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A paleontologist at work atJohn Day Fossil beds National Monument

Paleontology(/ˌpeɪliɒnˈtɒlədʒi,ˌpæli-,-ən-/PAY-lee-on-TOL-ə-jee,PAL-ee-, -⁠ən-), also spelledpalaeontology[a]orpalæontology,is the scientific study of life that existed prior to the start of theHoloceneepoch(roughly 11,700 years before present).[citation needed]It includes the study offossilsto classifyorganismsand study theirinteractionswith each other and their environments (theirpaleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result ofGeorges Cuvier's work oncomparative anatomy,and developed rapidly in the 19th century. The term has been used since 1822[1][b]formed fromGreekπαλαιός('palaios',"old, ancient" ),ὄν('on',(gen.'ontos'), "being, creature" ), andλόγος('logos',"speech, thought, study" ).[3]

Paleontology lies on the border betweenbiologyandgeology,but it differs fromarchaeologyin that it excludes the study ofanatomically modern humans.It now uses techniques drawn from a wide range of sciences, includingbiochemistry,mathematics,and engineering. Use of all these techniques has enabled paleontologists to discover much of theevolutionary history of life,almost back to when Earth became capable of supporting life, nearly 4 billion years ago.[4]As knowledge has increased, paleontology has developed specialised sub-divisions, some of which focus on different types of fossil organisms while others studyecologyand environmental history, such asancient climates.

Body fossils andtrace fossilsare the principal types of evidence about ancient life, andgeochemicalevidence has helped to decipher the evolution of life before there were organisms large enough to leave body fossils. Estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allowradiometric dating,which providesabsolute datesthat are accurate to within 0.5%, but more often paleontologists have to rely on relative dating by solving the "jigsaw puzzles"ofbiostratigraphy(arrangement of rock layers from youngest to oldest). Classifying ancient organisms is also difficult, as many do not fit well into theLinnaean taxonomyclassifying living organisms, and paleontologists more often usecladisticsto draw up evolutionary "family trees". The final quarter of the 20th century saw the development ofmolecular phylogenetics,which investigates how closely organisms are related by measuring the similarity of theDNAin theirgenomes.Molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of themolecular clockon which such estimates depend.

Overview

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The simplest definition of "paleontology" is "the study of ancient life".[5]The field seeks information about several aspects of past organisms: "their identity and origin, their environment and evolution, and what they can tell us about the Earth's organic and inorganic past".[6]

Historical science

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The preparation of the fossilised bones ofEuropasaurusholgeri

William Whewell(1794–1866) classified paleontology as one of the historical sciences, along witharchaeology,geology,astronomy,cosmology,philologyand history itself:[7]paleontology aims to describe phenomena of the past and to reconstruct their causes.[8]Hence it has three main elements: description of past phenomena; developing a general theory about the causes of various types of change; and applying those theories to specific facts.[9] When trying to explain the past, paleontologists and other historical scientists often construct a set of one or morehypothesesabout the causes and then look for a "smoking gun",a piece of evidence that strongly accords with one hypothesis over any others.[10] Sometimes researchers discover a "smoking gun" by a fortunate accident during other research. For example, the 1980 discovery byLuisandWalter Alvarezofiridium,a mainly extraterrestrial metal, in theCretaceous–Paleogeneboundary layer madeasteroid impactthe most favored explanation for theCretaceous–Paleogene extinction event– although debate continues about the contribution of volcanism.[8]

A complementary approach to developing scientific knowledge,experimental science,[11] is often said[by whom?]to work by conducting experiments todisprovehypotheses about the workings and causes of natural phenomena. This approach cannot prove a hypothesis, since some later experiment may disprove it, but the accumulation of failures to disprove is often compelling evidence in favor. However, when confronted with totally unexpected phenomena, such as the first evidence for invisibleradiation,experimental scientists often use the same approach as historical scientists: construct a set of hypotheses about the causes and then look for a "smoking gun".[8]

[edit]

Paleontology lies betweenbiologyand geology since it focuses on the record of past life, but its main source of evidence isfossilsin rocks.[12][13]For historical reasons, paleontology is part of the geology department at many universities: in the 19th and early 20th centuries, geology departments found fossil evidence important for dating rocks, while biology departments showed little interest.[14]

Paleontology also has some overlap witharchaeology,which primarily works with objects made by humans and with human remains, while paleontologists are interested in the characteristics and evolution of humans as a species. When dealing with evidence about humans, archaeologists and paleontologists may work together – for example paleontologists might identify animal or plant fossils around anarchaeological site,to discover the people who lived there, and what they ate; or they might analyze the climate at the time of habitation.[15]

In addition, paleontology often borrows techniques from other sciences, including biology,osteology,ecology,chemistry,physicsand mathematics.[5]For example,geochemicalsignatures from rocks may help to discover when life first arose on Earth,[16]and analyses ofcarbonisotope ratiosmay help to identify climate changes and even to explain major transitions such as thePermian–Triassic extinction event.[17]A relatively recent discipline,molecular phylogenetics,compares theDNAandRNAof modern organisms to re-construct the "family trees" of their evolutionary ancestors. It has also been used to estimate the dates of important evolutionary developments, although this approach is controversial because of doubts about the reliability of the "molecular clock".[18]Techniques from engineering have been used to analyse how the bodies of ancient organisms might have worked, for example the running speed and bite strength ofTyrannosaurus,[19][20]or the flight mechanics ofMicroraptor.[21]It is relatively commonplace to study the internal details of fossils usingX-ray microtomography.[22][23]Paleontology, biology, archaeology, andpaleoneurobiologycombine to study endocranial casts (endocasts) of species related to humans to clarify the evolution of the human brain.[24]

Paleontology even contributes toastrobiology,the investigation of possible life on otherplanets,by developing models of how life may have arisen and by providing techniques for detecting evidence of life.[25]

Subdivisions

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As knowledge has increased, paleontology has developed specialised subdivisions.[26]Vertebrate paleontologyconcentrates on fossils from the earliest fish to the immediate ancestors of modernmammals.Invertebrate paleontologydeals with fossils such asmolluscs,arthropods,annelidworms andechinoderms.Paleobotanystudies fossilplants,algae,and fungi.Palynology,the study ofpollenandsporesproduced by land plants andprotists,straddles paleontology andbotany,as it deals with both living and fossil organisms.Micropaleontologydeals with microscopic fossil organisms of all kinds.[27]

Analyses using engineering techniques show thatTyrannosaurushad a devastating bite, but raise doubts about its running ability.

Instead of focusing on individual organisms,paleoecologyexamines the interactions between different ancient organisms, such as theirfood chains,and the two-way interactions with their environments.[28]For example, the development ofoxygenic photosynthesisby bacteria caused theoxygenation of the atmosphereand hugely increased the productivity and diversity ofecosystems.[29]Together, these led to the evolution of complexeukaryoticcells, from which allmulticellularorganisms are built.[30]

Paleoclimatology,although sometimes treated as part of paleoecology,[27]focuses more on the history of Earth's climate and the mechanisms that have changed it[31]– which have sometimes includedevolutionarydevelopments, for example the rapid expansion of land plants in theDevonianperiod removed morecarbon dioxidefrom the atmosphere, reducing thegreenhouse effectand thus helping to cause anice agein theCarboniferousperiod.[32]

Biostratigraphy,the use of fossils to work out the chronological order in which rocks were formed, is useful to both paleontologists and geologists.[33]Biogeographystudies the spatial distribution of organisms, and is also linked to geology, which explains how Earth's geography has changed over time.[34]

Sources of evidence

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Body fossils

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Main article:Fossil
ThisMarrellaspecimen illustrates how clear and detailed the fossils from theBurgess Shalelagerstätteare.

