphological details for rhamphotheca [= beaks] for nearly all archosaurs and archosauromorphs are lacking, despite their likely presence across multiple archosaurian lineages, because rhamphotheca are rarely preserved. Therefore, the early evolutionary history of rhamphotheca is poorly understood.

As readers know by now, paleo authors often set up this ‘poorly understood’ paradigm before presenting their eye-opening solution.

“Trilophosaurids are Late Triassic early diverging archosauromorphs with partial edentulism and an inferred rhamphotheca.

This is false. The early history of rhamphotheca would be ‘better understood’ if the three authors realized Trilophosaurus (Fig. 1) was a lepidosaur nesting (Fig. 2) more or less between the spenodontid, Brachyrhinodon (which also has a beak, Fig. 1), and the rhynchosaur, Hyperodapedon (whichs also has a beak, Fig. 1). We’ve known this here since 2011.

In the large reptile tree (LRT, 1988 taxa), which minimizes taxon exclusion by including so many taxa, Trilophosaurus is not an archosauromorph. So the present To, Stoker and Nesbitt study is off to a false and rocky start due to taxon exclusion.

To, Stocker and Nesbitt 2021 continue:
“However, no rhamphotheca has been preserved for this group and detailed osteocorrelates of the presence or extent of keratin are missing.

Fossils are rare. Fossils preserving keratin are vanishingly rare.

“Here, we provide a detailed description of the edentulous portion of the skull and mandible of the trilophosaurid Trilophosaurus buettneri to evaluate potential osteocorrelates of rhamphotheca in an early archosauromorph.

Good luck finding correlates in archosauromorphs, since Trilophosaurus is a lepidosaur.

“The premaxilla of Trilophosaurus lacks abrasive wear around the ventral margin, and the neurovascular foramina in the ventral surface have no discernable patterns, in contrast to clear clustering and regularity in the neurovascular foramina in turtles and probing birds.

So, now we’re comparing Trilophosaurus to unrelated turtles and birds. Not good.

The closest living relative of Trilophosaurus is the tuatara, Sphenodon (Fig 3). Let’s see how this study progresses when this taxon is someday included. Keywords ‘rhamphotheca’ and ‘Sphenodon’ bring up only one paper: pmc/articles/PMC2375800/

There must be a scarcity of interesting fossils
for professors to give to their students. Now professors are making their students find archosauromorph traits in lepidosauromorphs. If by accident, that is worse.

This recalls the ill-fated attempt
of Bristol University to find a volunteer willing to find evidence for quad-launch take-off tracks for pterosaurs. That’s called a snipe hunt here in the USA. The invalidated quad launch hypothesis had its genesis when new pterosaur worker, Mike Habib, cheated (or misunderstood) pterosaur morphology, as documented here. Nevertheless that hypothesis built on fantasy has since been supported by several British PhDs who subsequently became paleoartists. Quad-launch evidence has never been found and will never be found because it never happened.

Same with finding archosauromorph correlates in the lepidosaur, Trilophosaurus.
It’s a snipe hunt.

References
To K, Stocker M and Nesbitt S 2021. Tracing the archosaurian beakusing the Late Triassic archosauromorph Trilophosaurus buettneri. Journal of Vertebrate Paleontology abstracts.