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Encyclopedia > Geological history of Earth
Geological time scale.

It is considered that the Earth was formed from a cloud of dust and gas drifting through space for about 4,570 Ma (million years ago). Denser minerals sank to the center whereas lighter ones formed a thin rocky crust. However, the first known life forms, bacteria and blue green algae, didn't appear until about 3,400 Ma (million years ago). It was about 700 Ma (million years ago) when more complex plants and animals came into existence. Since then numerous animal and plant species have evolved. Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Annum is a Latin noun meaning year. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Orders The taxonomy of the Cyanobacteria is currently under revision. ... Annum is a Latin noun meaning year. ... Annum is a Latin noun meaning year. ...


The geological history of the Earth can be broadly classified into three periods: the Precambrian supereon, the Phanerozoic eon and the Cenozoic eon. Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... The Precambrian (Pre-Cambrian) is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon. ... The Phanerozoic (occasionally Phaenerozoic) Eon is the period of geologic time during which abundant animal life has existed. ... The Cenozoic Era (IPA pronunciation: ); sometimes Caenozoic Era (in the United Kingdom), meaning new life (Greek (kainos), new, and (zoe), life), is the most recent of the three classic geological eras. ...


The first simple, sea dwelling organic structures appeared about 3,400 Ma (million years ago). It is considered that they may have formed when certain chemical (organic) molecules joined together. Prokaryotes, single-celled micro-organisms akin to blue green algae, were able to photosynthesize and produce oxygen. Around thousand million years later, sufficient oxygen had built up in the atmosphere and hence allow multicellular organisms to proliferate in the Precambrian seas. Soft-bodied jellyfish, corals, and sea worms flourished about 700 Ma (million years ago). Trilobites, the first animals with hard body frames, developed during the Cambrian period. About 363 Ma (million years ago) amphibians came into existence. It was only after the appearance of reptiles that animals were independent of water-living for their whole life cycle. Annum is a Latin noun meaning year. ... Prokaryotes (pro-KAR-ee-oht) (from Old Greek pro- before + karyon nut or kernel, referring to the cell nucleus, + suffix -otos, pl. ... The leaf is the primary site of photosynthesis in plants. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... View of Jupiters active atmosphere, including the Great Red Spot. ... Orders Stauromedusae Coronatae Semaeostomeae Rhizostomae Jellyfish are marine invertebrates belonging to the Scyphozoan class. ... Extant Subclasses and Orders Alcyonaria    Alcyonacea    Helioporacea Zoantharia    Antipatharia    Corallimorpharia    Scleractinia    Zoanthidea [1][2]  See Anthozoa for details For other uses, see Coral (disambiguation). ... Sea worm is a general term that may refer to a number of phyla of animals, or may refer specifically to: Acanthocephala, parasitic worm Annelida, Chaetognatha, Cycliophora, lobster worms Entoprocta, Echiura, Gastrotricha, microscopic Gnathostomulida, microscopic Hemichordata, Kinorhyncha, Loricifera, Micrognathozoa, microscopic Nematoda, round worms Nematomorpha, parasitic worms Nemertea, Onychophora, although mostly... Annum is a Latin noun meaning year. ... Orders Agnostida Nectaspida Redlichiida Corynexochida Lichida Phacopida Subclass: Librostoma Proetida Asaphida Harpetida Ptychopariida For the robot vacuum cleaner, see Electrolux Trilobite. ... Annum is a Latin noun meaning year. ... Subclasses Anapsida Diapsida Synonyms Reptilia Laurenti, 1768 Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class Sauropsida. ...