Fossils of organisms' bodies are usually the most informative type of evidence. The most common types are wood, bones, and shells.[35]Fossilisation is a rare event, and most fossils are destroyed byerosionormetamorphismbefore they can be observed. Hence the fossil record is very incomplete, increasingly so further back in time. Despite this, it is often adequate to illustrate the broader patterns of life's history.[36]There are also biases in the fossil record: different environments are more favorable to the preservation of different types of organism or parts of organisms.[37]Further, only the parts of organisms that were alreadymineralisedare usually preserved, such as the shells of molluscs. Since most animal species are soft-bodied, they decay before they can become fossilised. As a result, although there are 30-plusphylaof living animals, two-thirds have never been found as fossils.[5]

Occasionally, unusual environments may preserve soft tissues.[38]Theselagerstättenallow paleontologists to examine the internal anatomy of animals that in other sediments are represented only by shells, spines, claws, etc. – if they are preserved at all. However, even lagerstätten present an incomplete picture of life at the time. The majority of organisms living at the time are probably not represented because lagerstätten are restricted to a narrow range of environments, e.g. where soft-bodied organisms can be preserved very quickly by events such as mudslides; and the exceptional events that cause quick burial make it difficult to study the normal environments of the animals.[39]The sparseness of the fossil record means that organisms are expected to exist long before and after they are found in the fossil record – this is known as theSignor–Lipps effect.[40]

Trace fossils

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Cambriantrace fossilsincludingRusophycus,made by atrilobite
Climactichnites— Cambrian trackways (10–12 cm wide) from large, slug-like animals on a Cambriantidal flatin what is nowWisconsin
Main article:Trace fossil

Trace fossilsconsist mainly of tracks and burrows, but also includecoprolites(fossilfeces) and marks left by feeding.[35][41]Trace fossils are particularly significant because they represent a data source that is not limited to animals with easily fossilised hard parts, and they reflect organisms' behaviours. Also many traces date from significantly earlier than the body fossils of animals that are thought to have been capable of making them.[42]Whilst exact assignment of trace fossils to their makers is generally impossible, traces may for example provide the earliest physical evidence of the appearance of moderately complex animals (comparable toearthworms).[41]

Geochemical observations

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Main article:Geochemistry

Geochemical observations may help to deduce the global level of biological activity at a certain period, or the affinity of certain fossils. For example, geochemical features of rocks may reveal when life first arose on Earth,[16]and may provide evidence of the presence ofeukaryoticcells, the type from which allmulticellularorganisms are built.[43]Analyses ofcarbonisotope ratiosmay help to explain major transitions such as thePermian–Triassic extinction event.[17]

Classifying ancient organisms

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Main articles:Biological classification,Cladistics,Phylogenetic nomenclature,andEvolutionary taxonomy
Levels in theLinnaean taxonomy

Naming groups of organisms in a way that is clear and widely agreed is important, as some disputes in paleontology have been based just on misunderstandings over names.[44]Linnaean taxonomyis commonly used for classifying living organisms, but runs into difficulties when dealing with newly discovered organisms that are significantly different from known ones. For example: it is hard to decide at what level to place a new higher-level grouping, e.g.genusorfamilyororder;this is important since the Linnaean rules for naming groups are tied to their levels, and hence if a group is moved to a different level it must be renamed.[45]

Tetrapods

Amphibians

Amniotes
Synapsids

Extinct Synapsids

Mammals

Reptiles

Extinct reptiles

Lizards and snakes

Archosaurs

Extinct
Archosaurs

Crocodilians

Dinosaurs
?

Extinct
Dinosaurs


?

Birds

Simple example cladogram
Warm-bloodedness evolved somewhere in the
synapsid–mammal transition.
?Warm-bloodedness must also have evolved at one of
these points – an example ofconvergent evolution.[5]

Paleontologists generally use approaches based oncladistics,a technique for working out the evolutionary "family tree" of a set of organisms.[44]It works by the logic that, if groups B and C have more similarities to each other than either has to group A, then B and C are more closely related to each other than either is to A. Characters that are compared may beanatomical,such as the presence of anotochord,ormolecular,by comparing sequences ofDNAorproteins.The result of a successful analysis is a hierarchy of clades – groups that share a common ancestor. Ideally the "family tree" has only two branches leading from each node ( "junction" ), but sometimes there is too little information to achieve this, and paleontologists have to make do with junctions that have several branches. The cladistic technique is sometimes fallible, as some features, such as wings orcamera eyes,evolved more than once,convergently– this must be taken into account in analyses.[5]

Evolutionary developmental biology,commonly abbreviated to "Evo Devo", also helps paleontologists to produce "family trees", and understand fossils.[46]For example, theembryologicaldevelopment of some modernbrachiopodssuggests that brachiopods may be descendants of thehalkieriids,which became extinct in theCambrianperiod.[47]

Estimating the dates of organisms

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Main article:Geochronology
Commonindex fossilsused to date rocks in the northeast United States

Paleontology seeks to map out how living things have changed through time. A substantial hurdle to this aim is the difficulty of working out how old fossils are. Beds that preserve fossils typically lack the radioactive elements needed forradiometric dating.This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better.[48]Although radiometric dating requires very careful laboratory work, its basic principle is simple: the rates at which various radioactive elementsdecayare known, and so the ratio of the radioactive element to the element into which it decays shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are a few volcanic ash layers.[48]

Consequently, paleontologists must usually rely onstratigraphyto date fossils. Stratigraphy is the science of deciphering the "layer-cake" that is thesedimentaryrecord, and has been compared to ajigsaw puzzle.[49]Rocks normally form relatively horizontal layers, with each layer younger than the one underneath it. If a fossil is found between two layers whose ages are known, the fossil's age must lie between the two known ages.[50]Because rock sequences are not continuous, but may be broken up byfaultsor periods oferosion,it is very difficult to match up rock beds that are not directly next to one another. However, fossils of species that survived for a relatively short time can be used to link up isolated rocks: this technique is calledbiostratigraphy.For instance, the conodontEoplacognathus pseudoplanushas a short range in the Middle Ordovician period.[51]If rocks of unknown age are found to have traces ofE. pseudoplanus,they must have a mid-Ordovician age. Suchindex fossilsmust be distinctive, be globally distributed and have a short time range to be useful. However, misleading results are produced if the index fossils turn out to have longer fossil ranges than first thought.[52]Stratigraphy and biostratigraphy can in general provide only relative dating (Awas beforeB), which is often sufficient for studying evolution. However, this is difficult for some time periods, because of the problems involved in matching up rocks of the same age across differentcontinents.[52]

Family-tree relationships may also help to narrow down the date when lineages first appeared. For instance, if fossils of B or C date to X million years ago and the calculated "family tree" says A was an ancestor of B and C, then A must have evolved more than X million years ago.

