Timeline of natural history
Encyclopedia
This timeline of natural history summarizes significant cosmological, geological and biological events from the formation of the Universe to the beginning of the Stone Age
.
s and the jovian planets
were formed. The inner solar system aggregated slower than the outer, so the terrestrial planets were not yet formed, including Earth
and Moon
.
Stone Age
The Stone Age is a broad prehistoric period, lasting about 2.5 million years , during which humans and their predecessor species in the genus Homo, as well as the earlier partly contemporary genera Australopithecus and Paranthropus, widely used exclusively stone as their hard material in the...
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Formation of the Universe
- 13.7 ± 0.2 billion years: estimated age of the universeUniverseThe Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
according to the Big BangBig BangThe Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
theory - 13.2 billion years: age of the oldest known star, HE 1523-0901HE 1523-0901HE 1523-0901 is the designation given to a red giant star located in the Milky Way galaxy approximately seven and a half light-millennia from Earth. It is thought to be a second generation Population II, or metal-poor, star . The star was found in the sample of bright metal-poor halo stars from the...
- 12.7 billion years: age of the quasarQuasarA quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
CFHQS 1641+3755
The earliest Solar System
In the earliest solar system history, the sun, the planetesimalPlanetesimal
Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks.A widely accepted theory of planet formation, the so-called planetesimal hypothesis of Viktor Safronov, states that planets form out of cosmic dust grains that collide and stick to form larger and larger...
s and the jovian planets
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
were formed. The inner solar system aggregated slower than the outer, so the terrestrial planets were not yet formed, including Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
and Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
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- c. 4570 million years ago (Ma): A supernovaSupernovaA supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
explosion seeds our galactic neighborhood with heavy elements that will be incorporated into the Earth, and results in a shock waveShock waveA shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...
in a dense region of the Milky WayMilky WayThe Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
galaxy. The Ca-Al-rich inclusionsCa-Al-rich inclusionsA calcium-aluminium-rich inclusion or Ca-Al-rich Inclusion is a submillimeter to centimeter-sized light-colored calcium- and aluminium-rich inclusion found in carbonaceous chondrite meteorites...
, which formed 2 million years before the chondrules, are a key signature of a supernovaSupernovaA supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
explosion. - 4567±3 Ma: Rapid collapse of hydrogenHydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
molecular cloudMolecular cloudA molecular cloud, sometimes called a stellar nursery if star formation is occurring within, is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen ....
, forming a third-generation Population I star, the SunSunThe Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, in a region of the Galactic Habitable Zone (GHZ), about 25,000 light years from the center of the Milky Way Galaxy. - 4566±2 Ma: A protoplanetary disc (from which Earth eventually forms) emerges around the young SunSunThe Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, which is in its T TauriT Tauri starT Tauri stars are a class of variable stars named after their prototype – T Tauri. They are found near molecular clouds and identified by their optical variability and strong chromospheric lines.-Characteristics:...
stage. - 4560–4550 Ma: Proto-Earth forms at the outer (cooler) edge of the habitable zoneHabitable zoneIn astronomy and astrobiology, a habitable zone is an umbrella term for regions that are considered favourable to life. The concept is inferred from the empirical study of conditions favourable for Life on Earth...
of the Solar SystemSolar SystemThe Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. At this stage the solar constantSolar constantThe solar constant, a measure of flux density, is the amount of incoming solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit...
of the sun was only about 73% of its current value, but liquid water may have existed on the surface of the Proto-earth, probably due to the greenhouse warmingGreenhouse effectThe greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere...
of high levels of methaneMethaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
and carbon dioxideCarbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
present in the atmosphere.
Hadean Eon
- 4533 Ma: Hadean Eon, PrecambrianPrecambrianThe Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
Supereon and Cryptic eraCryptic eraThe Cryptic era is an informal term that refers to the earliest geologic evolution of the Earth and Moon. It is the oldest era of the Hadean eon, and it is commonly accepted to have begun close to 4567.17 million years ago when the Earth and Moon formed...
start as the EarthEarthEarth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
–MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
system forms, possibly as a result of a glancing collision between proto–Earth and the hypothetical protoplanetProtoplanetProtoplanets are large planetary embryos that originate within protoplanetary discs and have undergone internal melting to produce differentiated interiors. They are believed to form out of kilometer-sized planetesimals that attract each other gravitationally and collide...
Theia. (The Earth was considerably smaller than now, before this impact.) This impact vaporized a large amount of the crust, and sent material into orbit around Earth, which lingered as rings for a few million years, until these rings condensed into the Moon. The Moon geology pre-NectarianPre-NectarianThe Pre-Nectarian Period of the lunar geologic timescale runs from 4533 million years ago to 3920 million years ago, when the Nectaris Basin was formed by a large impact. It is followed by the Nectarian period...
period starts. Earth was covered by a magmaMagmaMagma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...
tic ocean 200 kilometres (124.3 mi) deep resulting from the impact energy from this and other planetesimalPlanetesimalPlanetesimals are solid objects thought to exist in protoplanetary disks and in debris disks.A widely accepted theory of planet formation, the so-called planetesimal hypothesis of Viktor Safronov, states that planets form out of cosmic dust grains that collide and stick to form larger and larger...
s during the early bombardment phase, and energy released by the planetary corePlanetary coreThe planetary core consists of the innermost layer of a planet.The core may be composed of solid and liquid layers, while the cores of Mars and Venus are thought to be completely solid as they lack an internally generated magnetic field. In our solar system, core size can range from about 20% to...
forming. Outgassing from crustal rocks gives Earth a reducingRedoxRedox reactions describe all chemical reactions in which atoms have their oxidation state changed....
atmosphere of methaneMethaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
, nitrogenNitrogenNitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, hydrogenHydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
, ammoniaAmmoniaAmmonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, and water vapour, with lesser amounts of hydrogen sulfideHydrogen sulfideHydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...
, carbon monoxideCarbon monoxideCarbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
, then carbon dioxideCarbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. With further full outgassing over 1000–1500 K, nitrogen and ammonia become lesser constituents, and comparable amounts of methane, carbon monoxide, carbon dioxide, water vapour, and hydrogen are released. - 4450 Ma: 100 million years after the Moon formed, the first lunar crustGeology of the MoonThe geology of the Moon is quite different from that of the Earth...
, formed of lunar anorthositeAnorthositeAnorthosite is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar , and a minimal mafic component...
