Re: [dinosaur] Causes for dinosaur dominance at the end of the Triassic

There is also a significant turnover in the middle Norian about 215 Ma
(Adamanian-Revueltian in NA) that also might have played a significant
role in what diversity and disparity was remaining in vertebrates by
the ETE. I've presented on this at several meetings now, most recently
at NAPC 2019. Work is ongoing.

On Sun, Aug 4, 2019 at 4:16 AM David Marjanovic <[email protected]> wrote:
>
> > if you were to answer the question what caused the dominance of dinosaurs in the late Triassic, what would you say? My guess is 1) more efficient respiratory system and 2) better anatomic adaptations for fast movement. Any other (better) thoughts?
>
> The end of the Triassic is marked by a mass extinction. After it, there happened to be dinosaurs, pterosaurs and crocodylomorphs left, while all other kinds of archosaurs were gone. Add the extinction of the dicynodonts except apparently in Australia, and that's a lot of open ecological space.
>
> Within the Triassic, the Carnian Pluvial Episode (about 233 Ma ago) marks a smaller faunal turnover that is not well understood yet, but there were more dinosaurs after it than before. Depending on seemingly contradictory radiometric dates, this late date may even be when such noticeable predators as *Cynognathus* and the erythrosuchids went extinct.