Tropical climate throughout. First clubmosses and horsetails, then conifers become dominant plants. Major extinction at end of Permian marks end of Paleozoic. Triassic 225 Pangea begins to break up after 160 my of stability. Circumptropical Tethys Sea.
Climate begins to cool.
First flowering plants. Beginnings of 'boreotropical' flora in Laurasia. Extinction of dinosaurs and many other groups marks end of Mesozoic. Mammals evolve from Cretaceous ancestors in isolated groups on continental landmasses. Marsupials evolve in S. America and move to Australia via Antarctica, and to N. America and Europe.