, differentiates from lower magmaMagmaMagma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...
s. The earliest Earth crust probably forms similarly out of similar material. On Earth the pluvialPluvialIn geology and climatology, a pluvial was an extended period of abundant rainfall lasting many thousands of years. Pluvial is also applied to the sediments of these periods . The term is especially applied to such periods during the Pleistocene Epoch...
period starts, in which the Earth's crust cools enough to let oceans form. - 4404 Ma: First known mineralMineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
, found at Jack HillsJack HillsThe Jack Hills are a range of hills in Mid West Western Australia. They are best known as the source of the oldest material of terrestrial origin found to date: zircons that formed around 4.4 billion years ago...
in Western AustraliaWestern AustraliaWestern Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. DetritalDetritusDetritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
zirconZirconZircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. A common empirical formula showing some of the range of substitution in zircon is 1–x4x–y...
s show presence of a solid crustCrust (geology)In geology, the crust is the outermost solid shell of a rocky planet or natural satellite, which is chemically distinct from the underlying mantle...
and liquidLiquidLiquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
waterWaterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. Latest possible date for a secondary atmosphereSecondary atmosphereA secondary atmosphere is an atmosphere of a planet that did not form by accretion during the formation of the planet's sun. A secondary atmosphere instead forms from internal volcanic activity, or by accumulation of material from comet impacts...
to form, produced by the Earth's crust outgassingOutgassingOutgassing is the release of a gas that was dissolved, trapped, frozen or absorbed in some material. As an example, research has shown how the concentration of carbon dioxide in the Earth's atmosphere has sometimes been linked to ocean outgassing...
, reinforced by water and possibly organic molecules delivered by cometCometA comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
impacts and carbonaceous chondriteCarbonaceous chondriteCarbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 7 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites...
s (including type CI shown to be high in a number of amino acids and polycyclic aromatic hydrocarbonPolycyclic aromatic hydrocarbonPolycyclic aromatic hydrocarbons , also known as poly-aromatic hydrocarbons or polynuclear aromatic hydrocarbons, are potent atmospheric pollutants that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH...
s (PAH)). - 4150 Ma: Unofficial Basin GroupsBasin GroupsBasin Groups refers to 9 informal subdivisions of the lunar Pre-Nectarian geologic period.-Definition:The motivation for creating the Basin Groups subdivisions was to place 30 pre-Nectarian impact basins into 9 relative age groups...
Era starts. - 4100 Ma: Acasta GneissAcasta GneissThe Acasta Gneiss is a rock outcrop of Hadean tonalite gneiss in the Slave craton in Northwest Territories, Canada. Located on an island about 300 kilometres north of Yellowknife, the Acasta River rock deposit, believed to be 4.031 to 3.58 billion years old, is the oldest known intact crustal...
of Northwest Territories, Canada, first known oldest rockOldest rockThe oldest dated rocks on Earth, as an aggregate of minerals that have not been subsequently melted or disaggregated by erosion, are from the Archean Eon. Such rocks are exposed on the surface in very few places....
, or aggregate of minerals. - 3920 Ma: Unofficial NectarianNectarianThe Nectarian Period of the lunar geologic timescale runs from 3920 million years ago to 3850 million years ago. It is the period during which the Nectaris Basin and other major basins were formed by large impact events...
Era starts. - 3920–3850 Ma: Late heavy bombardmentLate Heavy BombardmentThe Late Heavy Bombardment is a period of time approximately 4.1 to 3.8 billion years ago during which a large number of impact craters are believed to have formed on the Moon, and by inference on Earth, Mercury, Venus, and Mars as well...
of the Moon (and probably of the Earth as well) by bolides and asteroidAsteroidAsteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s, produced possibly by the planetary migrationPlanetary migrationPlanetary migration occurs when a planet or other stellar satellite interacts with a disk of gas or planetesimals, resulting in the alteration of the satellite's orbital parameters, especially its semi-major axis...
of NeptuneNeptuneNeptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...
into the Kuiper beltKuiper beltThe Kuiper belt , sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets extending from the orbit of Neptune to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it is far larger—20 times as wide and 20 to 200 times as massive...
as a result of orbital resonanceOrbital resonanceIn celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
s between JupiterJupiterJupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
and SaturnSaturnSaturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
. - 3850 Ma: Unofficial Lower ImbrianLower ImbrianIn the lunar geologic timescale, the Early Imbrian epoch occurred between 3850 million years ago to about 3800 million years ago. It overlaps the end of the Late Heavy Bombardment of the inner solar system. The impact which created the huge Mare Imbrium basin occurred at the start of the epoch...
Era starts. - 3850 Ma: Greenland apatiteApatiteApatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, chlorapatite and bromapatite, named for high concentrations of OH−, F−, Cl− or Br− ions, respectively, in the crystal...
shows evidence of 12C enrichment, characteristic of the presence of photosynthetic life. - 3850 Ma: First evidence of life: Akilia islandAkilia islandAkilia Island is an island in southwestern Greenland, about 22 kilometers south of Nuuk , at . Akilia is the location of a rock formation that has been proposed to contain the oldest known sedimentary rocks on Earth,...
graphiteGraphiteThe mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
off Western GreenlandGreenlandGreenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
contains evidence of kerogenKerogenKerogen is a mixture of organic chemical compounds that make up a portion of the organic matter in sedimentary rocks. It is insoluble in normal organic solvents because of the huge molecular weight of its component compounds. The soluble portion is known as bitumen. When heated to the right...
, of a type consistent with photosynthesisPhotosynthesisPhotosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
.
Eoarchaean
- 3800 Ma: Archean Eon and EoarcheanEoarcheanIn the geologic record the Eoarchean erathem and the Eoarchean era in the geologic timescale correspond to one another in the dual system of classification of rock strata laid down beginning 4000 Ma to 3600 Ma .- Chronology :It was formerly officially unnamed and usually referred to as the first...
Era start. - 3800 Ma: Oldest banded iron formationBanded iron formationBanded iron formations are distinctive units of sedimentary rock that are almost always of Precambrian age. A typical BIF consists of repeated, thin layers of iron oxides, either magnetite or hematite , alternating with bands of iron-poor shale and chert...
s found.
Paleoarchaean
- 3600 Ma: PaleoarcheanPaleoarcheanThe Paleoarchean is a geologic era within the Archaean. It spans the period of time 3600 Ma to 3200 Ma —the period being defined chronometrically and not referenced to a specific level in a rock section on Earth. The oldest ascertained life form is from this period....
Era starts. Possible assembly of the VaalbaraVaalbaraVaalbara is theorized to be Earth's first supercontinent, beginning its formation about , completing its formation by about and breaking up by . The name Vaalbara is derived from the South African Kaapvaal craton and the West Australian Pilbara craton...
supercontinent - 3500 Ma: Fossils resembling cyanobacteria, found at Warrawoona, Western AustraliaWestern AustraliaWestern Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. - 3460 Ma: Fossils of bacteriaBacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
in chertChertChert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
. - 3300 Ma: Onset of compressional tectonics
Mesoarchaean
- 3200 Ma: MesoarcheanMesoarcheanThe Mesoarchean is a geologic era within the Archean, spanning 3200 Ma to 2800 Ma . The period 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. The Pongola...