It is also possible to estimate how long ago two living clades diverged – i.e. approximately how long ago their last common ancestor must have lived – by assuming that DNAmutationsaccumulate at a constant rate. These "molecular clocks",however, are fallible, and provide only a very approximate timing: for example, they are not sufficiently precise and reliable for estimating when the groups that feature in theCambrian explosionfirst evolved,[53]and estimates produced by different techniques may vary by a factor of two.[18]

History of life

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This wrinkled "elephant skin" texture is atrace fossilof a non-stromatolitemicrobial mat.The image shows the location, in theBurgsvik bedsof Sweden, where the texture was first identified as evidence of a microbial mat.[54]
Main article:Evolutionary history of life
Further information:Timeline of evolutionary history of life

Earth formed about4,570million years agoand, after a collision that formed theMoonabout 40 million years later, may have cooled quickly enough to have oceans and an atmosphere about4,440million years ago.[55][56]There is evidence on the Moon of aLate Heavy Bombardmentby asteroids from4,000 to 3,800million years ago.If, as seems likely, such a bombardment struck Earth at the same time, the first atmosphere and oceans may have been stripped away.[57]

Paleontology traces the evolutionary history of life back to over3,000million years ago,possibly as far as3,800million years ago.[58]The oldest clear evidence of life on Earth dates to3,000million years ago,although there have been reports, often disputed, offossilbacteria from3,400million years agoand of geochemical evidence for the presence of life3,800million years ago.[16][59]Some scientists have proposed that life on Earth was"seeded" from elsewhere,[60][61][62]but most research concentrates on various explanations of how life could havearisen independentlyon Earth.[63]

For about 2,000 million yearsmicrobial mats,multi-layered colonies of different bacteria, were the dominant life on Earth.[64]The evolution ofoxygenic photosynthesisenabled them to play the major role in theoxygenation of the atmosphere[29]from about2,400million years ago.This change in the atmosphere increased their effectiveness as nurseries of evolution.[65]Whileeukaryotes,cells with complex internal structures, may have been present earlier, their evolution speeded up when they acquired the ability to transform oxygen from apoisonto a powerful source ofmetabolicenergy. This innovation may have come from primitive eukaryotes capturing oxygen-powered bacteria asendosymbiontsand transforming them intoorganellescalledmitochondria.[58][66]The earliest evidence of complex eukaryotes with organelles (such as mitochondria) dates from1,850million years ago.[30]

Opabiniasparked modern interest in theCambrian explosion.

Multicellularlife is composed only of eukaryotic cells, and the earliest evidence for it is theFrancevillian Group Fossilsfrom2,100million years ago,[67]although specialisation of cells for different functions first appears between1,430million years ago(a possible fungus) and1,200million years ago(a probablered alga).Sexual reproductionmay be a prerequisite for specialisation of cells, as an asexual multicellular organism might be at risk of being taken over by rogue cells that retain the ability to reproduce.[68][69]

The earliest known animals arecnidariansfrom about580million years ago,but these are so modern-looking that must be descendants of earlier animals.[70]Early fossils of animals are rare because they had not developedmineralised,easily fossilized hard parts until about548million years ago.[71]The earliest modern-lookingbilateriananimals appear in the EarlyCambrian,along with several "weird wonders" that bear little obvious resemblance to any modern animals. There is a long-running debate about whether thisCambrian explosionwas truly a very rapid period of evolutionary experimentation; alternative views are that modern-looking animals began evolving earlier but fossils of their precursors have not yet been found, or that the "weird wonders" areevolutionary "aunts" and "cousins"of modern groups.[72]Vertebratesremained a minor group until the first jawed fish appeared in the LateOrdovician.[73][74]

At about 13 centimetres (5.1 in) the Early CretaceousYanoconodonwas longer than the average mammal of the time.[75]

The spread of animals and plants from water to land required organisms to solve several problems, including protection against drying out and supporting themselves againstgravity.[76][77][78][79]The earliest evidence of land plants and land invertebrates date back to about476million years agoand490million years agorespectively.[78][80]Those invertebrates, as indicated by their trace and body fossils, were shown to be arthropods known aseuthycarcinoids.[81]The lineage that produced land vertebrates evolved later but very rapidly between370million years agoand360million years ago;[82]recent discoveries have overturned earlier ideas about the history and driving forces behind their evolution.[83]Land plants were so successful that their detritus caused anecological crisisin the LateDevonian,until the evolution of fungi that could digest dead wood.[32]

Birds are the only surviving dinosaurs.[84]

During thePermianperiod,synapsids,including the ancestors ofmammals,may have dominated land environments,[85]but this ended with thePermian–Triassic extinction event251million years ago,which came very close to wiping out all complex life.[86]The extinctions were apparently fairly sudden, at least among vertebrates.[87]During the slow recovery from this catastrophe a previously obscure group,archosaurs,became the most abundant and diverse terrestrial vertebrates. One archosaur group, the dinosaurs, were the dominant land vertebrates for the rest of theMesozoic,[88]and birds evolved from one group of dinosaurs.[84]During this time mammals' ancestors survived only as small, mainly nocturnalinsectivores,which may have accelerated the development of mammalian traits such asendothermyand hair.[89]After theCretaceous–Paleogene extinction event66million years ago[90]killed off all the dinosaurs except the birds, mammals increased rapidly in size and diversity, and some took to the air and the sea.[91][92][93]

Fossil evidence indicates thatflowering plantsappeared and rapidly diversified in the EarlyCretaceousbetween130million years agoand90million years ago.[94]Their rapid rise to dominance of terrestrial ecosystems is thought to have been propelled bycoevolutionwithpollinatinginsects.[95]Social insectsappeared around the same time and, although they account for only small parts of the insect "family tree", now form over 50% of the total mass of all insects.[96]

Humans evolved from a lineage of upright-walkingapeswhose earliest fossils date from over6million years ago.[97]Although early members of this lineage hadchimp-sized brains, about 25% as big as modern humans', there are signs of a steady increase in brain size after about3million years ago.[98]There is a long-running debate about whethermodernhumans are descendants of asingle small population in Africa,which then migrated all over the world less than 200,000 years ago and replaced previoushomininespecies, orarose worldwide at the same timeas a result ofinterbreeding.[99]

Mass extinctions

[edit]
CambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Marine extinction intensity duringPhanerozoic
%
Millions of years ago
CambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Apparent extinction intensity, i.e. the fraction ofgeneragoing extinct at any given time, as reconstructed from thefossil record(graph not meant to include recent epoch ofHolocene extinction event)
Main article:Mass extinction

Life on earth has suffered occasional mass extinctions at least since542million years ago.Despite their disastrous effects, mass extinctions have sometimes accelerated the evolution of life on earth. When dominance of anecological nichepasses from one group of organisms to another, this is rarely because the new dominant group outcompetes the old, but usually because an extinction event allows a new group, which may possess an advantageous trait, to outlive the old and move into its niche.[100][101][102]

The fossil record appears to show that the rate of extinction is slowing down, with both the gaps between mass extinctions becoming longer and the average and background rates of extinction decreasing. However, it is not certain whether the actual rate of extinction has altered, since both of these observations could be explained in several ways:[103]

  • The oceans may have become more hospitable to life over the last 500 million years and less vulnerable to mass extinctions:dissolved oxygenbecame more widespread and penetrated to greater depths; the development of life on land reduced the run-off of nutrients and hence the risk ofeutrophicationandanoxic events;marine ecosystems became more diversified so thatfood chainswere less likely to be disrupted.[104][105]
  • Reasonably completefossilsare very rare: most extinct organisms are represented only by partial fossils, and complete fossils are rarest in the oldest rocks. So paleontologists have mistakenly assigned parts of the same organism to differentgenera,which were often defined solely to accommodate these finds – the story ofAnomalocarisis an example of this.[106]The risk of this mistake is higher for older fossils because these are often unlike parts of any living organism. Many "superfluous" genera are represented by fragments that are not found again, and these "superfluous" genera are interpreted as becoming extinct very quickly.[103]
"Well-defined" genera
Trend line
Other mass extinctions
Million years ago
Thousands of genera
Phanerozoic biodiversity as shown by the fossil record

Biodiversityin the fossil record, which is

"the number of distinct genera alive at any given time; that is, those whose first occurrence predates and whose last occurrence postdates that time"[107]

shows a different trend: a fairly swift rise from542 to 400million years ago,a slight decline from400 to 200million years ago,in which the devastatingPermian–Triassic extinction eventis an important factor, and a swift rise from200million years agoto the present.[107]

History

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Main article:History of paleontology
Further information:Timeline of paleontology
This illustration of anIndian elephantjaw and amammothjaw (top) is fromCuvier's 1796 paper on living and fossil elephants.