Contents

General history

Main article: History of Earth
Earth history mapped to 24 hours

Scientists have been able to reconstruct detailed information about the planet's past. Earth and the other planets in the Solar System formed 4.57 billion years ago[1] out of the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun. Initially molten, the outer layer of the planet Earth cooled to form a solid crust when water began accumulating in the atmosphere. The Moon formed soon afterwards, possibly as the result of a Mars-sized object with about 10% of the Earth's mass,[2] known as Theia, impacting the Earth in a glancing blow.[3] Some of this object's mass merged with the Earth and a portion was ejected into space, but enough material survived to form an orbiting moon.
Outgassing and volcanic activity produced the primordial atmosphere. Condensing water vapor, augmented by ice delivered by comets, produced the oceans.[4] The highly energetic chemistry is believed to have produced a self-replicating molecule around 4 billion years ago, and half a billion years later, the last common ancestor of all life existed.[5] The planet Earth, photographed in the year 1972. ... Image File history File links Earth_clock_hg. ... Image File history File links Earth_clock_hg. ... Major features of the Solar System (not to scale; from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth and its Moon, and Mars. ... This article or section does not cite any references or sources. ... Physics In physics, melting is the process of heating a solid substance to a point (called melting point) where it turns liquid. ... The Big Splash. ... For other uses, see Volcano (disambiguation). ... It has been suggested that multiple sections of steam be merged into this article or section. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... There are various popular theories as to how the worlds oceans were formed over the past 4. ... Last universal ancestor (LUA), the hypothetical latest living organism from which all currently living organisms descend. ...


The development of photosynthesis allowed the sun's energy to be harvested directly by life forms; the resultant oxygen accumulated in the atmosphere and resulted in a layer of ozone (a form of molecular oxygen [O3]) in the upper atmosphere. The incorporation of smaller cells within larger ones resulted in the development of complex cells called eukaryotes.[6] True multicellular organisms formed as cells within colonies became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized the surface of Earth.[7] The leaf is the primary site of photosynthesis in plants. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... It has been suggested that Ozone generator be merged into this article or section. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance transparent (gas) very pale blue (liquid) Atomic mass 15. ... The endosymbiotic theory concerns the origins of mitochondria and plastids (e. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... The ozone layer is the part of the Earths atmosphere which contains relatively high concentrations of ozone (O3). ...


As the surface continually reshaped itself, over hundreds of millions of years, continents formed and broke up. The continents migrated across the surface, occasionally combining to form a supercontinent. Roughly 750 million years ago (mya), the earliest known supercontinent Rodinia, began to break apart. The continents later recombined to form Pannotia, 600–540 mya, then finally Pangaea, which broke apart 180 mya.[8] In geology, a supercontinent is a land mass comprising more than one continental core, or craton. ... Depiction of Rodinia at time of initial breakup. ... Pannotia is the name given to a hypothetical supercontinent that existed from about 600 to about 540 mya. ... For other uses, see Pangaea (disambiguation). ...


Since the 1960s, it has been hypothesized that severe glacial action between 750 and 580 mya, during the Neoproterozoic, covered much of the planet in a sheet of ice. This hypothesis has been termed "Snowball Earth", and is of particular interest because it preceded the Cambrian explosion, when multicellular life forms began to proliferate.[9] Glacial and Glaciation redirect here. ... To help compare orders of magnitude of different times this page lists times between 1016 seconds (320 million years) and 1017 seconds (3200 million years). ... The Neoproterozoic Era is the unit of geologic time from 1,000 to 542 +/- 0. ... One computer simulation of conditions during the Snowball Earth period. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ...


Following the Cambrian explosion, about 535 mya, there have been five mass extinctions.[10] The last extinction event occurred 65 mya, when a meteorite collision probably triggered the extinction of the (non-avian) dinosaurs and other large reptiles, but spared small animals such as mammals, which then resembled shrews. Over the past 65 mya, mammalian life has diversified, and several mya, an African ape-like animal gained the ability to stand upright.[11] This enabled tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain. The development of agriculture, and then civilization, allowed humans to influence the Earth in a short time span as no other life form had,[12] affecting both the nature and quantity of other life forms. The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ... An extinction event (also known as: mass extinction; extinction-level event, ELE) occurs when there is a sharp decrease in the number of species in a relatively short period of time. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and the presence of hair, three middle ear bones used in hearing, and a neocortex region in the...