Era starts. - 3200–2600 Ma: Assembly of the Ur supercontinentUr (continent)Ur was a supercontinent that formed in the early Archean eon; the oldest continent on Earth, half a billion years older than Arctica. Ur joined with the continents Nena and Atlantica about to form the supercontinent Rodinia...
to cover between 12–16% of the current continental crustContinental crustThe continental crust is the layer of igneous, sedimentary, and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called sial due to more felsic, or granitic, bulk composition, which lies in...
. - 2900 Ma: Assembly of the KenorlandKenorlandKenorland was one of the earliest supercontinents on Earth. It is believed to have formed during the Neoarchaean Era ~2.7 billion years ago by the accretion of Neoarchaean cratons and the formation of new continental crust...
supercontinent, based upon the core of the Baltic shieldBaltic ShieldThe Baltic Shield is located in Fennoscandia , northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton...
, formed at 3100 Ma.
Neoarchaean
- 2800 Ma: NeoarcheanNeoarcheanThe Neoarchean is a geologic era within the Archaean. It spans the period of time from —the period being defined chronometrically and not referenced to a specific level in a rock section on Earth...
Era starts. Breakup of the VaalbaraVaalbaraVaalbara is theorized to be Earth's first supercontinent, beginning its formation about , completing its formation by about and breaking up by . The name Vaalbara is derived from the South African Kaapvaal craton and the West Australian Pilbara craton...
supercontinent - 2736 Ma: Formation of the Temagami greenstone beltTemagami greenstone beltThe Temagami greenstone belt, also known as the Temagami volcanic belt and the Temagami metavolcanic belt, is a small 2.7 billion year old greenstone belt in the Temagami region of Northeastern Ontario, Canada...
in Temagami, OntarioOntarioOntario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean... - 2705 Ma: Major komatiiteKomatiiteKomatiite is a type of ultramafic mantle-derived volcanic rock. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content...
eruption, possibly global - 2700 Ma: Biomarkers of cyanobacteria discovered, together with steranes (sterolSterolSterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol...
s of cholesterolCholesterolCholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
), associated with films of eukaryotes, in shales located beneath banded iron formation hematite beds, in Hamersley Range, Western Australia Skewed sulfur isotope ratios found in pyrites shows a small rise in oxygen concentration in the atmosphere - 2600 Ma: Oldest known giant carbonate platform
Paleoproterozoic
- 2500 Ma: Proterozoic Eon, Paleoproterozoic Era, and SiderianSiderianThe Siderian 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....
Period start. Banded iron formationBanded iron formationBanded iron formations are distinctive units of sedimentary rock that are almost always of Precambrian age. A typical BIF consists of repeated, thin layers of iron oxides, either magnetite or hematite , alternating with bands of iron-poor shale and chert...
s form during this period. Earth's atmosphere starts to become oxygenicOxygen CatastropheThe Great Oxygenation Event , also called the Oxygen Catastrophe or Oxygen Crisis or Great Oxidation, was the biologically induced appearance of free oxygen in Earth's atmosphere. This major environmental change happened around 2.4 billion years ago.Photosynthesis was producing oxygen both before...
. Assembly of ArcticaArcticaArctica was an ancient continent which formed approximately 2.5 billion years ago in the Neoarchean era.Arctica consisted of the Canadian and Siberian shields, and is now roughly situated in the Arctic around the current North Pole.- History :...
out of the Canadian Laurentian Shield and SiberianSiberia (continent)Siberia is the craton located in the heart of the region of Siberia. Siberia or "Angaraland" is today the Central Siberian Plateau...
cratonCratonA craton is an old and stable part of the continental lithosphere. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates. They are characteristically composed of ancient crystalline basement rock, which may be covered by...
. - 2400 Ma: HuronianHuronianThe Huronian glaciation extended from 2400 Mya to 2100 Mya, during the Siderian and Rhyacian periods of the Paleoproterozoic era, triggered by the oxygen catastrophe, which oxidised the atmospheric methane...
glaciation starts, probably from oxidation of earlier methane greenhouse gas produced by burial of organic sediments of photosynthesizers. First cyanobacteria. - 2300 Ma: Rhyacian period starts.
- 2200–1800 Ma: Continental Red BedsContinental Red BedsThe Kem Kem Beds is a geological formation in Morocco and Algeria whose strata date back to the Late Cretaceous...
found, produced by iron in weathered sandstone being exposed to oxygen. - 2200 Ma: Iron content of ancient fossil soils shows an oxygen built up to 5–18% of current levels
- 2100 Ma: HuronianHuronianThe Huronian glaciation extended from 2400 Mya to 2100 Mya, during the Siderian and Rhyacian periods of the Paleoproterozoic era, triggered by the oxygen catastrophe, which oxidised the atmospheric methane...
glaciation ends. Earliest known eukaryoteEukaryoteA eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
fossils found. Earliest multicellular organisms (Francevillian Group FossilFrancevillian Group FossilThe Francevillian Group Fossil is an early, macroscopic organism. They were centimeter-sized highly organized, spatially discrete colonial organisms. Their fossils are found in the west-African country of Gabon in the Palaeoproterozoic Francevillian B Formation, a 2.1-Gyr-old black shale...
) - 2050 Ma: OrosirianOrosirianThe Orosirian 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....
Period starts. Significant orogenyOrogenyOrogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...
in most continents. - 2023 Ma: VredefortVredefortVredefort is a small farming town in the Free State province of South Africa with cattle, peanuts, sorghum, sunflowers and maize being farmed. It is home to 3,000 residents....
impact structure forms. - 2000 Ma: The lesser supercontinentSupercontinentIn geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
AtlanticaAtlanticaAtlantica is the name given to an ancient continent that formed during the Proterozoic about from various 2 Ga cratons located in what is now West Africa and eastern South America....
forms. The OkloOkloOklo is a region near the town of Franceville, in the Haut-Ogooué province of the Central African state of Gabon. Several natural nuclear fission reactors were discovered in the uranium mines in the region in 1972.-History:...
natural nuclear reactor of GabonGabonGabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
produced by uranium-precipitant bacteria. First acritarchAcritarchAcritarchs are small organic fossils, present from approximately to the present. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion.-Definition:In general, any small, non-acid soluble Acritarchs are small organic fossils, present from...
s. - 1850 Ma: Sudbury impact structureSudbury BasinThe Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario, Canada. It is the second-largest known impact crater or astrobleme on Earth, as well as one of the oldest....