Although paleontology became established around 1800, earlier thinkers had noticed aspects of thefossilrecord. The ancient GreekphilosopherXenophanes(570–480 BCE) concluded from fossil sea shells that some areas of land were once under water.[108]During theMiddle Agesthe Persian naturalistIbn Sina,known asAvicennain Europe, discussed fossils and proposed a theory of petrifying fluids on whichAlbert of Saxonyelaborated in the 14th century.[108]The Chinese naturalistShen Kuo(1031–1095) proposed a theory of climate change based on the presence ofpetrifiedbambooin regions that in his time were too dry for bamboo.[109]

Inearly modern Europe,the systematic study of fossils emerged as an integral part of the changes innatural philosophythat occurred during theAge of Reason.In the Italian Renaissance,Leonardo da Vincimade various significant contributions to the field as well as depicted numerous fossils. Leonardo's contributions are central to the history of paleontology because he established a line of continuity between the two main branches of paleontology – ichnology and body fossil paleontology.[110][111][112]He identified the following:[110]

  1. The biogenic nature of ichnofossils, i.e. ichnofossils were structures left by living organisms;
  2. The utility of ichnofossils as paleoenvironmental tools – certain ichnofossils show the marine origin of rock strata;
  3. The importance of the neoichnological approach – recent traces are a key to understanding ichnofossils;
  4. The independence and complementary evidence of ichnofossils and body fossils – ichnofossils are distinct from body fossils, but can be integrated with body fossils to provide paleontological information
Georges Cuvier's 1812 sketch of a skeletal and muscle reconstruction ofAnoplotheriumcommune.This sketch was amongst the first instances of prehistoric animal reconstructions based on fossil remains.

At the end of the 18th centuryGeorges Cuvier's work establishedcomparative anatomyas a scientific discipline and, by proving that some fossil animals resembled no living ones, demonstrated that animals could becomeextinct,leading to the emergence of paleontology.[113]The expanding knowledge of the fossil record also played an increasing role in the development of geology, particularlystratigraphy.[114]Cuvier proved that the different levels of deposits represented different time periods in the early 19th century. The surface-level deposits in the Americas contained later mammals like the megatheriid ground slothMegatheriumand themammutidproboscideanMammut(later known informally as a "mastodon" ), which were some of the earliest-named fossil mammal genera with official taxonomic authorities. They today are known to date to theNeogene-Quaternary.In deeper-level deposits in western Europe are early-aged mammals such as thepalaeothereperissodactylPalaeotheriumand theanoplotheriidartiodactylAnoplotherium,both of which were described earliest after the former two genera, which today are known to date to thePaleogeneperiod. Cuvier figured out that even older than the two levels of deposits with extinct large mammals is one that contained an extinct "crocodile-like" marine reptile, which eventually came to be known as themosasauridMosasaurusof theCretaceousperiod.[115]

First mention of the wordpalæontologie,as coined in January 1822 byHenri Marie Ducrotay de Blainvillein hisJournal de physique

The first half of the 19th century saw geological and paleontological activity become increasingly well organised with the growth of geologic societies and museums[116][117]and an increasing number of professional geologists and fossil specialists. Interest increased for reasons that were not purely scientific, as geology and paleontology helped industrialists to find and exploit natural resources such as coal.[108] This contributed to a rapid increase in knowledge about the history of life on Earth and to progress in the definition of thegeologic time scale,largely based on fossil evidence. Although she was rarely recognised by the scientific community,[118]Mary Anningwas a significant contributor to the field of palaeontology during this period; she uncovered multiple novelMesozoicreptile fossils and deducted that what were then known asbezoarstones are in factfossilised faeces.[119]In 1822Henri Marie Ducrotay de Blainville,editor ofJournal de Physique,coined the word "palaeontology" to refer to the study of ancient living organisms through fossils.[120]As knowledge of life's history continued to improve, it became increasingly obvious that there had been some kind of successive order to the development of life. This encouraged early evolutionary theories on thetransmutation of species.[121] AfterCharles DarwinpublishedOrigin of Speciesin 1859, much of the focus of paleontology shifted to understandingevolutionarypaths, includinghuman evolution,and evolutionary theory.[121]

Haikouichthys,from about518million years agoin China, may be the earliest known fish[122]

The last half of the 19th century saw a tremendous expansion in paleontological activity, especially in North America.[123]The trend continued in the 20th century with additional regions of the Earth being opened to systematic fossil collection. Fossils found in China near the end of the 20th century have been particularly important as they have provided new information about the earliest evolution of animals, early fish, dinosaurs and the evolution of birds.[124]The last few decades of the 20th century saw a renewed interest inmass extinctionsand their role in the evolution of life on Earth.[125]There was also a renewed interest in theCambrian explosionthat apparently saw the development of the body plans of most animalphyla.The discovery of fossils of theEdiacaran biotaand developments inpaleobiologyextended knowledge about the history of life back far before the Cambrian.[72]

Increasing awareness ofGregor Mendel's pioneering work ingeneticsled first to the development ofpopulation geneticsand then in the mid-20th century to themodern evolutionary synthesis,which explainsevolutionas the outcome of events such asmutationsandhorizontal gene transfer,which providegenetic variation,withgenetic driftandnatural selectiondriving changes in this variation over time.[125]Within the next few years the role and operation ofDNAin genetic inheritance were discovered, leading to what is now known as the"Central Dogma" of molecular biology.[126]In the 1960smolecular phylogenetics,the investigation of evolutionary "family trees" by techniques derived frombiochemistry,began to make an impact, particularly when it was proposed that the human lineage had diverged fromapesmuch more recently than was generally thought at the time.[127]Although this early study comparedproteinsfrom apes and humans, most molecular phylogenetics research is now based on comparisons ofRNAandDNA.[128]

[edit]

Books catered to the general public on paleontology include:

See also

[edit]

Notes

[edit]
  1. ^Outside the United States
  2. ^In 1822,Henri Marie Ducrotay de Blainvilleused the French termpalœontologie.[1]In 1838,Charles Lyellused the English termpalæontologyinElements of Geology.[2]

