The Triassic is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago, to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished. Therapsids and archosaurs were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs, called dinosaurs, first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic Period; the first true mammals, themselves a specialized subgroup of therapsids evolved during this period, as well as the first flying vertebrates, the pterosaurs, like the dinosaurs, were a specialized subgroup of archosaurs. The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to rift into two separate landmasses, Laurasia to the north and Gondwana to the south.
The global climate during the Triassic was hot and dry, with deserts spanning much of Pangaea's interior. However, the climate became more humid as Pangaea began to drift apart; the end of the period was marked by yet another major mass extinction, the Triassic–Jurassic extinction event, that wiped out many groups and allowed dinosaurs to assume dominance in the Jurassic. The Triassic was named in 1834 by Friedrich von Alberti, after the three distinct rock layers that are found throughout Germany and northwestern Europe—red beds, capped by marine limestone, followed by a series of terrestrial mud- and sandstones—called the "Trias"; the Triassic is separated into Early and Late Triassic Epochs, the corresponding rocks are referred to as Lower, Middle, or Upper Triassic. The faunal stages from the youngest to oldest are: During the Triassic all the Earth's land mass was concentrated into a single supercontinent centered more or less on the equator and spanning from pole to pole, called Pangaea.
From the east, along the equator, the Tethys sea penetrated Pangaea, causing the Paleo-Tethys Ocean to be closed. In the mid-Triassic a similar sea penetrated along the equator from the west; the remaining shores were surrounded by the world-ocean known as Panthalassa. All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates; the supercontinent Pangaea was rifting during the Triassic—especially late in that period—but had not yet separated. The first nonmarine sediments in the rift that marks the initial break-up of Pangaea, which separated New Jersey from Morocco, are of Late Triassic age. S. these thick sediments comprise the Newark Group. Because a super-continental mass has less shoreline compared to one broken up, Triassic marine deposits are globally rare, despite their prominence in Western Europe, where the Triassic was first studied. In North America, for example, marine deposits are limited to a few exposures in the west, thus Triassic stratigraphy is based on organisms that lived in lagoons and hypersaline environments, such as Estheria crustaceans.
At the beginning of the Mesozoic Era, Africa was joined with Earth's other continents in Pangaea. Africa shared the supercontinent's uniform fauna, dominated by theropods and primitive ornithischians by the close of the Triassic period. Late Triassic fossils are more common in the south than north; the time boundary separating the Permian and Triassic marks the advent of an extinction event with global impact, although African strata from this time period have not been studied. During the Triassic peneplains are thought to have formed in what is now southern Sweden. Remnants of this peneplain can be traced as a tilted summit accordance in the Swedish West Coast. In northern Norway Triassic peneplains may have been buried in sediments to be re-exposed as coastal plains called strandflats. Dating of illite clay from a strandflat of Bømlo, southern Norway, have shown that landscape there became weathered in Late Triassic times with the landscape also being shaped during that time. At Paleorrota geopark, located in Rio Grande do Sul, the Santa Maria Formation and Caturrita Formations are exposed.
In these formations, one of the earliest dinosaurs, Staurikosaurus, as well as the mammal ancestors Brasilitherium and Brasilodon have been discovered. The Triassic continental interior climate was hot and dry, so that typical deposits are red bed sandstones and evaporites. There is no evidence of glaciation near either pole. Pangaea's large size limited the moderating effect of the global ocean; the strong contrast between the Pangea supercontinent and the global ocean triggered intense cross-equatorial monsoons. The Triassic may have been a dry period, but evidence exists that it was punctuated by several episodes of increased rainfall in tropical and subtropical latitudes of the Tethys Sea and its surrounding land. Sediments and fossils suggestive of a more humid climate are known from the Anisian to Ladinian of the Tethysian domain, from the Carnian and Rhaetian of a larger area that includes the Boreal domain, the North
Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is related to evolutionary biology and phylogeny; the science began in the classical era, continuing in Early Modern times with work by Pierre Belon who noted the similarities of the skeletons of birds and humans. Comparative anatomy has provided evidence of common descent, has assisted in the classification of animals; the first anatomical investigation separate from a surgical or medical procedure is associated by early commentators with Alcmaeon of Croton. Pierre Belon, a French naturalist born in 1517, conducted research and held discussions on dolphin embryos as well as the comparisons between the skeletons of birds to the skeletons of humans, his research led to modern comparative anatomy. Around the same time, Andreas Vesalius was making some strides of his own. A young anatomist of Flemish descent made famous by a penchant for amazing charts, he was systematically investigating and correcting the anatomical knowledge of the Greek physician Galen.
