420 Mya to 300 Mya: Including the Devonian Period

420 Mya to 300 Mya   Mya means million years ago.

 

419.2 Mya to ca 360 Mya, Earth: The Devonian period of the the Paleozoic era. This period has been divided to early, middle, and late parts. the late part ending in a mass extinction event.

251.9 Mya to 201.3, Triassic:This is the first geological of the Mesozoic Era. The Triassic falls between the Permian and Jurassic Periods. At this time a first evidence of mammals was seen, a mouse size critter. This geologic period ended with a mass extinction of species.

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300,000,000 BP to 280,000,000 BP

 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.

260 Mya to 240 Mya

 260 Mya to 240 Mya

 Usage notes: "Mya" means "million years ago" These dates are amazing close approximations, but are subject to adjustments

259. 0.4 Mya, Lopingian, Wuchiapingian: Marking the end of the Permo-Carboniferous glaciation.

254.14 Mya, Paleozoic, Permian, Lopingian, Changhsingian: Land masses unite into supercontinent Pangaea and creating the Appalachian range.

251.9 Mya to 201.3 Mya: Duration of the Triassic Period of the Mesozoic Era. The Triassic Period is between the Permian and Cretaceous Periods.

~ First evidence of mammals occurred in this Period. One was a mouse size critter.

~ This geologic period ended with a mass extinction of species. So, 251,900,000 BP marked a mass extinction of life.

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.