. Penokean orogenyPenokean orogenyThe Penokean orogeny was a mountain-building episode that occurred in the early Proterozoic about 1.85 to 1.84 billion years ago, in the area of North America that would eventually become Minnesota, Wisconsin, Michigan and Ontario...
. First eukaryoteEukaryoteA eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
s. - 1800 Ma: StatherianStatherianThe Statherian 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....
Period starts. SupercontinentSupercontinentIn geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
ColumbiaColumbia (supercontinent)Columbia, also known as Nuna and Hudsonland, was one of Earth's oldest supercontinents. It was first proposed by J.J.W. Rogers and M. Santosh and is thought to have existed approximately 1.8 to 1.5 billion years ago in the Paleoproterozoic Era. Zhao et al...
forms, one of whose fragments being NenaNena (supercontinent)Nena was an ancient minor supercontinent that consisted of the cratons of Arctica, Baltica, and East Antarctica. Forming about 1.8 billion years ago, the continent was part of the global supercontinent, Columbia. Nena is an acronym that derives from Northern Europe and North...
. Oldest ergErg (landform)An erg is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The term takes its name from the Arabic word ʿarq , meaning "dune field"...
s develop on several cratons
Mesoproterozoic
- 1600 Ma: Mesoproterozoic Era and CalymmianCalymmianThe Calymmian is the first geologic period in the Mesoproterozoic Era and lasted from 1600 Mya to 1400 Mya...
Period start. Platform coverPlatform coverIn geology, a platform cover is the sedimentary and volcanic deposits that lie on top of a craton....
s expand. - 1500 Ma: Supercontinent ColumbiaColumbia (supercontinent)Columbia, also known as Nuna and Hudsonland, was one of Earth's oldest supercontinents. It was first proposed by J.J.W. Rogers and M. Santosh and is thought to have existed approximately 1.8 to 1.5 billion years ago in the Paleoproterozoic Era. Zhao et al...
breaks up. First structurally complex eukaryoteEukaryoteA eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
s. - 1400 Ma: EctasianEctasianThe Ectasian is the second geologic period in the Mesoproterozoic Era and lasted from 1400 Mya ago to 1200 Mya...
Period starts. Platform coverPlatform coverIn geology, a platform cover is the sedimentary and volcanic deposits that lie on top of a craton....
s expand. StromatoliteStromatoliteStromatolites or stromatoliths are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria ....
diversity increases. - 1300 Ma: Grenville orogenyGrenville orogenyThe Grenville Orogeny was a long-lived Mesoproterozoic mountain-building event associated with the assembly of the supercontinent Rodinia. Its record is a prominent orogenic belt which spans a significant portion of the North American continent, from Labrador to Mexico, as well as to Scotland...
starts. - 1200 Ma: Red alga BangiomorphaBangiomorphaBangiomorpha pubescens is a red alga. It is the first known sexually reproducing organism. A multicellular fossil of Bangiomorpha pubescens was recovered from Arctic Canada that strongly resembles the modern red alga Bangia despite occurring in rocks dating to ....
pubescens, first known sexSexIn biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents...
ually reproducing organismOrganismIn biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
. StenianStenianThe Stenian 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...
Period starts, during which supercontinent RodiniaRodiniaIn geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era...
comes together. - 1100 Ma: First dinoflagellateDinoflagellateThe dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
. - 1000 Ma: Grenville orogenyGrenville orogenyThe Grenville Orogeny was a long-lived Mesoproterozoic mountain-building event associated with the assembly of the supercontinent Rodinia. Its record is a prominent orogenic belt which spans a significant portion of the North American continent, from Labrador to Mexico, as well as to Scotland...
ends.
Neoproterozoic
- 1000 Ma: Neoproterozoic Era and TonianTonianThe Tonian is the first geologic period in the Neoproterozoic Era and lasted from 1000 Mya to 850 Mya...
Period starts. First radiation of acritarchAcritarchAcritarchs are small organic fossils, present from approximately to the present. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion.-Definition:In general, any small, non-acid soluble Acritarchs are small organic fossils, present from...
s. RodiniaRodiniaIn geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era...
starts to break up. First vaucherian algae. - 850 Ma: CryogenianCryogenianThe Cryogenian is a geologic period that lasted from . It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran...
Period starts, during which Earth freezes over (Snowball EarthSnowball EarthThe Snowball Earth hypothesis posits that the Earth's surface became entirely or nearly entirely frozen at least once, some time earlier than 650 Ma . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical...
or Slushball Earth) at least 3 times. - 750 Ma: Sturtian glaciation starts. RodiniaRodiniaIn geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era...
splits. Beginning of a possible Snowball EarthSnowball EarthThe Snowball Earth hypothesis posits that the Earth's surface became entirely or nearly entirely frozen at least once, some time earlier than 650 Ma . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical...
ice age. First protozoaProtozoaProtozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
. - 700 Ma: WormWormThe term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
impressions in ChinaChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. - 685 Ma: VarangerVarangerVaranger may refer to:*Varanger Peninsula of Norway*Cryogenian...
glaciation begins. - 635 Ma: VarangerVarangerVaranger may refer to:*Varanger Peninsula of Norway*Cryogenian...
glaciation ends. - 635 Ma: EdiacaranEdiacaranThe Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...
period begins. - 600 Ma: Pan-African orogenyPan-African orogenyThe Pan-African orogeny was a series of major Neoproterozoic orogenic events which related to the formation of the supercontinents Gondwana and Pannotia about 600 million years ago....
. SupercontinentSupercontinentIn geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
PannotiaPannotiaPannotia, first described by Ian W. D. Dalziel in 1997, is a hypothetical supercontinent that existed from the Pan-African orogeny about six hundred million years ago to the end of the Precambrian about five hundred and fifty million years ago. It is also known as the Vendian supercontinent...
forms. - 575 Ma: First Ediacaran-type fossils.
- 560 Ma: Trace fossilTrace fossilTrace fossils, also called ichnofossils , are geological records of biological activity. Trace fossils may be impressions made on the substrate by an organism: for example, burrows, borings , urolites , footprints and feeding marks, and root cavities...
s, e.g., wormWormThe term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
burrowBurrowA burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
s, and small bilaterally symmetrical animals. Earliest arthropodArthropodAn arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s. Earliest fungi. - 555 Ma: The first possible mollusk KimberellaKimberellaKimberella is a monospecific genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the molluscs, although its affinity with this group is contentious.Specimens were first found in...
appears. - 550 Ma: First possible comb-jellies, sponges, corals, and anemones.