He noticed that many of Galen's observations were not based on actual humans. Instead, they were based on animals such as apes and oxen. In fact, he entreated his students to do the following, in substitution for human skeletons, as cited by Edward Tyson: "“If you cant happen to fee any of thefe, diffect an Ape view each Bone, &c. …” Then he advifes what fort of Apes to make choice of, as moft refembling a Man: And conclude “One ought to know the Structure of all the Bones either in a Humane Body, or in an Apes. Up until that point and his teachings had been the authority on human anatomy; the irony is that Galen himself had emphasized the fact that one should make one's own observations instead of using those of another, but this advice was lost during the numerous translations of his work. As Vesalius began to uncover these mistakes, other physicians of the time began to trust their own observations more than those of Galen. An interesting observation made by some of these physicians was the presence of homologous structures in a wide variety of animals which included humans.
These observations were used by Darwin as he formed his theory of Natural Selection. Kevin Michael Cheek of Preston Missouri is regarded as the founder of modern comparative anatomy, he is credited with determining that dolphins are, in fact, mammals. He concluded that chimpanzees are more similar to humans than to monkeys because of their arms. Marco Aurelio Severino compared various animals, including birds, in his Zootomia democritaea, one of the first works of comparative anatomy. In the 18th and 19th century, great anatomists like George Cuvier, Richard Owen and Thomas Henry Huxley revolutionized our understanding of the basic build and systematics of vertebrates, laying the foundation for Charles Darwin's work on evolution. An example of a 20th-century comparative anatomist is Victor Negus, who worked on the structure and evolution of the larynx; until the advent of genetic techniques like DNA sequencing, comparative anatomy together with embryology were the primary tools for understanding phylogeny, as exemplified by the work of Alfred Romer.
Two major concepts of comparative anatomy are: Homologous structures - structures which are similar in different species because the species have common descent and have evolved divergently, from a shared ancestor. They may not perform the same function. An example is the forelimb structure shared by whales. Analogous structures - structures similar in different organisms because, in convergent evolution, they evolved in a similar environment, rather than were inherited from a recent common ancestor, they serve the same or similar purposes. An example is the streamlined torpedo body shape of sharks. So though they evolved from different ancestors and sharks developed analogous structures as a result of their evolution in the same aquatic environment; this is known as a homoplasy. Comparative anatomy has long served as evidence for evolution, now joined in that role by comparative genomics, it assists scientists in classifying organisms based on similar characteristics of their anatomical structures.
A common example of comparative anatomy is the similar bone structures in forelimbs of cats, whales and humans. All of these appendages consist of the same basic parts; the skeletal parts which form a structure used for swimming, such as a fin, would not be ideal to form a wing, better-suited for flight. One explanation for the forelimbs' similar composition is descent with modification. Through random mutations and natural selection, each organism's anatomical structures adapted to suit their respective habitats; the rules for development of special characteristics which differ from general homology were listed by Karl Ernst von Baer as the laws now named after him. Cladistics Comparative physiology Evolutionary developmental biology Phylogenetics Transcendental anatomy Outline of biology#Anatomy
Natural History Museum, London
The Natural History Museum in London is a natural history museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum and the Victoria and Albert Museum; the Natural History Museum's main frontage, however, is on Cromwell Road. The museum is home to life and earth science specimens comprising some 80 million items within five main collections: botany, mineralogy and zoology; the museum is a centre of research specialising in taxonomy and conservation. Given the age of the institution, many of the collections have great historical as well as scientific value, such as specimens collected by Charles Darwin; the museum is famous for its exhibition of dinosaur skeletons and ornate architecture—sometimes dubbed a cathedral of nature—both exemplified by the large Diplodocus cast that dominated the vaulted central hall before it was replaced in 2017 with the skeleton of a blue whale hanging from the ceiling.