The present pattern of ice ages began about 40 mya, then intensified during the Pleistocene about 3 mya. The polar regions have since undergone repeated cycles of glaciation and thaw, repeating every 40–100,000 years. The last ice age ended 10,000 years ago.[13] Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ... The Pleistocene epoch (IPA: ) is part of the geologic timescale. ...


Geological timeline

Earth history has been divided into the various eras and periods of time of the geologic timescale based originally on the fossils found in the rocks. A geologic era is a subdivision of geologic time that is a separate classification that divides the Phanerozoic Eon into three parts timeframes. ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL is an acronym for Fido Opus Seadog Standard Interface Layer. ...



Millions of Years

Precambrian super-eon

Main article: Precambrian

The Precambrian (Pre-Cambrian) is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon.Precambrian includes approximately 90% of geologic time. It spans from the formation of Earth around 4500 Ma (million years ago) to the evolution of abundant macroscopic hard-shelled animals, which marked the beginning of the Cambrian, the first period of the first era of the Phanerozoic eon, some 542 Ma (million years ago). Precambrian is subdivided into 3 eons namely- The Precambrian (Pre-Cambrian) is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon. ... In general usage, an eon (sometimes spelled aeon) is a very long period of time. ... The Phanerozoic (occasionally Phaenerozoic) Eon is the period of geologic time during which abundant animal life has existed. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Annum is a Latin noun meaning year. ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ... Annum is a Latin noun meaning year. ...

  1. Hadean - (4.6 - 3.8 bya) During Hadean time, the Solar System was forming, probably within a large cloud of gas and dust around the sun, called an accretion disc.
  2. Archean - (3.8-2.5 bya) During this time, the Earth's crust cooled enough that rocks and continental plates began to form.
  3. Proterozoic - (2.5-0.57 bya) Stable continents appeared and began to accrete.

It is not known when life originated, but carbon in 3800 million year old rocks from islands off western Greenland may be of organic origin. Well-preserved bacteria older than 3460 million years have been found in Western Australia. Probable fossils 100 million years older have been found in the same area. There is a fairly solid record of bacterial life throughout the remainder of the Precambrian.
Excepting a few contested reports of much older forms from Texas and India, the first complex multicelled life forms seem to have appeared roughly 600 Ma (million years ago). A quite diverse collection of soft-bodied forms is known from a variety of locations worldwide between 542 and 600 Ma (million years ago). These are referred to as Ediacaran or Vendian biota. Hard-shelled creatures appeared toward the end of that timespan.
A very diverse collection of forms appeared around 544 Ma (million years ago), starting in the latest Precambrian with a poorly understood small shelly fauna and ending in the very early Cambrian with a very diverse, and quite modern Burgess fauna, the rapid radiation of forms called the Cambrian explosion of life. The name Hadean refers to the geologic period before 3800 million years ago (mya). ... Major features of the Solar System (not to scale; from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth and its Moon, and Mars. ... The Archean is a geologic eon; it is a somewhat antiquated term for the time span between 2500 million years before the present and 3800 million years before the present. ... Earth cutaway from core to exosphere. ... The Proterozoic (IPA: ) is a geological eon representing a period before the first abundant complex life on Earth. ... Animated, colour-coded map showing the various continents. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Capital Perth Government Constitutional monarchy Governor Ken Michael Premier Alan Carpenter (ALP) Federal representation  - House seats 15  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $100,900 (4th)  - Product per capita  $50,355/person (3rd) Population (December 2006)  - Population  2,050,900 (4th)  - Density  0. ... Official language(s) No Official Language See languages of Texas Capital Austin Largest city Houston Area  Ranked 2nd  - Total 261,797 sq mi (678,051 km²)  - Width 773 miles (1,244 km)  - Length 790 miles (1,270 km)  - % water 2. ... Annum is a Latin noun meaning year. ... Annum is a Latin noun meaning year. ... Dickinsonia costata, an Ediacaran organism of unknown affinity, with a quilted appearance. ... Annum is a Latin noun meaning year. ... The small shelly fauna is the name given to an obscure collection of small hard-shelled fossils found worldwide in beds a bit older than the earliest trilobites and archeocyathids in Nemakit-daldiyan stage (Lower Cambrian). ... Hallucigenia sparsa, one of the organisms unique to the Burgess Shale. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ...