References

[edit]
  1. ^abJournal de physique, de chimie, d'histoire naturelle et des arts.Paris: Cuchet. 1822. p.liv.
  2. ^Lyell, Charles (1838).Elements of geology.London: J. Murray. p.281.
  3. ^"paleontology".Online Etymology Dictionary.Archivedfrom the original on March 7, 2013.
  4. ^Doolittle, W. Ford;Worm, Boris(February 2000)."Uprooting the tree of life"(PDF).Scientific American.282(6): 90–95.Bibcode:2000SciAm.282b..90D.doi:10.1038/scientificamerican0200-90.PMID10710791.Archived fromthe original(PDF)on July 15, 2011.
  5. ^abcdeCowen, R. (2000).History of Life(3rd ed.). Blackwell Science. pp. xi, 47–50, 61.ISBN0-632-04444-6.
  6. ^Laporte, L.F. (October 1988). "What, after All, Is Paleontology?".PALAIOS.3(5): 453.Bibcode:1988Palai...3..453L.doi:10.2307/3514718.JSTOR3514718.
  7. ^Laudan, R. (1992)."What's so Special about the Past?".In Nitecki, M.H.; Nitecki, D.V. (eds.).History and Evolution.SUNY Press. p. 58.ISBN0-7914-1211-3.To structure my discussion of the historical sciences, I shall borrow a way of analyzing them from the great Victorian philosopher of science, William Whewell [...]. [...] while his analysis of the historical sciences (or as Whewell termed them, the palaetiological sciences) will doubtless need to be modified, it provides a good starting point. Among them he numbered geology, paleontology, cosmogony, philology, and what we would term archaeology and history.
  8. ^abcCleland, C.E.(September 2002)."Methodological and Epistemic Differences between Historical Science and Experimental Science".Philosophy of Science.69(3): 474–96.doi:10.1086/342453.S2CID224835750.Archived fromthe originalon October 3, 2008.RetrievedSeptember 17,2008.
  9. ^Laudan, R. (1992)."What's so Special about the Past?".In Nitecki, M.H.; Nitecki, D.V. (eds.).History and Evolution.SUNY Press. p. 58.ISBN0-7914-1211-3.[Whewell] distinguished three tasks for such a historical science (1837 [...]): ' the Description of the facts and phenomena; – the general Theory of the causes of change appropriate to the case; – and the Application of the theory to the facts.'
  10. ^ Perreault, Charles (2019). "The Search for Smoking Guns".The Quality of the Archaeological Record.Chicago: University of Chicago Press. p. 5.ISBN978-0226631011.RetrievedJanuary 9,2020.Historical scientists successfully learn about the past by employing a 'smoking-gun' approach. They start by formulating multiple, mutually exclusive hypotheses and then search for a "smoking gun" that discriminates between these hypotheses [...].
  11. ^ "'Historical science' vs. 'experimental science'".National Center for Science Education. October 25, 2019.RetrievedJanuary 9,2020.Philosophers of science draw a distinction between research directed towards identifying laws and research which seeks to determine how particular historical events occurred. They do not claim, however, that the line between these sorts of science can be drawn neatly, and certainly do not agree that historical claims are any less empirically verifiable than other sorts of claims. [...] 'we can separate their two enterprises by distinguishing means from ends. The astronomer's problem is a historical one because the goal is to infer the properties of a particular object; the astronomer uses laws only as a means. Particle physics, on the other hand, is a nomothetic discipline because the goal is to infer general laws; descriptions of particular objects are only relevant as a means.'
  12. ^"paleontology | science".Encyclopædia Britannica.Archivedfrom the original on August 24, 2017.RetrievedAugust 24,2017.
  13. ^McGraw-Hill Encyclopedia of Science & Technology.McGraw-Hill. 2002. p.58.ISBN0-07-913665-6.
  14. ^Laudan, R. (1992). "What's so Special about the Past?". In Nitecki, M.H.; Nitecki, D.V. (eds.).History and Evolution.SUNY Press. p. 57.ISBN0-7914-1211-3.
  15. ^"How does paleontology differ from anthropology and archaeology?".University of California Museum of Paleontology. Archived fromthe originalon September 16, 2008.RetrievedSeptember 17,2008.
  16. ^abcBrasier, M.;McLoughlin, N.; Green, O. & Wacey, D. (June 2006)."A fresh look at the fossil evidence for early Archaean cellular life"(PDF).Philosophical Transactions of the Royal Society B.361(1470): 887–902.doi:10.1098/rstb.2006.1835.PMC1578727.PMID16754605.Archived(PDF)from the original on September 11, 2008.RetrievedAugust 30,2008.
  17. ^abTwitchett R.J.; Looy C.V.; Morante R.; Visscher H.; Wignall P.B. (2001). "Rapid and synchronous collapse of marine and terrestrial ecosystems during the end-Permian biotic crisis".Geology.29(4): 351–54.Bibcode:2001Geo....29..351T.doi:10.1130/0091-7613(2001)029<0351:RASCOM>2.0.CO;2.S2CID129908787.
  18. ^abPeterson, Kevin J. & Butterfield, N.J. (2005)."Origin of the Eumetazoa: Testing ecological predictions of molecular clocks against the Proterozoic fossil record".Proceedings of the National Academy of Sciences.102(27): 9547–52.Bibcode:2005PNAS..102.9547P.doi:10.1073/pnas.0503660102.PMC1172262.PMID15983372.
  19. ^Hutchinson, J.R. & Garcia, M. (February 28, 2002)."Tyrannosauruswas not a fast runner ".Nature.415(6875): 1018–21.Bibcode:2002Natur.415.1018H.doi:10.1038/4151018a.PMID11875567.S2CID4389633. Summary in press releaseNo Olympian: Analysis hintsT. Rexran slowly, if at allArchivedApril 15, 2008, at theWayback Machine
  20. ^Meers, M.B. (August 2003). "Maximum bite force and prey size ofTyrannosaurus rexand their relationships to the inference of feeding behavior ".Historical Biology.16(1): 1–12.doi:10.1080/0891296021000050755.S2CID86782853.
  21. ^"The Four Winged Dinosaur: Wind Tunnel Test".Nova.RetrievedJune 5,2010.
  22. ^Garwood, Russell J.; Rahman, Imran A.; Sutton, Mark D. A. (2010)."From clergymen to computers: the advent of virtual palaeontology".Geology Today.26(3): 96–100.Bibcode:2010GeolT..26...96G.doi:10.1111/j.1365-2451.2010.00753.x.S2CID53657220.RetrievedJune 16,2015.
  23. ^Mark Sutton; Imran Rahman; Russell Garwood (2013).Techniques for Virtual Palaeontology.Wiley.ISBN978-1-118-59125-3.
  24. ^Bruner, Emiliano (November 2004). "Geometric morphometrics and palaeoneurology: brain shape evolution in the genus Homo".Journal of Human Evolution.47(5): 279–303.Bibcode:2004JHumE..47..279B.doi:10.1016/j.jhevol.2004.03.009.PMID15530349.
  25. ^Cady, S.L. (April 1998). "Astrobiology: A New Frontier for 21st Century Paleontologists".PALAIOS.13(2): 95–97.Bibcode:1998Palai..13...95C.doi:10.2307/3515482.JSTOR3515482.PMID11542813.
  26. ^Plotnick, R.E."A Somewhat Fuzzy Snapshot of Employment in Paleontology in the United States".Palaeontologia Electronica.11(1). Coquina Press.ISSN1094-8074.Archivedfrom the original on May 18, 2008.RetrievedSeptember 17,2008.