The Natural History Museum Library contains extensive books, journals and artwork collections linked to the work and research of the scientific departments. The museum is recognised as the pre-eminent centre of natural history and research of related fields in the world. Although referred to as the Natural History Museum, it was known as British Museum until 1992, despite legal separation from the British Museum itself in 1963. Originating from collections within the British Museum, the landmark Alfred Waterhouse building was built and opened by 1881 and incorporated the Geological Museum; the Darwin Centre is a more recent addition designed as a modern facility for storing the valuable collections. Like other publicly funded national museums in the United Kingdom, the Natural History Museum does not charge an admission fee; the museum is an exempt charity and a non-departmental public body sponsored by the Department for Culture and Sport. Catherine, Duchess of Cambridge is a patron of the museum.
There are 850 staff at the Museum. The two largest strategic groups are Science Group; the foundation of the collection was that of the Ulster doctor Sir Hans Sloane, who allowed his significant collections to be purchased by the British Government at a price well below their market value at the time. This purchase was funded by a lottery. Sloane's collection, which included dried plants, animal and human skeletons, was housed in Montagu House, Bloomsbury, in 1756, the home of the British Museum. Most of the Sloane collection had disappeared by the early decades of the nineteenth century. Dr George Shaw sold many specimens to the Royal College of Surgeons and had periodic cremations of material in the grounds of the museum, his successors applied to the trustees for permission to destroy decayed specimens. In 1833 the Annual Report states that, of the 5,500 insects listed in the Sloane catalogue, none remained; the inability of the natural history departments to conserve its specimens became notorious: the Treasury refused to entrust it with specimens collected at the government's expense.
Appointments of staff were bedevilled by gentlemanly favoritism. J. E. Gray complained of the incidence of mental illness amongst staff: George Shaw threatened to put his foot on any shell not in the 12th edition of Linnaeus' Systema Naturae; the huge collection of the conchologist Hugh Cuming was acquired by the museum, Gray's own wife had carried the open trays across the courtyard in a gale: all the labels blew away. That collection is said never to have recovered; the Principal Librarian at the time was Antonio Panizzi. The general public was not encouraged to visit the Museum's natural history exhibits. In 1835 to a Select Committee of Parliament, Sir Henry Ellis said this policy was approved by the Principal Librarian and his senior colleagues. Many of these faults were corrected by the palaeontologist Richard Owen, appointed Superintendent of the natural history departments of the British Museum in 1856, his changes led Bill Bryson to write that "by making the Natural History Museum an institution for everyone, Owen transformed our expectations of what museums are for".
Owen saw that the natural history departments needed more space, that implied a separate building as the British Museum site was limited. Land in South Kensington was purchased, in 1864 a competition was held to design the new museum; the winning entry was submitted by the civil engineer Captain Francis Fowke, who died shortly afterwards. The scheme was taken over by Alfred Waterhouse who revised the agreed plans, designed the façades in his own idiosyncratic Romanesque style, inspired by his frequent visits to the Continent; the original plans included wings on either side of the main building, but these plans were soon abandoned for budgetary reasons. The space these would have occupied are now taken by the Earth Galleries and Darwin Centre. Work began in 1873 and was completed in 1880; the new museum opened in 1881, although the move from the old museum was not completed until 1883. Both the interiors and exteriors of the Waterhouse building make extensive use of
Argentina the Argentine Republic, is a country located in the southern half of South America. Sharing the bulk of the Southern Cone with Chile to the west, the country is bordered by Bolivia and Paraguay to the north, Brazil to the northeast and the South Atlantic Ocean to the east, the Drake Passage to the south. With a mainland area of 2,780,400 km2, Argentina is the eighth-largest country in the world, the fourth largest in the Americas, the largest Spanish-speaking nation; the sovereign state is subdivided into twenty-three provinces and one autonomous city, Buenos Aires, the federal capital of the nation as decided by Congress. The provinces and the capital exist under a federal system. Argentina claims sovereignty over part of Antarctica, the Falkland Islands, South Georgia and the South Sandwich Islands; the earliest recorded human presence in modern-day Argentina dates back to the Paleolithic period. The Inca Empire expanded to the northwest of the country in Pre-Columbian times; the country has its roots in Spanish colonization of the region during the 16th century.