Phanerozoic

Main article: Phanerozoic
During the Phanerozoic the biodiversity shows a steady but not monotonic increase from near zero to several thousands of genera.

The Phanerozoic (occasionally Phanaerozoic) Eon is the current eon in the geologic timescale, and the one during which abundant animal life has existed. It covers roughly 545 million years and goes back to the time when diverse hard-shelled animals first appeared. Its name derives from the Greek meaning visible life, referring to the large size of organisms since the Cambrian explosion. The time previous to the start of the Phanerozoic is called Precambrian (now divided into the Hadean, Archaean and Proterozoic eons). The exact time of the boundary between the Phanerozoic and the Precambrian is slightly uncertain. In the 19th Century, the boundary was set at the first abundant metazoan fossils. But several hundred taxa of Precambrian metazoa have been identified since systematic study of those forms started in the 1950s. Most geologists and paleontologists would probably set the Precambrian-Phanerozoic boundary either at the classic point where the first trilobites and archaeocyatha appear; at the first appearance of a complex feeding burrow called Trichophycus pedum; or at the first appearance of a group of small, generally disarticulated, armored forms termed 'the small shelly fauna'. The three different dividing points are within a few million years of each other.
The Phanerozoic is divided into three erasPaleozoic, Mesozoic, and Cenozoic. In the older literature, the term Phanerozoic is generally used as a label for the time period of interest to paleontologists. The term seems to be falling into disuse in more modern literature.
The time span of the Phanerozoic includes the rapid emergence of a number of animal phyla; the evolution of these phyla into diverse forms; the emergence of terrestrial plants; the development of complex plants; the evolution of fish; the emergence of terrestrial animals; and the development of modern faunas. During the period covered, continents drifted about, eventually collected into a single landmass known as Pangea and then split up into the current continental landmasses. The Phanerozoic (occasionally Phaenerozoic) Eon is the period of geologic time during which abundant animal life has existed. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Rainforests are among the most biodiverse ecosystems on earth Biodiversity is the variation of taxonomic life forms within a given ecosystem, biome or for the entire Earth. ... In general usage, an eon (sometimes spelled aeon) is a very long period of time. ... The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... The Cambrian explosion is the geologically kukko sudden appearance in the fossil record of the ancestors of familiar animals, starting about 542 million years ago (Mya). ... The Precambrian (Pre-Cambrian) is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon. ... The name Hadean refers to the geologic period before 3800 million years ago (mya). ... The Archean is a geologic eon; it is a somewhat antiquated term for the time span between 2500 million years before the present and 3800 million years before the present. ... The Proterozoic (IPA: ) is a geological eon representing a period before the first abundant complex life on Earth. ... Look up eon, Eon, EON in Wiktionary, the free dictionary. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Phyla Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented worms Tardigrada - Water bears Onychophora - Velvet worms Arthropoda - Insects, etc. ... FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL is an acronym for Fido Opus Seadog Standard Interface Layer. ... A taxon (plural taxa), or taxonomic unit, is a grouping of organisms (named or unnamed). ... the are cool The Geologist by Carl Spitzweg A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology). ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ... Orders Agnostida Nectaspida Redlichiida Corynexochida Lichida Phacopida Subclass: Librostoma Proetida Asaphida Harpetida Ptychopariida For the robot vacuum cleaner, see Electrolux Trilobite. ... The Archeocyatha, also called Archaeocyathids, were sessile, reef-building marine organisms that lived during the Lower Cambrian period (500-600 million years ago). ... Trichophycus pedum (or Treptichnus pedum; formerly Phycodes pedum) was one of the earliest animals, and the first found in great abundance. ... The small shelly fauna is the name given to an obscure collection of small hard-shelled fossils found worldwide in beds a bit older than the earliest trilobites and archeocyathids in Nemakit-daldiyan stage (Lower Cambrian). ... A geologic era is a subdivision of geologic time that is a separate classification that divides the Phanerozoic Eon into three parts timeframes. ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ... The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. ... The Cenozoic Era (IPA pronunciation: ); sometimes Caenozoic Era (in the United Kingdom), meaning new life (Greek (kainos), new, and (zoe), life), is the most recent of the three classic geological eras. ... Phylum (plural: phyla) is a taxon used in the classification of animals, adopted from the Greek phylai the clan-based voting groups in Greek city-states. ... This article is about evolution in biology. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... Animated, colour-coded map showing the various continents. ... Pangea may refer to: a common alternative spelling of the name Pangaea given to the supercontinent that is believed to have existed during the Paleozoic and Mesozoic eras Pangea, a geology equipment supplier/developer of mineralogical testing equipment Pangea (cable system), a submarine telecommunications cable system connecting the Netherlands and...