  27. ^ab"What is Paleontology?".University of California Museum of Paleontology. Archived fromthe originalon August 3, 2008.RetrievedSeptember 17,2008.
  28. ^Kitchell, J.A. (1985)."Evolutionary Paleocology: Recent Contributions to Evolutionary Theory".Paleobiology.11(1): 91–104.Bibcode:1985Pbio...11...91K.doi:10.1017/S0094837300011428.S2CID88584416.Archived fromthe originalon August 3, 2008.RetrievedSeptember 17,2008.
  29. ^abHoehler, T.M.; Bebout, B.M. & Des Marais, D.J. (July 19, 2001). "The role of microbial mats in the production of reduced gases on the early Earth".Nature.412(6844): 324–27.Bibcode:2001Natur.412..324H.doi:10.1038/35085554.PMID11460161.S2CID4365775.
  30. ^abHedges, S.B.; Blair, J.E; Venturi, M.L. & Shoe, J.L. (January 2004)."A molecular timescale of eukaryote evolution and the rise of complex multicellular life".BMC Evolutionary Biology.4:2.doi:10.1186/1471-2148-4-2.PMC341452.PMID15005799.
  31. ^"Paleoclimatology".Ohio State University. Archived fromthe originalon November 9, 2007.RetrievedSeptember 17,2008.
  32. ^abAlgeo, T.J. & Scheckler, S.E. (1998)."Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events".Philosophical Transactions of the Royal Society B.353(1365): 113–30.doi:10.1098/rstb.1998.0195.PMC1692181.
  33. ^"Biostratigraphy: William Smith".Archived fromthe originalon July 24, 2008.RetrievedSeptember 17,2008.
  34. ^"Biogeography: Wallace and Wegener (1 of 2)".University of California Museum of Paleontology and University of California at Berkeley. Archived fromthe originalon May 15, 2008.RetrievedSeptember 17,2008.
  35. ^ab"What is paleontology?".University of California Museum of Paleontology. Archived fromthe originalon September 16, 2008.RetrievedSeptember 17,2008.
  36. ^Benton M.J.; Wills M.A.; Hitchin R. (2000)."Quality of the fossil record through time"(PDF).Nature.403(6769): 534–37.Bibcode:2000Natur.403..534B.doi:10.1038/35000558.PMID10676959.S2CID4407172.
    Non-technicalsummaryArchivedAugust 9, 2007, at theWayback Machine
  37. ^Butterfield, N.J. (2003)."Exceptional Fossil Preservation and the Cambrian Explosion".Integrative and Comparative Biology.43(1): 166–77.doi:10.1093/icb/43.1.166.PMID21680421.
  38. ^Anderson, L.A. (2023)."A chemical framework for the preservation of fossil vertebrate cells and soft tissues".Earth-Science Reviews.240:104367.Bibcode:2023ESRv..24004367A.doi:10.1016/j.earscirev.2023.104367.
  39. ^Butterfield, N.J. (2001)."Ecology and evolution of Cambrian plankton"(PDF).The Ecology of the Cambrian Radiation.New York: Columbia University Press: 200–16.RetrievedSeptember 27,2007.[permanent dead link]
  40. ^Signor, P.W. (1982)."Sampling bias, gradual extinction patterns and catastrophes in the fossil record".Geological Implications of Impacts of Large Asteroids and Comets on the Earth.Geological Society of America Special Papers.190.Boulder, CO: Geological Society of America: 291–96.doi:10.1130/SPE190-p291.ISBN0-8137-2190-3.A 84–25651 10–42. Archived fromthe originalon July 28, 2020.RetrievedJanuary 1,2008.
  41. ^abFedonkin, M.A.; Gehling, J.G.; Grey, K.; Narbonne, G.M.; Vickers-Rich, P. (2007).The Rise of Animals: Evolution and Diversification of the Kingdom Animalia.JHU Press. pp. 213–16.ISBN978-0-8018-8679-9.
  42. ^e.g.Seilacher, A. (1994). "How valid is Cruziana Stratigraphy?".International Journal of Earth Sciences.83(4): 752–58.Bibcode:1994GeoRu..83..752S.doi:10.1007/BF00251073.S2CID129504434.
  43. ^Brocks, J.J.; Logan, G.A.; Buick, R. & Summons, R.E. (1999). "Archaean molecular fossils and the rise of eukaryotes".Science.285(5430): 1033–36.Bibcode:1999Sci...285.1033B.doi:10.1126/science.285.5430.1033.PMID10446042.S2CID11028394.
  44. ^abBrochu, C.A & Sumrall, C.D. (July 2001)."Phylogenetic Nomenclature and Paleontology"(PDF).Journal of Paleontology.75(4): 754–57.doi:10.1666/0022-3360(2001)075<0754:PNAP>2.0.CO;2.ISSN0022-3360.JSTOR1306999.S2CID85927950.
  45. ^Ereshefsky, M.(2001).The Poverty of the Linnaean Hierarchy: A Philosophical Study of Biological Taxonomy.Cambridge University Press. p. 5.ISBN0-521-78170-1.
  46. ^Garwood, Russell J.; Sharma, Prashant P.; Dunlop, Jason A.;Giribet, Gonzalo(2014)."A Paleozoic Stem Group to Mite Harvestmen Revealed through Integration of Phylogenetics and Development".Current Biology.24(9): 1017–23.Bibcode:2014CBio...24.1017G.doi:10.1016/j.cub.2014.03.039.PMID24726154.
  47. ^Cohen, B.L.; Holmer, L.E. & Luter, C. (2003)."The brachiopod fold: a neglected body plan hypothesis".Palaeontology.46(1): 59–65.Bibcode:2003Palgy..46...59C.doi:10.1111/1475-4983.00287.
  48. ^abMartin, M.W.; Grazhdankin, D.V.; Bowring, S.A.; Evans, D.A.D.;Fedonkin, M.A.;Kirschvink, J.L.(May 5, 2000). "Age of Neoproterozoic Bilaterian Body and Trace Fossils, White Sea, Russia: Implications for Metazoan Evolution".Science(abstract).288(5467): 841–45.Bibcode:2000Sci...288..841M.doi:10.1126/science.288.5467.841.PMID10797002.S2CID1019572.
  49. ^Pufahl, P.K.; Grimm, K.A.; Abed, A.M. & Sadaqah, R.M.Y. (October 2003). "Upper Cretaceous (Campanian) phosphorites in Jordan: implications for the formation of a south Tethyan phosphorite giant".Sedimentary Geology.161(3–4): 175–205.Bibcode:2003SedG..161..175P.doi:10.1016/S0037-0738(03)00070-8.
  50. ^"Geologic Time: Radiometric Time Scale".U.S. Geological Survey.Archivedfrom the original on September 21, 2008.RetrievedSeptember 20,2008.
  51. ^Löfgren, A. (2004). "The conodont fauna in the Middle OrdovicianEoplacognathus pseudoplanusZone of Baltoscandia ".Geological Magazine.141(4): 505–24.Bibcode:2004GeoM..141..505L.doi:10.1017/S0016756804009227.S2CID129600604.
  52. ^abGehling, James; Jensen, Sören; Droser, Mary; Myrow, Paul; Narbonne, Guy (March 2001). "Burrowing below the basal Cambrian GSSP, Fortune Head, Newfoundland".Geological Magazine.138(2): 213–18.Bibcode:2001GeoM..138..213G.doi:10.1017/S001675680100509X.S2CID131211543.
  53. ^Hug, L.A. & Roger, A.J. (2007)."The Impact of Fossils and Taxon Sampling on Ancient Molecular Dating Analyses".Molecular Biology and Evolution.24(8): 889–1897.doi:10.1093/molbev/msm115.PMID17556757.
  54. ^ Manten, A.A. (1966)."Some problematic shallow-marine structures".Marine Geol.4(3): 227–32.Bibcode:1966MGeol...4..227M.doi:10.1016/0025-3227(66)90023-5.hdl:1874/16526.S2CID129854399.Archived fromthe originalon October 21, 2008.RetrievedJune 18,2007.
  55. ^"Early Earth Likely Had Continents And Was Habitable".November 17, 2005. Archived fromthe originalon October 14, 2008.
