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

["David Marjanovic" <david.marjanovic@gmx.at>]

> 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.