Cenozoic

Main article: Cenozoic
65 years climatic variations

The Cenozoic Era (IPA pronunciation: [ˌsiːnəˈzəʊɪk]); sometimes Caenozoic Era (in the United Kingdom), meaning "new life" (Greek καινός (kainos), "new", and ζωή (zoe), "life"), is the most recent of the three classic geological eras. It covers the 65.5 million years since the Cretaceous-Tertiary extinction event at the end of the Cretaceous that marked the demise of the last non-avian dinosaurs and the end of the Mesozoic Era. The Cenozoic era is ongoing.
The Cenozoic is divided into two periods, the Paleogene and Neogene, and they are in turn divided into epochs. The Paleogene consists of the Paleocene, Eocene, and Oligocene epochs, and the Neogene consists of the Miocene, Pliocene, Pleistocene, and Holocene epochs, the last of which is ongoing. Historically, the Cenozoic has been divided into periods (or sub-eras) named the Tertiary (Paleocene through Pliocene) and Quaternary (Pleistocene and Holocene).
The Cenozoic is the age of new life. During the Cenozoic, mammals diverged from a few small, simple, generalized forms into a diverse collection of terrestrial, marine, and flying animals. The Cenozoic is just as much the age of savannas, or the age of co-dependent flowering plants and insects. Birds also evolved substantially in the Cenozoic.
Geologically, the Cenozoic is the era when continents moved into their current positions. Australia-New Guinea split from Gondwana and drifted north and, eventually, adjacent to South-east Asia; Antarctica moved into its current position over the South Pole; the Atlantic Ocean widened and, later in the era, South America became attached to North America. The Cenozoic Era (IPA pronunciation: ); sometimes Caenozoic Era (in the United Kingdom), meaning new life (Greek (kainos), new, and (zoe), life), is the most recent of the three classic geological eras. ... Image File history File links // Description Expanded view of climate change during the last five million years, showing the rapid oscillations in the glacial state. ... Image File history File links // Description Expanded view of climate change during the last five million years, showing the rapid oscillations in the glacial state. ... Articles with similar titles include the NATO phonetic alphabet, which has also informally been called the “International Phonetic Alphabet”. For information on how to read IPA transcriptions of English words, see IPA chart for English. ... The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... Badlands near Drumheller, Alberta where erosion has exposed the KT boundary. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. ... Paleogene (alternatively Palaeogene) period is a unit of geologic time that began 65 and ended 23 million years ago. ... Neogene Period is a unit of geologic time consisting of the Miocene, Pliocene, Pleistocene, and Holocene epochs. ... Look up epoch in Wiktionary, the free dictionary. ... The Paleocene, early dawn of the recent, is a geologic epoch that lasted from 65. ... hfajhfiudshfas == == == --24. ... The Oligocene epoch is a geologic period of time that extends from about 34 million to 23 million years before the present. ... The Miocene Epoch is a period of time that extends from about 23. ... The Pliocene epoch (spelled Pleiocene in some older texts) is the period in the geologic timescale that extends from 5. ... The Pleistocene epoch (IPA: ) is part of the geologic timescale. ... The Holocene epoch is a geological period that extends from the present day back to about 10,000 radiocarbon years, approximately 11,430 ± 130 calendar years BP (between 9560 and 9300 BC). ... Tertiary geological time interval covers roughly the time span between the demise of the non-avian dinosaurs and beginning of the most recent Ice Age, approximately 65 million to 1. ... The Quaternary Period is the geologic time period from the end of the Pliocene Epoch roughly 1. ... Savanna at Ngorongoro Conservation Area, Tanzania. ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also called angiosperms) are the dominant and most familiar group of land plants. ... “Aves” redirects here. ... This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Animated, colour-coded map showing the various continents. ... Australia-New Guinea, also called Sahul or Meganesia, is made up of the continent of Australia and the islands of New Guinea and Tasmania. ... Gondwanaland redirects here. ... Location of Southeast Asia Southeast Asia is a subregion of Asia. ... For other uses, see South Pole (disambiguation). ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... World map showing North America A satellite composite image of North America. ...


