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As the condensed mass of gas grows, it attracts more and more matter until the hot condensed matter forms a planet.
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Earth actually formed 4.54 billion years ago. *Note that it's 1= 1million scale
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As an asteroid crashed into earth, a shard of still molten earth got carried out and cooled, forming the moon.
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Oldest known gemstone (Zircon) , which is 4.4 billion years old, has been identified in Australia. Oskin, Becky. “Confirmed: Oldest Fragment of Early Earth Is 4.4 Billion Years Old.” LiveScience, Purch, 23 Feb. 2014, www.livescience.com/43584-earth-oldest-rock-jack-hills-zircon.html.
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The Young Earth is bombarded with asteroids and failed stars.
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Replicating molecules (the precursors of DNA) form.
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The asteroids bump into Earth significantly less now.
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Unicellular life evolves. Photosynthetic bacteria begin to release oxygen into the atmosphere.
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The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied.
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The very first Eon, The Earth is formed out of debris around the solar protoplanetary disk. There is no life. Temperatures are extremely hot, with frequent volcanic activity and hellish environments. The atmosphere is nebular. Possible early oceans or bodies of liquid water. The moon is formed around this time, probably due to a protoplanet's collision into Earth.
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Prokaryote life, the first form of life, emerges at the very beginning of this eon, in a process known as abiogenesis. The continents of Ur, Vaalbara and Kenorland may have been formed around this time. The atmosphere is composed of volcanic and greenhouse gases.
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The Eoarchean is the first era of the Archean Eon of the geologic record for which the Earth has a solid crust. It spans 400 million years from the end of the Hadean Eon 4 billion years ago to the start of the Paleoarchean Era 3600 Mya.
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The Paleoarchean, is a geologic era within the Archaean Eon. It spans the period of time 3,600 to 3,200 million years ago—the era is defined chronometrically and is not referenced to a specific level of a rock section on Earth. The name derives from Greek "Palaios" ancient.
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The Mesoarchean is a geologic era within the Archean Eon, spanning 3,200 to 2,800 million years ago. The era is defined chronometrically and is not referenced to a specific level in a rock section on Earth. Fossils from Australia show that stromatolites have lived on Earth since the Mesoarchean.
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The Neoarchean is a geologic era within the Archaean Eon. The Neoarchean spans the period from 2,800 to 2,500 million years ago—the period being defined chronometrically and not referenced to a specific level in a rock section on Earth.
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Eukaryotes, a more complex form of life, emerge, including some forms of multicellular organisms. Bacteria begin producing oxygen, shaping the third and current of Earth's atmospheres. Plants, later animals and possibly earlier forms of fungi form around this time. The early and late phases of this eon may have undergone "Snowball Earth" periods, in which all of the planet suffered below-zero temperatures.
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Paleoproterozoic Era, spanning the time period from 2,500 to 1,600 million years ago, is the first of the three sub-divisions of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's geological history. It was during this era that the continents first stabilized.
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The Siderian Period is the first geologic period in the Paleoproterozoic Era and lasted from 2500 Mya to 2300 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. The laying down of the banded iron formations peaked early in this period.
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The Rhyacian Period is the second geologic period in the Paleoproterozoic Era and lasted from 2300 Mya to 2050 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. The Bushveld Igneous Complex and other similar intrusions formed during this period.
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The Orosirian Period is the third geologic period in the Paleoproterozoic Era and lasted from 2050 Mya to 1800 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. The later half of the period was an episode of intensive orogeny on virtually all continents.
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The Statherian Period is the final geologic period in the Paleoproterozoic Era and lasted from 1800 Mya to 1600 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. The period was characterized on most continents by either new platforms or final cratonization of fold belts.
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The Mesoproterozoic Era is a geologic era that occurred from 1,600 to 1,000 million years ago. The Mesoproterozoic was the first period of Earth's history of which a fairly definitive geological record survives. Continents existed during the preceding era, but little is known about them.
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The Calymmian Period is the first geologic period in the Mesoproterozoic Era and lasted from 1600 Mya to 1400 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically.
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The Ectasian Period is the second geologic period in the Mesoproterozoic Era and lasted from 1400 Mya ago to 1200 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. Geologically the name refers to the continued expansion of platform covers during this period.