- 544 Ma: The small shelly faunaSmall shelly faunaThe small shelly fauna or small shelly fossils, abbreviated to SSF, are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambrian period. They are very diverse, and there is no formal definition of...
first appears.
Paleozoic
- 542 Ma: beginning of the CambrianCambrianThe Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
period, the Paleozoic Era and the PhanerozoicPhanerozoicThe Phanerozoic Eon is the current eon in the geologic timescale, and the one during which abundant animal life has existed. It covers roughly 542 million years and goes back to the time when diverse hard-shelled animals first appeared...
(current) Eon. End of the Ediacaran Period, the ProterozoicProterozoicThe Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
Eon and the PrecambrianPrecambrianThe Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
Supereon. Time since the Cambrian explosionCambrian explosionThe Cambrian explosion or Cambrian radiation was the relatively rapid appearance, around , of most major phyla, as demonstrated in the fossil record, accompanied by major diversification of other organisms, including animals, phytoplankton, and calcimicrobes...
the emergence of most forms of complex life, including vertebrateVertebrateVertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s (fishFishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
), arthropodArthropodAn arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, echinodermEchinodermEchinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s and molluscs. PannotiaPannotiaPannotia, first described by Ian W. D. Dalziel in 1997, is a hypothetical supercontinent that existed from the Pan-African orogeny about six hundred million years ago to the end of the Precambrian about five hundred and fifty million years ago. It is also known as the Vendian supercontinent...
breaks up into several smaller continents: LaurentiaLaurentiaLaurentia is a large area of continental craton, which forms the ancient geological core of the North American continent...
, BalticaBalticaBaltica is a name applied by geologists to a late-Proterozoic, early-Palaeozoic continent that now includes the East European craton of northwestern Eurasia. Baltica was created as an entity not earlier than 1.8 billion years ago. Before this time, the three segments/continents that now comprise...
and GondwanaGondwanaIn paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
. - 530 Ma: Possible early land animals.
- 525 Ma: First graptoliteGraptoliteGraptolithina is a class in the animal phylum Hemichordata, the members of which are known as Graptolites. Graptolites are fossil colonial animals known chiefly from the Upper Cambrian through the Lower Carboniferous...
s. - 510 Ma: First cephalopodCephalopodA cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s and chitonChitonChitons are small to large, primitive marine molluscs in the class Polyplacophora.There are 900 to 1,000 extant species of chitons in the class, which was formerly known as Amphineura....
s. - 505 Ma: Fossilization of the Burgess ShaleBurgess ShaleThe Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...
. - 500 Ma: Beginning of the OrdovicianOrdovicianThe Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
and the end of the CambrianCambrianThe Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
period. - 485 Ma: First jawless fishes.
- 450 Ma: Plants and arthropodArthropodAn arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s colonize the land. SharkSharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
s evolve. - 440 Ma: First agnathan fish.
- 435 Ma: Beginning of the SilurianSilurianThe Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
and the end of the OrdovicianOrdovicianThe Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
period. - 420 Ma: First creature took a breath of airLungThe lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
. First ray-finned fish and land scorpions. - 410 Ma: First toothed fish and nautiloidNautiloidNautiloids are a large and diverse group of marine cephalopods belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living Nautilus. Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, and...
s. - 400 Ma: Beginning of the DevonianDevonianThe Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
and end of the SilurianSilurianThe Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
period. First insectInsectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. - 395 Ma: First of many modern groups, including tetrapodTetrapodTetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
s. - 360 Ma: First crabCrabTrue crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s and fernFernA fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s. - 350 Ma: First large sharks, ratfish and hagfishHagfishHagfish, the clade Myxini , are eel-shaped slime-producing marine animals . They are the only living animals that have a skull but not a vertebral column. Along with lampreys, hagfish are jawless and are living fossils whose next nearest relatives include all vertebrates...
. - 340 Ma: Beginning of the CarboniferousCarboniferousThe Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
and the end of Devonian period. AmphibianAmphibianAmphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s diversify. - 330 Ma: First amnioteAmnioteThe amniotes are a group of tetrapods that have a terrestrially adapted egg. They include synapsids and sauropsids , as well as their fossil ancestors. Amniote embryos, whether laid as eggs or carried by the female, are protected and aided by several extensive membranes...
s evolve. - 320 Ma: First synapsidSynapsidSynapsids are a group of animals that includes mammals and everything more closely related to mammals than to other living amniotes. They are easily separated from other amniotes by having an opening low in the skull roof behind each eye, leaving a bony arch beneath each, accounting for their name...
s evolve. - 315 Ma: The evolution of the first reptiles.
- 305 Ma: First diapsidDiapsidDiapsids are a group of reptiles that developed two holes in each side of their skulls, about 300 million years ago during the late Carboniferous period. Living diapsids are extremely diverse, and include all crocodiles, lizards, snakes, and tuatara...
s evolve. - 280 Ma: End of CarboniferousCarboniferousThe Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
and beginning of Permian Period. By this time, all continents have fused into the supercontinentSupercontinentIn geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
of PangaeaPangaeaPangaea, Pangæa, or Pangea is hypothesized as a supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration....
. BeetleBeetleColeoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s evolve. Seed plants and conifers diversify along with temnospondyls and pelycosaurPelycosaurThe pelycosaurs are an informal grouping composed of basal or primitive Late Paleozoic synapsid amniotes. Some species were quite large and could grow up to 3 meters or more, although most species were much smaller...
s. - 275 Ma: First therapsids evolve.
- 251.4 Ma: Permian mass extinction. End of PermianPermianThe PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
Period and of the Palaeozoic Era. Beginning of TriassicTriassicThe Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
Period, the Mesozoic era and of the age of the dinosaurs.
Mesozoic
- 251.4 Ma: Mesozoic era and Triassic period begin. Mesozoic Marine RevolutionMesozoic Marine RevolutionThe Mesozoic marine revolution was a fundamental restructuring of marine ecosystems during the Mesozoic era, particularly in the Jurassic and Cretaceous, caused by increased predation pressure....
begins. - 245 Ma: First ichthyosaurIchthyosaurIchthyosaurs were giant marine reptiles that resembled fish and dolphins...
s. - 240 Ma: CynodontCynodontCynodontia or cynodonts are a taxon of therapsids which first appeared in the Late Permian and were eventually distributed throughout all seven continents by the Early Triassic . This clade includes modern mammals and their extinct close relatives. They were one of the most diverse groups of...
s and rhynchosaurRhynchosaurRhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...
s diversify. - 225 Ma: First dinosaurDinosaurDinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s and teleosti evolve. - 220 Ma: First crocodilians and fliesFließFließ is a municipality in the Landeck district and is located5 km south of Landeck on the upper course of the Inn River. It has 9 hamlets and was already populated at the roman age; the village itself was founded around the 6th century. After a conflagration in 1933 Fließ was restored more...
. - 215 Ma: First turtles. Long-necked sauropod dinosaurs and CoelophysisCoelophysisCoelophysis , meaning "hollow form" in reference to its hollow bones , is one of the earliest known genera of dinosaur...
, one of the earliest theropod dinosaurs, evolve. First mammalMammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s. - 195 Ma: end of Triassic and beginning of JurassicJurassicThe Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
Period. The largest dinosaurs, such as DiplodocusDiplodocusDiplodocus , or )is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones...
and BrachiosaurusBrachiosaurusBrachiosaurus is a genus of sauropod dinosaur from the Jurassic Morrison Formation of North America. It was first described by Elmer S. Riggs in 1903 from fossils found in the Grand River Canyon of western Colorado, in the United States. Riggs named the dinosaur Brachiosaurus altithorax,...
evolve during this time, as do the carnosaurs; large, bipedal predatory dinosaurs such as AllosaurusAllosaurusAllosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period . The name Allosaurus means "different lizard". It is derived from the Greek /allos and /sauros...
. First specialized pterosaurPterosaurPterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
s and sauropods. Ornithischians diversify. - 190 Ma: PliosaurPliosaurPliosauroidea is an extinct clade of marine reptiles. Pliosauroids, also commonly known as pliosaurs, are known from the Jurassic and Cretaceous Periods. The pliosauroids were short-necked plesiosaurs with large heads and massive toothed jaws. These swimming reptiles were not dinosaurs but distant...
s evolve, along with many groups of primitive sea invertebrates. - 180 Ma: PangaeaPangaeaPangaea, Pangæa, or Pangea is hypothesized as a supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration....
splits into two major continents: LaurasiaLaurasiaIn paleogeography, Laurasia was the northernmost of two supercontinents that formed part of the Pangaea supercontinent from approximately...
in the north and GondwanaGondwanaIn paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
in the south. - 176 Ma: First stegosaurs.
- 170 Ma: First salamanderSalamanderSalamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...
s and newtNewtA newt is an aquatic amphibian of the family Salamandridae, although not all aquatic salamanders are considered newts. Newts are classified in the subfamily Pleurodelinae of the family Salamandridae, and are found in North America, Europe and Asia...
s evolve. CynodontCynodontCynodontia or cynodonts are a taxon of therapsids which first appeared in the Late Permian and were eventually distributed throughout all seven continents by the Early Triassic . This clade includes modern mammals and their extinct close relatives. They were one of the most diverse groups of...
s go extinct. - 165 Ma: First stingrayStingrayThe stingrays are a group of rays, which are cartilaginous fishes related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes, and consist of eight families: Hexatrygonidae , Plesiobatidae , Urolophidae , Urotrygonidae , Dasyatidae , Potamotrygonidae The...
s. - 161 Ma: First ceratopsians.
- 155 Ma: First birdBirdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s and triconodonts. Stegosaurs and theropods diversify. - 135 Ma: End of JurassicJurassicThe Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and beginning of CretaceousCretaceousThe Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
Period. - 130 Ma: LaurasiaLaurasiaIn paleogeography, Laurasia was the northernmost of two supercontinents that formed part of the Pangaea supercontinent from approximately...
and GondwanaGondwanaIn paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
begin to split apart as the Atlantic OceanAtlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
forms. First flowering plantFlowering plantThe flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s. - 115 Ma: First monotremeMonotremeMonotremes are mammals that lay eggs instead of giving birth to live young like marsupials and placental mammals...
s. - 110 Ma: First hesperornithesHesperornithesHesperornithes is an extinct and highly specialized clade of Cretaceous toothed birds. Hesperornithine birds, apparently limited to former aquatic habitats in the Northern Hemisphere, include genera such as Hesperornis, Parahesperornis, Baptornis, Enaliornis, and probably Potamornis, all...
. - 106 Ma: SpinosaurusSpinosaurusSpinosaurus is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. This genus was first known from Egyptian remains discovered in 1912 and described by German...
evolves. - 100 Ma: First beeBeeBees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s. - 90 Ma: the Indian subcontinentIndian subcontinentThe Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
splits from GondwanaGondwanaIn paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
, becoming an island continentContinentA continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents—they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia.Plate tectonics is...
. IchthyosaurIchthyosaurIchthyosaurs were giant marine reptiles that resembled fish and dolphins...
s go extinct. SnakeSnakeSnakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s and tickTickTicks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s evolve. - 80 Ma: Australia splits from Antarctica. First antAntAnts are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s. - 70 Ma: Multituberculates diversify.
- 68 Ma: Tyrannosaurus Rex evolves.
- 65 Ma: Cretaceous-Tertiary extinction eventCretaceous-Tertiary extinction eventThe Cretaceous–Paleogene extinction event, formerly named and still commonly referred to as the Cretaceous-Tertiary extinction event, occurred approximately 65.5 million years ago at the end of the Maastrichtian age of the Cretaceous period. It was a large-scale mass extinction of animal and plant...
at the end of the CretaceousCretaceousThe Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period marks the end of the MesozoicMesozoicThe Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
era and the age of the dinosaurs; start of the PaleogenePaleogeneThe Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
period and the current CenozoicCenozoicThe Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
era.
Cenozoic
- 63 Ma: First creodonts.
- 60 Ma: Evolution of the first primates and miacids. Flightless birds diversify.
- 56 Ma: GastornisGastornisGastornis is an extinct genus of large flightless bird that lived during the late Paleocene and Eocene epochs of the Cenozoic. It was named in 1855, after Gaston Planté, who had discovered the first fossils in Argile Plastique formation deposits at Meudon near Paris...
evolves. - 55 Ma: the island of the Indian subcontinentIndian subcontinentThe Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
collides with Asia, thrusting up the HimalayasHimalayasThe Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
and the Tibetan PlateauTibetan PlateauThe Tibetan Plateau , also known as the Qinghai–Tibetan Plateau is a vast, elevated plateau in Central Asia covering most of the Tibet Autonomous Region and Qinghai, in addition to smaller portions of western Sichuan, southwestern Gansu, and northern Yunnan in Western China and Ladakh in...
