The Triassic-Jurassic extinction's effects on archosauromorphs

[Halichoeres]

The Triassic ended in a mass extinction that set the stage for the rest of the Mesozoic, wiping out or reducing many clades. This study uses a stitched together tree of archosauromorphs (dinosaurs, pterosaurs, crocodiles and relatives, and weird things like Erythrosuchus, Tanystropheus, and Dromomeron) based on other phylogenetic studies to try to figure out what determined extinction risk. They find that although there is a pretty clear bias in which groups were affected, body size didn't predict much of anything, and neither did other traits they looked at (diet, whether they were aquatic, etc.).

Open access! https://onlinelibrary.wiley.com/doi/epdf/10.1111/pala.12399

[Newt]

Obviously the ornithodirans were able to slip some bribes to the invading repticidal aliens. Cursed quislings!

[Halichoeres]

Obviously the ornithodirans were able to slip some bribes to the invading repticidal aliens. Cursed quislings!

The authors definitely dropped the ball when they neglected to evaluate this hypothesis.

[Vidusaurus]

Not quite sold on the utility of including genera like Erythrosuchus and Tanystropheus when their respective clades died out millions of years before the T-J extinction. Definitely scope for a more focused study here, but I'm not sure how useful these results are.

[Halichoeres]

I should clarify that the tree included archosauromorphs from across the Triassic because without them it wouldn't be possible to firmly resolve the position of end-Triassic taxa, but this study definitely did not count them as things that went extinct at the T-J boundary, even though in some cases their close relatives did. I mentioned the ones I did because I thought they would be familiar to more readers; a lot of the actual end-Triassic archosauromorphs I'd never heard of or was barely familiar with.