300,000,000 to 280,000,000 BP
298.9 Mya, Cisuralian, Asselian: The firs true mosses, beetles and flies evolve.
Marine flourish in warm shallow seas.
295 Mya, Cisuralian, Sakmarian: Coal age flora are being replaced by cone-bearing gymnosperms, the first true seed plants
290.1 Mya, Cisuralian, Artinskian: Amphibians are common. Cone bearing flora appearing.
283.5 Mya, Paleozoic, Permian, Cisuralian, Kungurian: Parareptiles and temnospondyl amphibians are common.
251,900,000 BP to 201,300,000 BP: Triassic Period: This time has been called the Triassic Period. The Triassic Period falls after the Permian Period and before the Jurassic Period. First evidence of mammals appear, a mouse like critter is found to lie within the Period. This geologic period ended with a mass extinction of species.