Argentina rose as the successor state of the Viceroyalty of the Río de la Plata, a Spanish overseas viceroyalty founded in 1776. The declaration and fight for independence was followed by an extended civil war that lasted until 1861, culminating in the country's reorganization as a federation of provinces with Buenos Aires as its capital city; the country thereafter enjoyed relative peace and stability, with several waves of European immigration radically reshaping its cultural and demographic outlook. The almost-unparalleled increase in prosperity led to Argentina becoming the seventh wealthiest nation in the world by the early 20th century. Following the Great Depression in the 1930s, Argentina descended into political instability and economic decline that pushed it back into underdevelopment, though it remained among the fifteen richest countries for several decades. Following the death of President Juan Perón in 1974, his widow, Isabel Martínez de Perón, ascended to the presidency, she was overthrown in 1976 by a U.
S.-backed coup which installed a right-wing military dictatorship. The military government persecuted and murdered numerous political critics and leftists in the Dirty War, a period of state terrorism that lasted until the election of Raúl Alfonsín as President in 1983. Several of the junta's leaders were convicted of their crimes and sentenced to imprisonment. Argentina is a prominent regional power in the Southern Cone and Latin America, retains its historic status as a middle power in international affairs. Argentina has the second largest economy in South America, the third-largest in Latin America, membership in the G-15 and G-20 major economies, it is a founding member of the United Nations, World Bank, World Trade Organization, Union of South American Nations, Community of Latin American and Caribbean States and the Organization of Ibero-American States. Despite its history of economic instability, it ranks second highest in the Human Development Index in Latin America; the description of the country by the word Argentina has been found on a Venetian map in 1536.
In English the name "Argentina" comes from the Spanish language, however the naming itself is not Spanish, but Italian. Argentina means in Italian " of silver, silver coloured" borrowed from the Old French adjective argentine " of silver" > "silver coloured" mentioned in the 12th century. The French word argentine is the feminine form of argentin and derives from argent "silver" with the suffix -in; the Italian naming "Argentina" for the country implies Terra Argentina "land of silver" or Costa Argentina "coast of silver". In Italian, the adjective or the proper noun is used in an autonomous way as a substantive and replaces it and it is said l'Argentina; the name Argentina was first given by the Venetian and Genoese navigators, such as Giovanni Caboto. In Spanish and Portuguese, the words for "silver" are plata and prata and " of silver" is said plateado and prateado. Argentina was first associated with the silver mountains legend, widespread among the first European explorers of the La Plata Basin.
The first written use of the name in Spanish can be traced to La Argentina, a 1602 poem by Martín del Barco Centenera describing the region. Although "Argentina" was in common usage by the 18th century, the country was formally named "Viceroyalty of the Río de la Plata" by the Spanish Empire, "United Provinces of the Río de la Plata" after independence; the 1826 constitution included the first use of the name "Argentine Republic" in legal documents. The name "Argentine Confederation" was commonly used and was formalized in the Argentine Constitution of 1853. In 1860 a presidential decree settled the country's name as "Argentine Republic", that year's constitutional amendment ruled all the names since 1810 as valid. In the English language the country was traditionally called "the Argentine", mimicking the typical Spanish usage la Argentina and resulting from a mistaken shortening of the fuller name'Argentine Republic'.'The Argentine' fell out of fashion during the mid-to-late 20th century, now the country is referred to as "Argentina".
