The Carnian Pluvial Event was a time of major change for the earth and its supercontinent Pangaea. Namely, lots and lots of rain, and all the changes it brings. That was when the forests grew and dinosaurs began to rise to dominance, about 230 million years ago. From the images in this video from PBS Eons, that episode appears to be the line between the familiar (dinosaurs and forests) and the weird, weird, life forms that populated earth before that. -via Digg