  56. ^A.J. Cavosie; J.W. Valley; S.A. Wilde & E.I.M.F. (July 15, 2005). "Magmatic δ18O in 4400–3900 Ma detrital zircons: A record of the alteration and recycling of crust in the Early Archean ".Earth and Planetary Science Letters.235(3–4): 663–81.Bibcode:2005E&PSL.235..663C.doi:10.1016/j.epsl.2005.04.028.
  57. ^Dauphas, N.; Robert, F. & Marty, B. (December 2000). "The Late Asteroidal and Cometary Bombardment of Earth as Recorded in Water Deuterium to Protium Ratio".Icarus.148(2): 508–12.Bibcode:2000Icar..148..508D.doi:10.1006/icar.2000.6489.S2CID85555707.
  58. ^abGarwood, Russell J. (2012)."Patterns In Palaeontology: The first 3 billion years of evolution".Palaeontology Online.2(11): 1–14.Archivedfrom the original on June 26, 2015.RetrievedJune 25,2015.
  59. ^Schopf, J. (2006)."Fossil evidence of Archaean life".Philos Trans R Soc Lond B Biol Sci.361(1470): 869–85.doi:10.1098/rstb.2006.1834.PMC1578735.PMID16754604.
  60. ^Arrhenius, S. (1903). "The Propagation of Life in Space".Die Umschau.7:32.Bibcode:1980qel..book...32A.Reprinted inGoldsmith, D., ed. (September 1982).The Quest for Extraterrestrial Life.University Science Books.ISBN0-19-855704-3.
  61. ^Hoyle, F. &Wickramasinghe, C.(1979). "On the Nature of Interstellar Grains".Astrophysics and Space Science.66(1): 77–90.Bibcode:1979Ap&SS..66...77H.doi:10.1007/BF00648361.S2CID115165958.
  62. ^Crick, F.H.; Orgel, L.E. (1973). "Directed Panspermia".Icarus.19(3): 341–48.Bibcode:1973Icar...19..341C.doi:10.1016/0019-1035(73)90110-3.
  63. ^Peretó, J. (2005)."Controversies on the origin of life"(PDF).Int. Microbiol.8(1): 23–31.PMID15906258.Archived fromthe original(PDF)on August 24, 2015.RetrievedOctober 7,2007.
  64. ^Krumbein, W.E.; Brehm, U.; Gerdes, G.; Gorbushina, A.A.; Levit, G. & Palinska, K.A. (2003). "Biofilm, Biodictyon, Biomat Microbialites, Oolites, Stromatolites, Geophysiology, Global Mechanism, Parahistology". In Krumbein, W.E.; Paterson, D.M. & Zavarzin, G.A. (eds.).Fossil and Recent Biofilms: A Natural History of Life on Earth(PDF).Kluwer Academic. pp. 1–28.ISBN1-4020-1597-6.Archived fromthe original(PDF)on January 6, 2007.RetrievedJuly 9,2008.
  65. ^Nisbet, E.G. & Fowler, C.M.R. (December 7, 1999)."Archaean metabolic evolution of microbial mats".Proceedings of the Royal Society B.266(1436): 2375.doi:10.1098/rspb.1999.0934.PMC1690475.
  66. ^Gray M.W.; Burger G.; Lang B.F. (March 1999)."Mitochondrial evolution".Science.283(5407): 1476–81.Bibcode:1999Sci...283.1476G.doi:10.1126/science.283.5407.1476.PMC3428767.PMID10066161.
  67. ^El Albani, Abderrazak;Bengtson, Stefan;Canfield, Donald E.;Bekker, Andrey; Macchiarelli, Reberto; Mazurier, Arnaud; Hammarlund, Emma U.; Boulvais, Philippe; et al. (July 2010). "Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago".Nature.466(7302): 100–04.Bibcode:2010Natur.466..100A.doi:10.1038/nature09166.PMID20596019.S2CID4331375.
  68. ^Butterfield, N.J. (September 2000)."Bangiomorpha pubescensn. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes ".Paleobiology.26(3): 386–404.Bibcode:2000Pbio...26..386B.doi:10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;2.ISSN0094-8373.S2CID36648568.Archivedfrom the original on March 7, 2007.RetrievedSeptember 2,2008.
  69. ^Butterfield, N.J. (2005)."Probable Proterozoic fungi".Paleobiology.31(1): 165–82.Bibcode:2005Pbio...31..165B.doi:10.1666/0094-8373(2005)031<0165:PPF>2.0.CO;2.ISSN0094-8373.S2CID86332371.Archivedfrom the original on January 29, 2009.RetrievedSeptember 2,2008.
  70. ^Chen, J.-Y.; Oliveri, P.; Gao, F.; Dornbos, S.Q.; Li, C.-W.; Bottjer, D.J. & Davidson, E.H. (August 2002)."Precambrian Animal Life: Probable Developmental and Adult Cnidarian Forms from Southwest China"(PDF).Developmental Biology.248(1): 182–96.doi:10.1006/dbio.2002.0714.PMID12142030.Archived fromthe original(PDF)on September 11, 2008.RetrievedSeptember 3,2008.
  71. ^Bengtson, S. (2004). Lipps, J.H.; Waggoner, B.M. (eds.)."Early Skeletal Fossils"(PDF).The Paleontological Society Papers.10 Neoproterozoic–Cambrian Biological Revolutions: 67–78.doi:10.1017/S1089332600002345.Archived fromthe original(PDF)on March 3, 2009.RetrievedJuly 18,2008.
  72. ^abMarshall, C.R. (2006). "Explaining the Cambrian" Explosion "of Animals".Annu. Rev. Earth Planet. Sci.34:355–84.Bibcode:2006AREPS..34..355M.doi:10.1146/annurev.earth.33.031504.103001.S2CID85623607.
  73. ^Conway Morris, S. (August 2, 2003)."Once we were worms".New Scientist.179(2406): 34. Archived fromthe originalon July 25, 2008.RetrievedSeptember 5,2008.
  74. ^Sansom I.J., Smith, M.M. & Smith, M.P. (2001). "The Ordovician radiation of vertebrates". In Ahlberg, P.E. (ed.).Major Events in Early Vertebrate Evolution.Taylor and Francis. pp. 156–71.ISBN0-415-23370-4.{{cite book}}:CS1 maint: multiple names: authors list (link)
  75. ^Luo, Z.; Chen, P.; Li, G. & Chen, M. (March 2007)."A new eutriconodont mammal and evolutionary development in early mammals"(PDF).Nature.446(7133): 288–93.Bibcode:2007Natur.446..288L.doi:10.1038/nature05627.PMID17361176.S2CID4329583.
  76. ^Russell Garwood &Gregory Edgecombe(2011)."Early terrestrial animals, evolution and uncertainty".Evolution: Education and Outreach.4(3): 489–501.doi:10.1007/s12052-011-0357-y.
  77. ^Selden, P.A. (2001). "Terrestrialization of Animals". In Briggs, D.E.G.; Crowther, P.R. (eds.).Palaeobiology II: A Synthesis.Blackwell. pp. 71–74.ISBN0-632-05149-3.
  78. ^abKenrick, P. & Crane, P.R. (September 1997)."The origin and early evolution of plants on land"(PDF).Nature.389(6646): 33.Bibcode:1997Natur.389...33K.doi:10.1038/37918.S2CID3866183.Archived fromthe original(PDF)on December 17, 2010.RetrievedNovember 11,2010.
  79. ^Laurin, M.(2010).How Vertebrates Left the Water.Berkeley, California: University of California Press.ISBN978-0-520-26647-6.
  80. ^MacNaughton, R.B.; Cole, J.M.; Dalrymple, R.W.; Braddy, S.J.; Briggs, D.E.G. & Lukie, T.D. (May 2002). "First steps on land: Arthropod trackways in Cambrian-Ordovician eolian sandstone, southeastern Ontario, Canada".Geology.30(5): 391–94.Bibcode:2002Geo....30..391M.doi:10.1130/0091-7613(2002)030<0391:FSOLAT>2.0.CO;2.ISSN0091-7613.
  81. ^Collette, J.H.; Gass, K.C. & Hagadorn, J.W. (May 2012). "Protichnites eremitaunshelled? Experimental model-based neoichnology and new evidence for a euthycarcinoid affinity for this ichnospecies ".Journal of Paleontology.86(3): 442–54.Bibcode:2012JPal...86..442C.doi:10.1666/11-056.1.S2CID129234373.
  82. ^Gordon, M.S; Graham, J.B. & Wang, T. (September–October 2004). "Revisiting the Vertebrate Invasion of the Land".Physiological and Biochemical Zoology.77(5): 697–99.doi:10.1086/425182.S2CID83750933.
  83. ^Clack, J.A.(November 2005)."Getting a Leg Up on Land".Scientific American.RetrievedSeptember 6,2008.