See also

Wikimedia Commons has media related to:
Geological history of Earth

Image File history File links Commons-logo. ... The Wikimedia Commons (also called Wikicommons) is a repository of free content images, sound and other multimedia files. ... This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Timeline of geology: see also geologic timescale. ... // For other uses, see time scale. ... Wikipedia does not yet have an article with this exact name. ...

References

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  2. ^ Canup, R. M.; Asphaug, E. (Fall Meeting 2001). "An impact origin of the Earth-Moon system". Abstract #U51A-02, American Geophysical Union. Retrieved on 2007-03-10. 
  3. ^ R. Canup and E. Asphaug (2001). "Origin of the Moon in a giant impact near the end of the Earth's formation". Nature 412: 708-712. 
  4. ^ Morbidelli, A.; Chambers, J.; Lunine, J. I.; Petit, J. M.; Robert, F.; Valsecchi, G. B.; Cyr, K. E. (2000). "Source regions and time scales for the delivery of water to Earth". Meteoritics & Planetary Science 35 (6): 1309-1320. Retrieved on 2007-03-06. 
  5. ^ Doolittle, W. Ford (February , 2000). "Uprooting the tree of life". Scientific American 282 (6): 90-95. 
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  7. ^ Burton, Kathleen (November 29, 2000). Astrobiologists Find Evidence of Early Life on Land. NASA. Retrieved on 2007-03-05.
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Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... March 10 is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... March 6 is the 65th day of the year (66th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... This article is about the day. ... November 29 is the 333rd day of the year (334th in leap years) in the Gregorian calendar. ... 2000 (MM) was a leap year starting on Saturday of the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... This article is about the day. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... This article is about the day. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... This article is about the day. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... This article is about the day. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 112th day of the year (113th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... March 2 is the 61st day of the year (62nd in leap years) in the Gregorian calendar. ...

External links

  • Cosmic Evolution — a detailed look at events from the origin of the universe to the present
  • Valley, John W. “A Cool Early Earth?” Scientific American. 2005 Oct:58–65. – discusses the timing of the formation of the oceans and other major events in Earth’s early history.
  • Davies, Paul. “Quantum leap of life”. The Guardian. 2005 Dec 20. – discusses speculation into the role of quantum systems in the origin of life
  • Evolution timeline (uses Shockwave). Animated story of life since about 13,700,000,000 shows everything from the big bang to the formation of the earth and the development of bacteria and other organisms to the ascent of man.
  • Scientific American Magazine (October 2005 Issue) A Cool Early Earth?
  • Artist's Conception of Cold Early Earth

  Results from FactBites:
 
Geologic time scale - Wikipedia, the free encyclopedia (1940 words)
The geological time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the History of Earth.
The table of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy, and uses the standard color codes of the United States Geological Survey.
Until the discovery of radioactivity in 1896 and the development of its geological applications through radiometric dating during the first half of the 20th century which allowed for more precise absolute dating of rocks, the ages of various rock strata and the age of the Earth were the subject of considerable debate.
  More results at FactBites »

 
 

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