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The Stenian Period is the final geologic period in the Mesoproterozoic Era and lasted from 1200 Mya to 1000 Mya. Instead of being based on stratigraphy, these dates are defined chronometrically. The name derives from narrow polymetamorphic belts formed over this period.
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The Neoproterozoic Era is the unit of geologic time from 1,000 to 541 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran Periods. It is preceded by the Mesoproterozoic era and succeeded by the Paleozoic era.
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The Tonian is the first geologic period of the Neoproterozoic Era. It lasted from 1000 Mya to 720 Mya. Instead of being based on stratigraphy, these dates are defined by the ICS based on radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic era and followed by the Cryogenian.
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The Cryogenian is a geologic period that lasted from 720 to 635 million years ago. It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran.
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The Ediacaran Period, spans 94 million years from the end of the Cryogenian Period 635 million years ago, to the beginning of the Cambrian Period 541 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia.
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Multi-cellular marine organisms are common. The diverse assortment of life includes bizarre-looking animals like Wiwaxia.
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Complex life, like vertebrates, begin to dominate the Earth's ocean in a process known as the Cambrian explosion. Pangaea forms and later dissolves into Laurasia and Gondwana. Gradually, life expands to land and all familiar forms of plants, animals and fungi begin appearing, including annelids, insects and reptiles. Several mass extinctions occur, among which birds, the descendants of dinosaurs, and more recently mammals emerge.
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The Paleozoic Era is the earliest of three geologic eras of the Phanerozoic Eon. It is the longest of the Phanerozoic eras, lasting from 541 to 251.902 million years ago, and is subdivided into six geologic periods: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian.
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The Cambrian Period was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago to the beginning of the Ordovician Period 485.4 mya. Its subdivisions, and its base, are somewhat in flux
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Fish-like vertebrates evolve. Invertebrates, such as trilobites, crinoids, brachiopids, and cephalopods, are common in the oceans.
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The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya.
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Arthropods move onto the land. Their descendants evolve into scorpions, spiders, mites, and millipedes.
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The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period, 419.2 Mya.
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Land plants evolve, drastically changing Earth's landscape and creating new habitats.
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The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, 419.2 million years ago, to the beginning of the Carboniferous, 358.9 Mya. It is named after Devon, England, where rocks from this period were first studied.
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Four-limbed vertebrates move onto the land as seed plants and large forests appear. The Earth's oceans support vast reef systems.
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The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago, to the beginning of the Permian Period, 298.9 Mya.
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The Permian is a geologic period and system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic period 251.902 Mya. It is the last period of the Paleozoic era; the following Triassic period belongs to the Mesozoic era.
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The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by diapsids such as Iguanodon, Megalosaurus, Plesiosaurus and Pterodactylus.
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The Triassic is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago, to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the first period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events.
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The supercontinent called Pangea forms. Conifer-like forests, reptiles, and synapsids (the ancestors of mammals) are common.
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Over 90% of marine life and 70% of terrestrial life go extinct during the Earth's largest mass extinction. Ammonites are among the survivors.
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Dinosaurs and mammals evolve. Pangea has begun to break apart.
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The Jurassic was a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles.
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The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era, and the longest period of the Phanerozoic Eon.
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As the continents drift toward their present positions, the earliest flowers evolve, and dinosaurs dominate the landscape. In the sea, bony fish diversify.
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The Paleocene or Palaeocene, the "old recent", is a geological epoch that lasted from about 66 to 56 million years ago. It is the first epoch of the Paleogene Period in the modern Cenozoic Era.
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The Cenozoic Era meaning "new life", is the current and most recent of the three Phanerozoic geological eras, following the Mesozoic Era and extending from 66 million years ago to the present day.
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The Paleogene is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago to the beginning of the Neogene Period 23.03 Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon.
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A massive asteroid hits the Yucatan Peninsula, and ammonites and non-avian dinosaurs go extinct. Birds and mammals are among the survivors.
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The Eocene Epoch, lasting from 56 to 33.9 million years ago, is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch.
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The Oligocene is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present. As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain.
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The Neogene is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene.
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The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago. The Miocene was named by Charles Lyell; its name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene.
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In Africa, an early hominid, affectionately named "Lucy" by scientists, lives. The ice ages begin, and many large mammals go extinct.
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Quaternary is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy. It follows the Neogene Period and spans from 2.588 ± 0.005 million years ago to the present.
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The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology.