The Eocene epoch (55. The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other 8 ± 0. 2 - 33. 9 ± 0. 1 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. Annum is one form of the Latin noun meaning Year, not a form normally used for derivatives in modern languages the accusative singular The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other The Paleogene (alternatively Palaeogene) is a geologic period and system that began 65 The Cenozoic (also Caenozoic or Cainozoic) Era (ˌsiːnəˈzoʊɪk/ /ˌsɛn- (meaning "new life" ( Greek ( kainos) "new" The Eocene spans the time from the end of the Paleocene epoch to the beginning of the Oligocene epoch. The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65 The Oligocene is a geologic epoch of the Paleogene period and extends from about 33 The start of the Eocene is marked by the emergence of the first modern mammals. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The end is set at a major extinction event called Grande Coupure (the "Great Break" in continuity), which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. An extinction event (also known as mass extinction; extinction-level event, ELE is a sharp decrease in the number of Species in a relatively short period The Popigai crater in Siberia, Russia is tied with Manicouagan Reservoir as the 4th largest Impact crater on Earth. The Chesapeake Bay impact crater was formed by a Bolide that impacted the eastern shore of North America about 35 As with other geologic periods, the strata that define the start and end of the epoch are well identified,^[1] though their exact dates are slightly uncertain. In Geology and related fields a stratum (plural strata) is a layer of rock or Soil with internally consistent characteristics that distinguishes

The name Eocene comes from the Greek ἠώς (eos, dawn) and καινός (kainos, new) and refers to the "dawn" of modern ('new') mammalian fauna that appeared during the epoch. The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c Dawn refers to the Twilight before Sunrise. It is recognized by the presence of weak sunlight while the sun itself is still below the horizon Fauna is all of the Animal life of any particular region or time

Paleogene period
Paleocene epoch	Eocene epoch	Oligocene epoch
Danian | Selandian Thanetian	Ypresian | Lutetian Bartonian | Priabonian	Rupelian | Chattian

Contents 1 Subdivisions 2 Climate 3 Paleogeography 4 Flora 5 Fauna 5.1 Oceans 6 Grande Coupure 7 See also 8 Notes 9 References 10 External links

Subdivisions

The Eocene epoch is usually broken into Early and Late, or - more usually - Early, Middle, and Late subdivisions. The Paleogene (alternatively Palaeogene) is a geologic period and system that began 65 The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65 The Oligocene is a geologic epoch of the Paleogene period and extends from about 33 The Danian (also known as the Montian) is the first stage of the Paleocene Epoch, making up the Early Paleocene sub-epoch Selandian or Middle Paleocene is a stage of the Paleocene Epoch. The Thanetian (also known as the Landenian or Heersian) is the last stage of the Paleocene Epoch, corresponding to the Late Paleocene The Ypresian is the first stage of the Eocene Epoch and usually corresponds to the Early Eocene subepoch though sometimes the Lutetian The Lutetian is a stage of the Eocene Epoch. It spans the time between 48 The Bartonian (also known as the Auversian) is a stage of the middle Eocene Epoch. The Priabonian (also known as Jacksonian or Runangan) is the final stage of the Eocene Epoch. The Rupelian (also known as Stampian, Tongrian, Latdorfian, Vicksburgian, or Early Oligocene) is the first of two stages The Chattian (also known as Chickasawhayan or Late Oligocene) is the second and final of two stages of the Oligocene Epoch. The corresponding rocks are referred to as Lower, Middle, and Upper Eocene. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere The Faunal stages from youngest to oldest are:

Priabonian	(37. The Priabonian (also known as Jacksonian or Runangan) is the final stage of the Eocene Epoch. 2 ± 0. 1 – 33. 9 ± 0. 1 Ma)
Bartonian	(40. The Bartonian (also known as the Auversian) is a stage of the middle Eocene Epoch. 4 ± 0. 2 – 37. 2 ± 0. 1 Ma)
Lutetian	(48. The Lutetian is a stage of the Eocene Epoch. It spans the time between 48 6 ± 0. 2 – 40. 4 ± 0. 2 Ma)
Ypresian	(55. The Ypresian is the first stage of the Eocene Epoch and usually corresponds to the Early Eocene subepoch though sometimes the Lutetian 8 ± 0. 2 – 48. 6 ± 0. 2 Ma)

The Ypresian and occasionally the Lutetian constitute the Lower, the Priabonian and sometimes the Bartonian the Upper subsection; alternatively, the Lutetian and Bartonian are united as the Middle Eocene.

Climate

Marking the start of the Eocene, Earth heated up in one of the most rapid (in geologic terms) and extreme global warming events recorded in geologic history, called the Paleocene-Eocene Thermal Maximum or Initial Eocene Thermal Maximum (PETM or IETM). EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Global warming is the increase in the average measured temperature of the The Paleocene /Eocene boundary, was marked by the most rapid and significant climatic disturbance of the Cenozoic Era. This was an episode of rapid and intense warming (up to 7°C at high latitudes) that lasted less than 100,000 years ^[2]. The Celsius Temperature scale was previously known as the centigrade scale. Latitude, usually denoted symbolically by the Greek letter phi ( Φ) gives the location of a place on Earth (or other planetary body north or south of the The Thermal Maximum provoked a sharp extinction event that distinguishes Eocene fauna from the ecosystems of the Paleocene. An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical (

The Eocene global climate was perhaps the most homogeneous of the Cenozoic; the temperature gradient from equator to pole was only half that of today's, and deep ocean currents were exceptionally warm. Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of The equator (sometimes referred to colloquially as "the Line") is the intersection of the Earth 's surface with the plane perpendicular to the A geographical pole, or geographic pole, is either of two fixed points on the surface of a spinning body or Planet, at 90 degrees from the Equator, based An ocean current is continuous directed movement of Ocean water. ^[3] The polar regions were much warmer than today, perhaps as mild as the modern-day Pacific Northwest; temperate forests extended right to the poles, while rainy tropical climates extended as far north as 45°. Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The Pacific Northwest is a region in the northwest of North America (the term refers to the land not the ocean The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 The difference was greatest in the temperate latitudes; the climate in the tropics however, was probably similar to today's. ^[4]

Climates remained warm through the rest of the Eocene, although slow global cooling triggered by the Azolla event, which eventually led to the Pleistocene glaciations, started as ocean currents around Antarctica formed. Global cooling in general can refer to an overall cooling of the Earth. The Azolla event occurred in the middle Eocene period around, when blooms of the freshwater Fern Azolla occurred in the Arctic Ocean "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period.

Paleogeography

During the Eocene, the continents continued to drift toward their present positions. A continent is one of several large Landmasses on Earth. They are generally identified by Convention rather than any strict criteria with seven regions Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere

At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents mixed with colder Antarctic waters, distributing the heat around the planet and keeping global temperatures high. For a topic outline on this subject see List of basic Australia topics. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is But when Australia split from the southern continent around 45 mya, the warm equatorial currents were deflected away from Antarctica, and an isolated cold water channel developed between the two continents. The Antarctic region cooled down, and the ocean surrounding Antarctica began to freeze, sending cold water and icefloes north, reinforcing the cooling. Sea ice is formed from Ocean water that freezes Because the Oceans consist of Saltwater, this occurs at about -1

The northern supercontinent of Laurasia began to break up, as Europe, Greenland and North America drifted apart. In Geology, a supercontinent is a Landmass comprising more than one Continental core or Craton. Laurasia (lɔˈreɪʃiə lɔˈreɪʒə was a Supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic Greenland (Kalaallit Nunaat meaning "Land of the Greenlanders" Grønland is a self-governing Danish Province located between the

In western North America, mountain building started in the Eocene, and huge lakes formed in the high flat basins among uplifts, resulting in the deposition of the Green River Formation lagerstätte. Orogeny (Greek for "mountain generating" is the process of natural Mountain building and may be studied as a tectonic structural event as a geographical event and The Green River Formation is an Eocene geologic formation that records the sedimentation in a series of intermountain lakes A Lagerstätte ( German; literally place of storage; plural Lagerstätten) is a sedimentary deposit that exhibits extraordinary fossil

In Europe, the Tethys Sea finally vanished, while the uplift of the Alps isolated its final remnant, the Mediterranean, and created another shallow sea with island archipelagos to the north. The Tethys Ocean was a Mesozoic era Ocean that existed between the continents of Gondwana and Laurasia before the opening of the Indian An archipelago (ɑrkəˈpɛləgoʊ is a chain or cluster of Islands The word archipelago literally means "chief Sea " from Italian Though the North Atlantic was opening, a land connection appears to have remained between North America and Europe since the faunas of the two regions are very similar.

India continued its journey away from Africa and began its collision with Asia, folding the Himalayas into existence. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country

It is hypothesized that the Eocene hothouse world was caused by runaway global warming from released methane clathrates deep in the oceans. Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of Methane within its Crystal An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. The clathrates were buried beneath mud that was disturbed as the oceans warmed. A clathrate or clathrate compound or cage compound is a Chemical substance consisting of a lattice of one type of molecule trapping In computer gaming, a MUD ( Multi-User Dungeon, Domain or Dimension) is a multi-player computer game that combines elements of Methane (CH₄) has ten to twenty times the greenhouse gas effect of carbon dioxide (CO₂). Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the

Flora

At the beginning of the Eocene, the high temperatures and warm oceans created a moist, balmy environment, with forests spreading throughout the Earth from pole to pole. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature A forest is an area with a high density of Trees There are many definitions of a forest based on various criteria Apart from the driest deserts, Earth must have been entirely covered in forests. A desert is a Landscape or region that receives very little precipitation.

Polar forests were quite extensive. Fossils and even preserved remains of trees such as swamp cypress and dawn redwood from the Eocene have been found on Ellesmere Island in the Arctic. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Metasequoia ( Dawn Redwood) is a fast growing Tree genus in the conifer family Cupressaceae of which Metasequoia glyptostroboides Ellesmere Island is part of the Qikiqtaaluk Region of the Canadian territory of Nunavut. The Arctic is the Region around the Earth 's North Pole, opposite the Antarctic region around the South Pole. The preserved remains are not fossils, but actual pieces preserved in oxygen-poor water in the swampy forests of the time and then buried before they had the chance to decompose. Water is a common Chemical substance that is essential for the survival of all known forms of Life. A swamp is a Wetland featuring temporary or permanent inundation of large areas of land by shallow bodies of water Decomposition (or spoilage) refers to the break down of tissue of a formerly living Organism into simpler forms of matter Even at that time, Ellesmere Island was only a few degrees in latitude further south than it is today. Fossils of subtropical and even tropical trees and plants from the Eocene have also been found in Greenland and Alaska. The subtropics are the zones of the Earth immediately north and south of the tropic zone which is bounded by the Tropic of Cancer and the Tropic of Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent Tropical rainforests grew as far north as the Pacific Northwest and Europe. Tropical rainforests are generally found near the Equator. They are common in Asia, Australia, Africa, South America, Central

Palm trees were growing as far north as Alaska and northern Europe during the early Eocene, although they became less abundant as the climate cooled. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering Dawn redwoods were far more extensive as well.

Cooling began mid-period, and by the end of the Eocene continental interiors had begun to dry out, with forests thinning out considerably in some areas. The newly-evolved grasses were still confined to river banks and lake shores, and had not yet expanded into plains and savannas. Poaceae or Gramineae is a family in the Class Liliopsida of the flowering plants. "Riverine" redirects here For the use of that term in Maritime geography, see there A lake (from Latin lacus) is a Terrain feature (or Physical feature) a body of Liquid on the surface of a world that is localized to the In Geography, a plain is an area of land with relatively low relief — meaning that it is flat A savanna or savannah is a Tropical or Subtropical Grassland or Woodland Ecosystem.

The cooling also brought seasonal changes. A season is one of the major divisions of the Year, generally based on yearly periodic changes in Weather. Deciduous trees, better able to cope with large temperature changes, began to overtake evergreen tropical species. Botany Autumn leaf color. See --> In Botany and Horticulture, deciduous Plants, including In Botany, an Evergreen plant is a plant having leaves all year round By the end of the period, deciduous forests covered large parts of the northern continents, including North America, Eurasia and the Arctic, and rainforests held on only in equatorial South America, Africa, India and Australia. For the superstate in George Orwell 's novel see Nations of Nineteen Eighty-Four. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country

Antarctica, which began the Eocene fringed with a warm temperate to sub-tropical rainforest, became much colder as the period progressed; the heat-loving tropical flora was wiped out, and by the beginning of the Oligocene, the continent hosted deciduous forests and vast stretches of tundra. In Botany, flora ( Plural: floras or florae has two meanings The first meaning flora of an area or of time period, refers to all In physical Geography, tundra is an area where the Tree growth is hindered by low temperatures and short growing seasons

Fauna

The oldest known fossils of most of the modern mammal orders appear within a brief period during the early Eocene. Mesonyx ("middle claw" is the Type genus of the family Mesonychidae, the type family of the Order Mesonychia A carnivore (ˈkɑrnɪvɔər meaning 'meat eater' ( Latin carne meaning 'flesh' and vorare meaning 'to devour' is any animal with a diet consisting Ungulates (meaning roughly "being Hoofed quot or "hoofed animal" are several groups of Mammals most of which use the tips of their toes usually FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. At the beginning of the Eocene, several new mammal groups arrived in North America. These modern mammals, like artiodactyls, perissodactyls and primates, had features like long, thin legs, feet and hands capable of grasping, as well as differentiated teeth adapted for chewing. The even-toed ungulates form the Mammal order Artiodactyla. They are Ungulates whose weight is borne (if they have more than two toes about The odd-toed ungulates are browsing and Grazing Mammals which compose the order Perissodactyla. A primate is a member of the biological order Primates ( Latin: "prime first rank" the group that contains Lemurs the Aye-aye A leg is a limb on an Animal 's Body that supports the rest of the animal above the ground between the Ankle and the Hip and is used for The foot is an Anatomical structure found in many Animals It is the terminal portion of a limb which bears weight and allows Locomotion. The hands ( med / lat: manus pl manūs are the two intricate prehensile multi- Fingered body parts normally located at the end of each arm of a Dwarf forms reigned. DWARF is a widely used standardized Debugging data format. DWARF was originally designed along with ELF, although it is independent of Object file All the members of the new mammal orders were small, under 10 kg; based on comparisons of tooth size, Eocene mammals were only 60% of the size of the primitive Paleocene mammals that preceded them. They were also smaller than the mammals that followed them. It is assumed that the hot Eocene temperatures favored smaller animals that were better able to manage the heat.

Both groups of modern ungulates (hoofed animals) became prevalent because of a major radiation between Europe and North America; along with carnivourous ungulates like Mesonyx. Ungulates (meaning roughly "being Hoofed quot or "hoofed animal" are several groups of Mammals most of which use the tips of their toes usually Mesonyx ("middle claw" is the Type genus of the family Mesonychidae, the type family of the Order Mesonychia Early forms of many other modern mammalian orders appeared, including bats, proboscidians, primates, rodents and marsupials. Proboscidea is an order containing only one family of living animals Elephantidae the Elephants with three living Species ( African Bush Rodentia is an order of Mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must Marsupials are an Infraclass of Mammals characterized by a distinctive pouch (called the marsupium) in which females carry their young through Older primitive forms of mammals declined in variety and importance. Important Eocene land fauna fossil remains have been found in western North America, Europe, Patagonia, Egypt and southeast Asia. Llao LLaojpg|thumb|250px| Lake Nahuel Huapi, near Bariloche, Argentina This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. Marine fauna are best known from South Asia and the southeast United States. The US Southeast is the eastern portion of the Southern United States, but the Census Bureau does not provide a standard definition of a "Southeast" region

Reptile fossils from this time, such as fossils of pythons and turtles, are abundant. Turtles are Reptiles of the Order Testudines (all living turtles belong to the Crown group Chelonia) most of

During the Eocene, plants and marine faunas became quite modern. Many modern bird orders first appeared in the Eocene. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs.

Some scientists believed that the first primates appeared around 55 Ma in the Ypresian era of the Eocene; however, the molecular clock and new paleontological finds indicate that the first primates appeared much earlier, around 90 Ma in the Cretaceous era. A scientist, in the broadest sense refers to any person that engages in a systematic activity to acquire Knowledge or an individual that engages in such practices The molecular clock (based on the molecular clock hypothesis ( MCH) is a technique in Molecular evolution to relate the divergence time of two Species Palaeontology redirects here For the Scientific journal, see Palaeontology (journal. The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of

Oceans

The Eocene oceans were warm and teeming with fish and other sea life. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two The first Carcharinid sharks appeared, as did early marine mammals, including Basilosaurus, an early species of whale that is thought to be descended from land animals, the hoofed predators called mesonychids, of which Mesonyx was a member. The ground sharks, order Carcharhiniformes, are the largest order of Sharks they are also called whaler sharks. Basilosaurus ("King Lizard" is a Genus of Cetacean that lived from 40 to 34 million years ago in the Eocene. Whales are marine mammals which are neither Dolphins (ie members of the families Delphinidae or Platanistoidae) nor Porpoises Orcas HoofRearHoovesjpg|thumb|200px|right|Rear hooves of a horse]] A hoof is the tip of a Toe of an Ungulate Mammal, strengthened by a thick horny ( Mesonychia ("Middle Claws quot are an extinct order of medium to large-sized carnivorous mammals that were closely related to Artiodactyls (even-toed Mesonyx ("middle claw" is the Type genus of the family Mesonychidae, the type family of the Order Mesonychia The first sirenians, relatives of the elephants, also appeared at this time. Not to be confused with order Sirenidae (aquatic salamanders For the Gothic metal band see Sirenia (band Sirenia Elephants ( family: Elephantidae) are large land Mammals of the order Proboscidea.

Grande Coupure

The Grande Coupure, or "great break" in continuity,^[5] with a major European turnover in mammalian fauna about 33. 5 Ma, marks the end of the last phase of Eocene assemblages, the Priabonian, and the arrival in Europe of Asian immigrants. The Priabonian (also known as Jacksonian or Runangan) is the final stage of the Eocene Epoch. The Grande Coupure is characterized by widespread extinctions and allopatric speciation in small isolated relict populations. Allopatric speciation, also known as geographic Speciation, is the phenomenon whereby biological populations are physically isolated by an extrinsic barrier The term relict is used to refer to surviving remnants of natural phenomena ^[6] It was given its name in 1910 by the Swiss palaeontologist Hans Georg Stehlin,^[7] to characterise the dramatic turnover of European mammalian fauna, which he placed at the Eocene-Oligocene boundary. Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation A comparable turnover in Asian fauna has since been called the "Mongolian Remodelling".

The Grande Coupure marks a break between endemic European faunas before the break and mixed faunas with a strong Asian component afterwards. Endemism is the Ecological state of being unique to a place Endemic species are not naturally found elsewhere J. J. Hooker and his team summarized the break:

"Pre-Grande Coupure faunas are dominated by the perissodact family Palaeotheriidae (distant horse relatives), six families of artiodactyls (cloven-hoofed mammals) (Anoplotheriidae, Xiphodontidae, Choeropotamidae, Cebochoeridae, Dichobunidae and Amphimerycidae), the rodent family Pseudosciuridae, the primate families Omomyidae and Adapidae, and the archontan family Nyctitheriidae. Palaeotheres are an extinct group of Herbivorous mammals related to Tapirs and Rhinoceros and probably ancestral to Horses They ranged across The horse ( Equus caballus) is a hoofed ( Ungulate) Mammal, one of eight living species of the family Equidae.

"Post-Grande Coupure faunas include the true rhinos (family Rhinocerotidae), three artiodactyl families (Entelodontidae, Anthracotheriidae and Gelocidae) related respectively to pigs, hippos and ruminants, the rodent families Eomyidae, Cricetidae (hamsters) and Castoridae (beavers), and the lipotyphlan family Erinaceidae (hedgehogs). Pigs, also called hogs or' swine', are Ungulates which have been domesticated as sources of food leather and similar products since ancient times The hippopotamus ( Hippopotamus amphibius) from the Greek ἱπποπόταμος ( hippopotamos, ιππος hippos meaning "horse" Physiologically a ruminant is a Mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first stomach known Rodentia is an order of Mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must Hamsters are Rodents belonging to the Subfamily Cricetinae. The subfamily contains about 18 Species, classified in six or seven genera Beavers are two primarily nocturnal semi-aquatic species of Rodent, one native to North America and one to Europe A hedgehog is any of the small spiny Mammals of the Subfamily Erinaceinae and the order Erinaceomorpha. The speciose genus Palaeotherium plus Anoplotherium and the families Xiphodontidae and Amphimerycidae were observed to disappear completely.

"Only the marsupial family Herpetotheriidae, the artiodactyl family Cainotheriidae, and the rodent families Theridomyidae and Gliridae (dormice) crossed the faunal divide undiminished. Marsupials are an Infraclass of Mammals characterized by a distinctive pouch (called the marsupium) in which females carry their young through Cainotherium commune was a small Rabbit -sized Herbivore that lived in Europe during the Oligocene. Dormice are Rodents of the family Gliridae. (This family is also variously called Myoxidae or Muscardinidae by different taxonomists " (Hooker et al. 2004)

Whether this abrupt change was caused by climate change associated with the earliest polar glaciations^[8] and a major fall in sea levels, or by competition with taxa dispersing from Asia, few argue for an isolated single cause. Climate change is any long-term significant change in the “average weather” that a given region experiences More spectacular causes are related to the impact of one or more large bolides in Siberia and in the Chesapeake Bay impact crater. Improved correlation of northwest European successions to global events (Hooker et al. North-West Europe is a term that refers to a northern area of Western Europe, although the exact area or countries it comprises varies 2004) confirms the Grande Coupure as occurring in the earliest Oligocene, with a hiatus of about 350 millennia prior to the first record of post-Grande Coupure Asian immigrant taxa. A millennium (pl millennia) is a period of Time equal to one thousand Years (from Latin la mille, thousand and la annum

An element of the paradigm of the Grande Coupure was the apparent extinction of all European primates at the Coupure: the recent discovery^[9] of a mouse-sized early Oligocene omomyid, reflecting the better survival chances of small mammals, further undercut the Grand Coupure paradigm. In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. A mouse (plural mice) is a small Animal that belongs to one Omomyids (members of the family Omomyidae) are a diverse group of extinct primates that radiated during the Eocene epoch between about 55 and 34 million The word paradigm ( Greek:παράδειγμα (paradigmacomposite from para- and the verb δείχνυμι "to show" as a whole -roughly- meaning "example"

See also

• Green River Formation in western North America
• List of fossil sites (with link directory)
• London Clay
• Messel Pit in Germany

Notes

References

• Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sections and Points (GSSP's) http://www.stratigraphy.org/gssp.htm Accessed April 30, 2006.
• Stanley, Steven M. Earth System History. New York: W. New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous H. Freeman and Company, 1999. ISBN 0-7167-2882-6
• J. J. Hooker M. E. Collinson and N. P. Sille, 2004. "Eocene–Oligocene mammalian faunal turnover in the Hampshire Basin, England: calibration to the global time scale and the major cooling event" in Journal of the Geological Society 161. The Hampshire Basin is a Geological Syncline in Southern England underlying parts of Hampshire, the Isle of Wight, Dorset England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland 2, pp 161-172 (on-line text)

External links

• PaleoMap Project
• Paleos Eocene page
• PBS Deep Time: Eocene
• Eocene Fossils
• Eocene and Oligocene Fossils
• Eocene Primate, Carnegie Museum of Natural History
• The UPenn Fossil Forest Project, focusing on the Eocene polar forests in Ellesmere Island, Canada
• Basilosaurus Primitive Eocene Whales
• Eocene Whale Origins
• Detailed maps of Tertiary Western North America
• Map of Eocene Earth

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