Many ferns, cycads, gingkos, rushes, conifers, ammonites , and pterosaurs . Minor extinctions at 190 and 160 mya. Triassic Period 248 to 208 mya The first dinosaurs , mammals, and crocodyloformes appear. Mollusks are the dominant invertebrate. Many reptiles, for example, turtles, ichthyosaurs .
True flies appear.
This allowed the dinosaurs to expand into many niches. Gymnosperms dominant plant life. The continents merge into a single super-continent, Pangaea . Phtyoplankton and plants oxygenate the Earth's atmosphere to close to modern levels. The first stoneflies, true bugs, beetles, and caddisflies, The Permian ended with largest mass extinction .