. Many modern bird groups appear. First whaleWhaleWhale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
ancestors. First rodentRodentRodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s, lagomorphs, armadilloArmadilloArmadillos are New World placental mammals, known for having a leathery armor shell. Dasypodidae is the only surviving family in the order Cingulata, part of the superorder Xenarthra along with the anteaters and sloths. The word armadillo is Spanish for "little armored one"...
s, sirenians, proboscideans, perissodactyls, artiodactyls, and mako sharks. Angiosperms diversify. - 52 Ma: First batBatBats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s. - 50 Ma: Africa collides with EurasiaEurasiaEurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
, closing the Tethys Sea. Divergence of cat and dog ancestors. Primates diversify. Brontotheres, tapirTapirA Tapir is a large browsing mammal, similar in shape to a pig, with a short, prehensile snout. Tapirs inhabit jungle and forest regions of South America, Central America, and Southeast Asia. There are four species of Tapirs: the Brazilian Tapir, the Malayan Tapir, Baird's Tapir and the Mountain...
s, rhinoRhinoRhino is a colloquial abbreviation of rhinoceros"Rhino" may also refer to:-Entertainment:* Rhino , a character from the Marvel Comics universe and sometime-foe of Spider-Man...
s, and camelCamelA camel is an even-toed ungulate within the genus Camelus, bearing distinctive fatty deposits known as humps on its back. There are two species of camels: the dromedary or Arabian camel has a single hump, and the bactrian has two humps. Dromedaries are native to the dry desert areas of West Asia,...
s evolve. - 49 Ma: WhaleWhaleWhale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s return to the water. - 40 Ma: Age of the CatarrhiniCatarrhiniCatarrhini is one of the two subdivisions of the higher primates . It contains the Old World monkeys and the apes, which in turn are further divided into the lesser apes or gibbons and the great apes, consisting of the orangutans, gorillas, chimpanzees, bonobos, and humans...
parvorder; first caninesCanidaeCanidae is the biological family of carnivorous and omnivorous mammals that includes wolves, foxes, jackals, coyotes, and domestic dogs. A member of this family is called a canid . The Canidae family is divided into two tribes: Canini and Vulpini...
evolve. LepidopteraLepidopteraLepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
n insects become recognizable. GastornisGastornisGastornis is an extinct genus of large flightless bird that lived during the late Paleocene and Eocene epochs of the Cenozoic. It was named in 1855, after Gaston Planté, who had discovered the first fossils in Argile Plastique formation deposits at Meudon near Paris...
goes extinct. BasilosaurusBasilosaurusBasilosaurus is a genus of cetacean that lived from in the Late Eocene. Its fossilized remains were first discovered in the southern United States . The American fossils were initially believed to be some sort of reptile, hence the suffix -"saurus", but later found to be a marine mammal...
evolves. - 37 Ma: First Nimravids.
- 36 Ma: End of EoceneEoceneThe Eocene Epoch, lasting from about 56 to 34 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 Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
, start of OligoceneOligoceneThe Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
epoch. - 35 Ma: GrasslandGrasslandGrasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s first appear. Glyptodonts, ground slothGround slothGround sloths are a diverse group of extinct sloths, in the mammalian superorder Xenarthra. Their most recent survivors lived in the Antilles, where it has been proposed they may have survived until 1550 CE; however, the youngest AMS radiocarbon date reported is 4190 BP, calibrated to c. 4700 BP...
s, peccaries, dogs, eagles, and hawks evolve. - 34 Ma: CatFelidaeFelidae is the biological family of the cats; a member of this family is called a felid. Felids are the strictest carnivores of the thirteen terrestrial families in the order Carnivora, although the three families of marine mammals comprising the superfamily pinnipedia are as carnivorous as the...
s evolve. - 33 Ma: First thylacinid marsupials evolve.
- 30 Ma: Brontotheres go extinct. Pigs evolve. South AmericaSouth AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
separates from Antarctica, becoming an island continent. - 28 Ma: ParaceratheriumParaceratheriumParaceratherium, also commonly known as Indricotherium or Baluchitherium , is an extinct genus of gigantic hornless rhinoceros-like mammals of the family Hyracodontidae, endemic to Eurasia and Asia during the Eocene to Oligocene 37.2—23.030 Mya, existing for approximately...
evolves. - 26 Ma: Emergence of the first true elephantsProboscideaProboscidea is a taxonomic order containing one living family, Elephantidae, and several extinct families. This order was first described by J. Illiger in 1881 and encompasses the trunked mammals...
. - 25 Ma: First deer.
- 24 Ma: NeogeneNeogeneThe Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...
period and MioceneMioceneThe Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
epoch begin - 20 Ma: Giraffes and giant anteaterGiant AnteaterThe Giant Anteater, Myrmecophaga tridactyla, is the largest species of anteater. It is the only species in the genus Myrmecophaga. It is found in Central and South America from Honduras to northern Argentina...
s evolve. - 18-12 Ma: estimated age of the HominidaeHominidaeThe Hominidae or include them .), as the term is used here, form a taxonomic family, including four extant genera: chimpanzees , gorillas , humans , and orangutans ....
/Hylobatidae (great apes vs. gibbons) split. - 15 Ma: First mastodonMastodonMastodons were large tusked mammal species of the extinct genus Mammut which inhabited Asia, Africa, Europe, North America and Central America from the Oligocene through Pleistocene, 33.9 mya to 11,000 years ago. The American mastodon is the most recent and best known species of the group...
s, bovidBovidA bovid is any of almost 140 species of cloven-hoofed ruminant mammal at least the males of which bear characteristic unbranching horns covered in a permanent sheath of keratin....
s, and kangaroos. Australian megafauna diversify. - 10 Ma: Insects diversify. First large horses.
- 6.5 Ma: First members of the HomininiHomininiHominini is the tribe of Homininae that comprises Homo, and the two species of the genus Pan , their ancestors, and the extinct lineages of their common ancestor . Members of the tribe are called hominins...
tribe. - 6 Ma: AustralopithecineAustralopithecineThe term australopithecine refers generally to any species in the related genera Australopithecus or Paranthropus. These species occurred in the Plio-Pleistocene era, and were bipedal and dentally similar to humans, but with a brain size not much larger than modern apes, lacking the...
s diversify. - 5.4-6.3 Ma: Estimated age of the HomoHomo (genus)Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
/Pan (human vs. chimpanzee) split. - 5.5 Ma: Appearance of the genus ArdipithecusArdipithecusArdipithecus is a very early hominin genus. Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago ....
- 5 Ma: PliocenePlioceneThe Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
epoch begins. First tree sloths and hippopotami. First large vultures. Nimravids go extinct. - 4.8 Ma: The mammothMammothA mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...
appears. - 4.5 Ma: appearance of the genus AustralopithecusAustralopithecusAustralopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
- 3 Ma: Isthmus of PanamaIsthmus of PanamaThe Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
joins North and South America. Great American InterchangeGreat American InterchangeThe Great American Interchange was an important paleozoogeographic event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents...