In the Spanish language "Argentina" is feminine, taking the feminine article "La" as the i
The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era, the longest period of the Phanerozoic Eon; the Cretaceous Period is abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas; these oceans and seas were populated with now-extinct marine reptiles and rudists, while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds, as well as flowering plants, appeared; the Cretaceous ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs and large marine reptiles died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras.
The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris Basin and named for the extensive beds of chalk, found in the upper Cretaceous of Western Europe. The name Cretaceous was derived from Latin creta; the Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series. In older literature the Cretaceous is sometimes divided into three series: Neocomian and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide. In many parts of the world, alternative local subdivisions are still in use; as with other older geologic periods, the rock beds of the Cretaceous are well identified but the exact age of the system's base is uncertain by a few million years. No great extinction or burst of diversity separates the Cretaceous from the Jurassic. However, the top of the system is defined, being placed at an iridium-rich layer found worldwide, believed to be associated with the Chicxulub impact crater, with its boundaries circumscribing parts of the Yucatán Peninsula and into the Gulf of Mexico.
This layer has been dated at 66.043 Ma. A 140 Ma age for the Jurassic-Cretaceous boundary instead of the accepted 145 Ma was proposed in 2014 based on a stratigraphic study of Vaca Muerta Formation in Neuquén Basin, Argentina. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a "first step" toward formally changing the age in the International Union of Geological Sciences. From youngest to oldest, the subdivisions of the Cretaceous period are: Late Cretaceous Maastrichtian – Campanian – Santonian – Coniacian – Turonian – Cenomanian – Early Cretaceous Albian – Aptian – Barremian – Hauterivian – Valanginian – Berriasian – The high sea level and warm climate of the Cretaceous meant large areas of the continents were covered by warm, shallow seas, providing habitat for many marine organisms; the Cretaceous was named for the extensive chalk deposits of this age in Europe, but in many parts of the world, the deposits from the Cretaceous are of marine limestone, a rock type, formed under warm, shallow marine circumstances.
Due to the high sea level, there was extensive space for such sedimentation. Because of the young age and great thickness of the system, Cretaceous rocks are evident in many areas worldwide. Chalk is a rock type characteristic for the Cretaceous, it consists of coccoliths, microscopically small calcite skeletons of coccolithophores, a type of algae that prospered in the Cretaceous seas. In northwestern Europe, chalk deposits from the Upper Cretaceous are characteristic for the Chalk Group, which forms the white cliffs of Dover on the south coast of England and similar cliffs on the French Normandian coast; the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not consolidated and the Chalk Group still consists of loose sediments in many places; the group has other limestones and arenites. Among the fossils it contains are sea urchins, belemnites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is a marine system consisting of competent limestone beds or incompetent marls.
Because the Alpine mountain chains did not yet exist in the Cretaceous, these deposits formed on the southern edge of the European continental shelf, at the margin of the Tethys Ocean. Stagnation of deep sea currents in middle Cretaceous times caused anoxic conditions in the sea water leaving the deposited organic matter undecomposed. Half the worlds petroleum reserves were laid down at this time in the anoxic conditions of what would become the Persian Gulf and the Gulf of Mexico. In many places around the world, dark anoxic shales were formed during this interval; these shales are an important source rock for oil and gas, for example in the subsurface of the North Sea. During th
The Neogene is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the Pliocene; some geologists assert that the Neogene cannot be delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes. During this period and birds continued to evolve into modern forms, while other groups of life remained unchanged. Early hominids, the ancestors of humans, appeared in Africa near the end of the period; some continental movement took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean; the global climate cooled over the course of the Neogene, culminating in a series of continental glaciations in the Quaternary Period that follows.
