280 Mya to 260 Mya

272.95 Mya, Permian, Guadalupian, Radian: Pelycosaurs, and therapsids, Synapsid reptiles, become plentiful 

268.8 Mya, Permian, Guadalupian, Wordian: End of glaciation? Synapsid reptiles (pelycosaurs and therapsids)are plentiful while parareptiles and temnospondyl amphibians remain common.

265.1 Mya, Guadalupian, Capitanian: End of Permo Carboniferous glaciation,

220,000,000 BP to 200,000,000 BP

220,ooo,ooo BP t0 200,000,000 BP 

 200,000,000 BP to 145,000,000 BP: This is the time of the Jurassic Period. This Geological Period fell between the Triassic and Cretaceous Periods. It was during this time that the super contnent Pangaea began to drift apart and to begin much of our present continental geography. During this period there was lots of life, a wet climate, and lush vegetation. Many new dinosaurs appeared. Conifers appeared. Mammals were common, but small. There is evidence of early birds and lizards. Were there worms then or not? There was a lessor extinction toward the end of this Period.

200,000,000 BP: Pangea still exists united, but faults begin to define the continents of today.

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.

                                                                                                                    rcs

Why Is There No "comments" Apps for this Blog

                            I do not know. I believe that a comments'' app was available when I began this blog. And it was usual for Blogspot to have an easy set up at Settings, Now the setup app at settings does not function here nor on several other of my blogs.

                                                                                    Richard Sheehan

1,500,000 BP t0 500,000BP

1,500,000 BP to 500,000,BP

 1,300,000 BP: Henry's Fork Caldera.Yellowstone hotspot, Mesa Falls Tuff, Idaho, US. Ejecta volume 2809 km3

1,25,000 BP: Super volcano. Valles Caldera. Jemez volcanic field. New Mexico, USA. Two eruptions 1,25 and 1.61 million years ago. Ejecta volume 600 km3.

160,000,000 BP to 140,000,000 BP

160,000,000 BP to 140,000,000 BP

145,000,000 BP to 140,000,000 BP: time of the Berriasian Age of the Cretacious Period.

145,000,000 BP to 66,000,000 BP: Cretaceous Period is divided into two Ages: the Valanginian Age and the Berriasian Age. During this time placental mammals appear. It is also the time of the beginnings of the Laramide and Sevier orogenies of Rocky Mountains of North America. Atmospheric co2 was close to present day levels.

140 Mya to 130 Mya: This is the Valanginan Age of the Cretaceous Period.

140,000,000 BP to 120,000,000 BP

 140 Mya to 120 Mya, millions of years ago

140,000,000 BP to 130,000,000 BP: time of the Valanginian Age of the Cretaceous Period.

135,000,000 BP, Cretaceous period: Flowering plants appeared at this time an diversify into the main flowering plant families we know today.

132,000,000 BP: The pillars of Hercules were not and the gates of Atlanta were not closed. The Atlantic ocean penetrated deep into what is now the Sahara.

0.126 Mya, Late Pleistocene, sometimes called the Tarantian: Eemian interglacial, Last glacial period ending with the Younger Dryas. Toba eruption. Megafauna extinction.

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.

1,000,000 BP to 500,000 BP

 

 

 

 800,000 BP: There may well have been neanderthal type of people in what is now Europe. Neanderthals may have continued to occupy the area for several 100,000 years.

~ Also about this time a large volcanic eruption occurred at Kyushu, Japan. Four large eruptions continued there between 300,000 and 80,000 BP.

 

A Brief History of Geologic Time

200 Mya to 180 Mya

 200 Mya to 180 Mya

usage notes: Mya points to "millions of years ago I referens to "before the present;"

 

 

 

 200 Mya: Pangea existed as present continents united.

200 Mya to 145 Mya: This is the duration of the Jurassic geological Period. The Jurassic Period fell between the Triassic and Cretaceous Periods,

~ The super continent Pangaea began to drift apart during this Period.

~ There was lots of life, wet climate, and lush vegetation. Many new dinosaurs appeared. Conifers appeared. Mammals were common, but small. There is evidence of early birds and lizards, our first evidence of them.

~ There was a "minor"extinction toward the end of this period.

200,000,000 BP: At this very beginning of the Jurassic Period

Pangea exists. Present continents become defined but are still united. 

 

201,000,000 BP to 152,000,000 BP: Jurassic Period: This period was been divided into the Early, Middle, and Late Jurassic. The Early Jurassic is made up of four ages: the Hettangia, the Sineemurian,, the Pliensbachisan, and the Toarcian. We have begun a geological timeline. I'll add that there were already some small mammals around at this early age,

 

 

 

 

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.