. - 2.7 Ma: ParanthropusParanthropusThe robust australopithecines, members of the extinct hominin genus Paranthropus , were bipedal hominids that probably descended from the gracile australopithecine hominids...
evolve. - 2.6 Ma: current ice ageIce ageAn ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
begins - 2.5 Ma: start of the PleistocenePleistoceneThe Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
epoch and the current QuaternaryQuaternaryThe Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
period; emergence of the genus HomoHomo (genus)Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
. SmilodonSmilodonSmilodon , often called a saber-toothed cat or saber-toothed tiger, is an extinct genus of machairodonts. This saber-toothed cat was endemic to North America and South America, living from near the beginning through the very end of the Pleistocene epoch .-Etymology:The nickname "saber-tooth" refers...
, the best known of the sabre-toothed cats, appears.
Etymology of period names
| Period | Started | Root Root (linguistics) The root word is the primary lexical unit of a word, and of a word family , which carries the most significant aspects of semantic content and cannot be reduced into smaller constituents.... word | Meaning | Reason for name |
|---|---|---|---|---|
| Siderian Siderian The Siderian 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.... |
2500 Ma | Greek Greek language Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;... sidēros |
iron | ref. the banded iron formation Banded iron formation Banded iron formations are distinctive units of sedimentary rock that are almost always of Precambrian age. A typical BIF consists of repeated, thin layers of iron oxides, either magnetite or hematite , alternating with bands of iron-poor shale and chert... s |
| Rhyacian | 2300 Ma | Gk. rhyax | lava Lava Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at... flow |
much lava flowed |
| Orosirian Orosirian The Orosirian 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.... |
2050 Ma | Gk. oroseira | mountain range | much orogeny Orogeny Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts... in this period's latter half |
| Statherian Statherian The Statherian 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.... |
1800 Ma | Gk. statheros | steady | continents became stable craton Craton A craton is an old and stable part of the continental lithosphere. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates. They are characteristically composed of ancient crystalline basement rock, which may be covered by... s |
| Calymmian Calymmian The Calymmian is the first geologic period in the Mesoproterozoic Era and lasted from 1600 Mya to 1400 Mya... |
1600 Ma | Gk. calymma | cover | platform cover Platform cover In geology, a platform cover is the sedimentary and volcanic deposits that lie on top of a craton.... s developed or expanded |
| Ectasian Ectasian The Ectasian is the second geologic period in the Mesoproterozoic Era and lasted from 1400 Mya ago to 1200 Mya... |
1400 Ma | Gk. ectasis | stretch | platform cover Platform cover In geology, a platform cover is the sedimentary and volcanic deposits that lie on top of a craton.... s expanded |
| Stenian Stenian The Stenian 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... |
1200 Ma | Gk. stenos | narrow | much orogeny, which survives as narrow metamorphic Metamorphic rock Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change... belts |
| Tonian Tonian The Tonian is the first geologic period in the Neoproterozoic Era and lasted from 1000 Mya to 850 Mya... |
1000 Ma | Gk. tonos | stretch | The continental crust stretched as Rodinia Rodinia In geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era... broke up |
| Cryogenian Cryogenian The Cryogenian is a geologic period that lasted from . It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran... |
850 Ma |
Gk. cryogenicos | cold-making | In this period all the Earth froze over |
| Ediacaran Ediacaran The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon... |
635 Ma | Ediacara Hills Ediacara Hills Ediacara Hills are a range of low hills in the northern part of the Flinders Ranges of South Australia, around 650 km north of Adelaide. The area has many old copper and silver mines from mining activity in the late 19th century... |
place in Australia where the Ediacaran biota fossils were found | |
| Cambrian Cambrian The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's... |
542 Ma | Latin Cambria | Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
ref. to the place in Great Britain Great Britain Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles... where Cambrian rocks are best exposed |
| Ordovician Ordovician The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period... |
488 Ma | Celtic Ordovices Ordovices The Ordovices were one of the Celtic tribes living in Great Britain, before the Roman invasion of Britain. Its tribal lands were located in present day Wales and England between the Silures to the south and the Deceangli to the north-east... |
Tribe in north Wales, where the rocks were first identified | |
| Silurian Silurian The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the... |
444 Ma | Ctc. Silures Silures The Silures were a powerful and warlike tribe of ancient Britain, occupying approximately the counties of Monmouthshire, Breconshire and Glamorganshire of present day South Wales; and possibly Gloucestershire and Herefordshire of present day England... |
Tribe in south Wales, where the rocks were first identified | |
| Devonian Devonian The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya... |
416 Ma | Devon Devon Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with... |
County in England in which rocks from this period were first identified | |
| Carboniferous Carboniferous The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"... |
359 Ma | Lt. carbo | coal | Global coal beds were laid in this period |
| Permian Permian The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian... |
299 Ma | Perm Krai Perm Krai Perm Krai is a federal subject of Russia that came into existence on December 1, 2005 as a result of the 2004 referendum on the merger of Perm Oblast and Komi-Permyak Autonomous Okrug. The city of Perm became the administrative center of the new federal subject... |
Region in Russia Russia Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects... where rocks from this period were first identified |
|
| Triassic Triassic The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events... |
250 Ma | Lt. trias | triad | In Germany this period forms three distinct layers |
| Jurassic Jurassic The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by... |
200 Ma | Jura Mountains Jura mountains The Jura Mountains are a small mountain range located north of the Alps, separating the Rhine and Rhone rivers and forming part of the watershed of each... |
Mountain range in the Alps Alps The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west.... in which rocks from this period were first identified |
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| Cretaceous Cretaceous The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the... |
146 Ma | Lt. creta | chalk | More chalk formed in this period than any other |
| Paleogene Paleogene The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era... |
65 Ma | Gk. palaiogenos | "ancient born" | |
| Neogene Neogene The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago... |
23 Ma | Gk. neogenos | "new born" | |
| Quaternary Quaternary The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present... |
2.6 Ma | Lt. quaternarius | "fourth" | This was initially deemed the "fourth" period after the now-obsolete "primary", "secondary" and "tertiary" periods. |
See also
- Timeline of the far futureTimeline of the far futureWhile predictions of the future can never be absolutely certain, this list of predictions follows from present scientific understanding and models...
- Detailed logarithmic timelineDetailed logarithmic timelineThis timeline allows one to see the whole history of the universe, the Earth, and mankind in one table.Each row is defined in years ago, that is, years before the present date, with the earliest times at the top of the chart...
- Terasecond and longerTerasecond and longerA terasecond is 1 trillion seconds, or roughly 31,700 years. This page lists time-spans above 1 terasecond. 1 thousand teraseconds is called a petasecond...