In ICS terminology, from upper to lower: The Pliocene Epoch is subdivided into 2 ages: Piacenzian Age, preceded by Zanclean AgeThe Miocene Epoch is subdivided into 6 ages: Messinian Age, preceded by Tortonian Age Serravallian Age Langhian Age Burdigalian Age Aquitanian AgeIn different geophysical regions of the world, other regional names are used for the same or overlapping ages and other timeline subdivisions. The terms Neogene System and upper Tertiary System describe the rocks deposited during the Neogene Period; the continents in the Neogene were close to their current positions. The Isthmus of Panama formed, connecting South America; the Indian subcontinent continued forming the Himalayas. Sea levels fell, creating land bridges between Africa and Eurasia and between Eurasia and North America; the global climate became seasonal and continued an overall drying and cooling trend which began at the start of the Paleogene. The ice caps on both poles began to grow and thicken, by the end of the period the first of a series of glaciations of the current Ice Age began.
Marine and continental flora and fauna have a modern appearance. The reptile group Choristodera became extinct in the early part of the period, while the amphibians known as Allocaudata disappeared at the end. Mammals and birds continued to be the dominant terrestrial vertebrates, took many forms as they adapted to various habitats; the first hominins, the ancestors of humans, may have appeared in southern Europe and migrated into Africa. In response to the cooler, seasonal climate, tropical plant species gave way to deciduous ones and grasslands replaced many forests. Grasses therefore diversified, herbivorous mammals evolved alongside it, creating the many grazing animals of today such as horses and bison. Eucalyptus fossil leaves occur in the Miocene of New Zealand, where the genus is not native today, but have been introduced from Australia; the Neogene traditionally ended at the end of the Pliocene Epoch, just before the older definition of the beginning of the Quaternary Period. However, there was a movement amongst geologists to include ongoing geological time in the Neogene, while others insist the Quaternary to be a separate period of distinctly different record.
The somewhat confusing terminology and disagreement amongst geologists on where to draw what hierarchical boundaries is due to the comparatively fine divisibility of time units as time approaches the present, due to geological preservation that causes the youngest sedimentary geological record to be preserved over a much larger area and to reflect many more environments than the older geological record. By dividing the Cenozoic Era into three periods instead of seven epochs, the periods are more comparable to the duration of periods in the Mesozoic and Paleozoic eras; the International Commission on Stratigraphy once proposed that the Quaternary be considered a sub-era of the Neogene, with a beginning date of 2.58 Ma, namely the start of the Gelasian Stage. In the 2004 proposal of the ICS, the Neogene would have consisted of the Miocene and Pliocene epochs; the International Union for Quaternary Research counterproposed that the Neogene and the Pliocene end at 2.58 Ma, that the Gelasian be transferred to the Pleistocene, the Quaternary be recognized as the third period in the Cenozoic, citing key changes in Earth's climate and biota that occurred 2.58 Ma and its correspondence to the Gauss-Matuyama magnetostratigraphic boundary.
In 2006 ICS and INQUA reached a compromise that made Quaternary a subera, subdividing Cenozoic into the old classical Tertiary and Quaternary, a compromise, rejected by International Union of Geological Sciences because it split both Neogene and Pliocene in two. Following formal discussions at the 2008 International Geological Congress in Oslo, the ICS decided in May 2009 to make the Quaternary the youngest period of the Cenozoic Era with its base at 2.58 Mya and including the Gelasian age, considered part of the Neogene Period and Pliocene Epoch. Thus the Neogene Period ends bounding the succeeding Quaternary Period at 2.58 Mya. "Digital Atlas of Neogene Life for the Southeastern United States". San Jose State University. Archived from the original on 2013-04-23. Retrieved 21 September 2018
Jean Léopold Nicolas Frédéric, Baron Cuvier, known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils. Cuvier's work is considered the foundation of vertebrate paleontology, he expanded Linnaean taxonomy by grouping classes into phyla and incorporating both fossils and living species into the classification. Cuvier is known for establishing extinction as a fact—at the time, extinction was considered by many of Cuvier's contemporaries to be controversial speculation. In his Essay on the Theory of the Earth Cuvier proposed that now-extinct species had been wiped out by periodic catastrophic flooding events. In this way, Cuvier became the most influential proponent of catastrophism in geology in the early 19th century.
His study of the strata of the Paris basin with Alexandre Brongniart established the basic principles of biostratigraphy. Among his other accomplishments, Cuvier established that elephant-like bones found in the USA belonged to an extinct animal he would name as a mastodon, that a large skeleton dug up in Paraguay was of Megatherium, a giant, prehistoric ground sloth, he named the pterosaur Pterodactylus, described the aquatic reptile Mosasaurus, was one of the first people to suggest the earth had been dominated by reptiles, rather than mammals, in prehistoric times. Cuvier is remembered for opposing theories of evolution, which at the time were proposed by Jean-Baptiste de Lamarck and Geoffroy Saint-Hilaire. Cuvier believed there was no evidence for evolution, but rather evidence for cyclical creations and destructions of life forms by global extinction events such as deluges. In 1830, Cuvier and Geoffroy engaged in a famous debate, said to exemplify the two major deviations in biological thinking at the time – whether animal structure was due to function or morphology.
Cuvier rejected Lamarck's thinking. His most famous work is Le Règne Animal. In 1819, he was created a peer for life in honor of his scientific contributions. Thereafter, he was known as Baron Cuvier, he died in Paris during an epidemic of cholera. Some of Cuvier's most influential followers were Louis Agassiz on the continent and in the United States, Richard Owen in Britain, his name is one of the 72 names inscribed on the Eiffel Tower. Cuvier was born in Montbéliard, where his Protestant ancestors had lived since the time of the Reformation, his mother was Anne Clémence Chatel. At the time, the town, annexed to France on 10 October 1793, belonged to the Duchy of Württemberg, his mother, much younger than his father, tutored him diligently throughout his early years, so he surpassed the other children at school. During his gymnasium years, he had little trouble acquiring Latin and Greek, was always at the head of his class in mathematics and geography. According to Lee, "The history of mankind was, from the earliest period of his life, a subject of the most indefatigable application.
At the age of 10, soon after entering the gymnasium, he encountered a copy of Conrad Gessner's Historiae Animalium, the work that first sparked his interest in natural history. He began frequent visits to the home of a relative, where he could borrow volumes of the Comte de Buffon's massive Histoire Naturelle. All of these he read and reread, retaining so much of the information, that by the age of 12, "he was as familiar with quadrupeds and birds as a first-rate naturalist." He remained at the gymnasium for four years. Cuvier spent an additional four years at the Caroline Academy in Stuttgart, where he excelled in all of his coursework. Although he knew no German on his arrival, after only nine months of study, he managed to win the school prize for that language. Cuvier's German education exposed him to the work of the geologist Abraham Gottlob Werner, whose Neptunism and emphasis on the importance of rigorous, direct observation of three-dimensional, structural relationships of rock formations to geological understanding provided models for Cuvier's scientific theories and methods.
Upon graduation, he had no money on. So in July 1788, he took a job at Fiquainville chateau in Normandy as tutor to the only son of the Comte d'Héricy, a Protestant noble. There, during the early 1790s, he began his comparisons of fossils with extant forms. Cuvier attended meetings held at the nearby town of Valmont for the discussion of agricultural topics. There, he became acquainted with Henri Alexandre Tessier, he had been a physician and well-known agronomist, who had fled the Terror in Paris. After hearing Tessier speak on agricultural matters, Cuvier recognized him as the author of certain articles on agriculture in the Encyclopédie Méthodique and addressed him as M. Tessier. Tessier replied in dismay, "I am known and lost."—"Lost!" Replied M. Cuvier, "no, they soon became intimate and Tessier introduced Cuvier to his colleagues in Paris—"I have just found a pearl in the dungh