  84. ^abPadian, Kevin (2004). "Basal Avialae". InWeishampel, David B.;Dodson, Peter;Osmólska, Halszka (eds.).The Dinosauria(Second ed.). Berkeley: University of California Press. pp. 210–31.ISBN0-520-24209-2.
  85. ^Sidor, C.A.;O'Keefe, F.R.; Damiani, R.; Steyer, J.S.; Smith, R.M.H.; Larsson, H.C.E.; Sereno, P.C.; Ide, O & Maga, A. (April 2005)."Permian tetrapods from the Sahara show climate-controlled endemism in Pangaea"(PDF).Nature.434(7035): 886–89.Bibcode:2005Natur.434..886S.doi:10.1038/nature03393.PMID15829962.S2CID4416647.
  86. ^Benton M.J. (2005).When Life Nearly Died: The Greatest Mass Extinction of All Time.Thames & Hudson.ISBN978-0-500-28573-2.
  87. ^Ward, P.D.; Botha, J.; Buick, R.; Kock, M.O.; et al. (2005)."Abrupt and gradual extinction among late Permian land vertebrates in the Karoo Basin, South Africa"(PDF).Science.307(5710): 709–14.Bibcode:2005Sci...307..709W.doi:10.1126/science.1107068.PMID15661973.S2CID46198018.Archived fromthe original(PDF)on August 13, 2012.RetrievedOctober 25,2017.
  88. ^Benton, M.J. (March 1983)."Dinosaur Success in the Triassic: a Noncompetitive Ecological Model"(PDF).Quarterly Review of Biology.58(1): 29–55.doi:10.1086/413056.S2CID13846947.Archived fromthe original(PDF)on September 11, 2008.RetrievedSeptember 8,2008.
  89. ^Ruben, J.A. & Jones, T.D. (2000)."Selective Factors Associated with the Origin of Fur and Feathers".American Zoologist.40(4): 585–96.doi:10.1093/icb/40.4.585.
  90. ^Renne, Paul R.;Deino, Alan L.; Hilgen, Frederik J.; Kuiper, Klaudia F.; Mark, Darren F.; Mitchell, William S.; Morgan, Leah E.; Mundil, Roland; Smit, Jan (February 7, 2013)."Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary".Science.339(6120): 684–87.Bibcode:2013Sci...339..684R.doi:10.1126/science.1230492.PMID23393261.S2CID6112274.
  91. ^Alroy J. (March 1999)."The fossil record of North American mammals: evidence for a Paleocene evolutionary radiation".Systematic Biology.48(1): 107–18.doi:10.1080/106351599260472.PMID12078635.
  92. ^Simmons, N.B.; Seymour, K.L.; Habersetzer, J. & Gunnell, G.F. (February 2008)."Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation"(PDF).Nature.451(7180): 818–21.Bibcode:2008Natur.451..818S.doi:10.1038/nature06549.hdl:2027.42/62816.PMID18270539.S2CID4356708.
  93. ^J.G.M.Thewissen;S.I. Madar & S.T. Hussain (1996). "Ambulocetus natans,an Eocene cetacean (Mammalia) from Pakistan ".Courier Forschungsinstitut Senckenberg.191:1–86.
  94. ^Crane, P.R.; Friis, E.M. & Pedersen, K.R. (2000)."The Origin and Early Diversification of Angiosperms".In Gee, H. (ed.).Shaking the Tree: Readings from Nature in the History of Life.University of Chicago Press. pp. 233–50.ISBN0-226-28496-4.
  95. ^Crepet, W.L. (November 2000)."Progress in understanding angiosperm history, success, and relationships: Darwin's abominably" perplexing phenomenon "".Proceedings of the National Academy of Sciences.97(24): 12939–41.Bibcode:2000PNAS...9712939C.doi:10.1073/pnas.97.24.12939.PMC34068.PMID11087846.
  96. ^Wilson, E.O. & Hölldobler, B. (September 2005)."Eusociality: Origin and consequences".Proceedings of the National Academy of Sciences.102(38): 13367–71.Bibcode:2005PNAS..10213367W.doi:10.1073/pnas.0505858102.PMC1224642.PMID16157878.
  97. ^Brunet M., Guy; Pilbeam, F.; Mackaye, H.T.D.; et al. (July 2002)."A new hominid from the Upper Miocene of Chad, Central Africa"(PDF).Nature.418(6894): 145–51.Bibcode:2002Natur.418..145B.doi:10.1038/nature00879.PMID12110880.S2CID1316969.
  98. ^De Miguel, C. & Henneberg, M. (2001). "Variation in hominid brain size: How much is due to method?".HOMO: Journal of Comparative Human Biology.52(1): 3–58.doi:10.1078/0018-442X-00019.PMID11515396.
  99. ^Leakey, Richard(1994).The Origin of Humankind.Science Masters Series. New York: Basic Books. pp. 87–89.ISBN0-465-05313-0.
  100. ^Benton, M.J. (2004)."6. Reptiles of the Triassic".Vertebrate Palaeontology.Blackwell.ISBN0-04-566002-6.RetrievedNovember 17,2008.
  101. ^Sahney, Sarda; Benton, Michael J.; Ferry, Paul A. (August 23, 2010)."Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land".Biology Letters.6(4): 544–547.doi:10.1098/rsbl.2009.1024.PMC2936204.PMID20106856.
  102. ^Van Valkenburgh, B. (1999)."Major patterns in the history of xarnivorous mammals".Annual Review of Earth and Planetary Sciences.27:463–93.Bibcode:1999AREPS..27..463V.doi:10.1146/annurev.earth.27.1.463.
  103. ^abMacLeod, Norman (January 6, 2001)."Extinction!".Archived fromthe originalon April 4, 2008.RetrievedSeptember 11,2008.
  104. ^Martin, R.E. (1995). "Cyclic and secular variation in microfossil biomineralization: clues to the biogeochemical evolution of Phanerozoic oceans".Global and Planetary Change.11(1): 1.Bibcode:1995GPC....11....1M.doi:10.1016/0921-8181(94)00011-2.
  105. ^Martin, R.E. (1996). "Secular increase in nutrient levels through the Phanerozoic: Implications for productivity, biomass, and diversity of the marine biosphere".PALAIOS.11(3): 209–19.Bibcode:1996Palai..11..209M.doi:10.2307/3515230.JSTOR3515230.S2CID67810793.
  106. ^Gould, S.J.(1990).Wonderful Life: The Burgess Shale and the Nature of History.Hutchinson Radius. pp. 194–206.ISBN0-09-174271-4.
  107. ^abRohde, R.A. & Muller, R.A. (March 2005)."Cycles in fossil diversity"(PDF).Nature.434(7030): 208–10.Bibcode:2005Natur.434..208R.doi:10.1038/nature03339.PMID15758998.S2CID32520208.Archived(PDF)from the original on October 3, 2008.RetrievedSeptember 22,2008.
  108. ^abcRudwick, Martin J.S.(1985).The Meaning of Fossils(2nd ed.). The University of Chicago Press. pp. 24, 39, 200–01.ISBN0-226-73103-0.
  109. ^Needham, Joseph(1986).Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth.Caves Books Ltd. p. 614.ISBN0-253-34547-2.
  110. ^abBaucon, A. (2010). "Leonardo da Vinci, the founding father of ichnology".PALAIOS25. Abstract available from theauthor's webpage[self-published source?]
  111. ^Baucon A., Bordy E., Brustur T., Buatois L., Cunningham T., De C., Duffin C., Felletti F., Gaillard C., Hu B., Hu L., Jensen S., Knaust D., Lockley M., Lowe P., Mayor A., Mayoral E., Mikulas R., Muttoni G., Neto de Carvalho C., Pemberton S., Pollard J., Rindsberg A., Santos A., Seike K., Song H., Turner S., Uchman A., Wang Y., Yi-ming G., Zhang L., Zhang W. (2012). "A history of ideas in ichnology". In: Bromley R.G., Knaust D.Trace Fossils as Indicators of Sedimentary Environments. Developments in Sedimentology,vol. 64.Tracemaker.com[self-published source?]
  112. ^Baucon, A. (2010). "Da Vinci'sPaleodictyon:the fractal beauty of traces ".Acta Geologica Polonica,60(1). Accessible from theauthor's homepage[self-published source?]
  113. ^McGowan, Christopher (2001).The Dragon Seekers.Persus Publishing. pp.3–4.ISBN0-7382-0282-7.
  114. ^Palmer, D. (2005).Earth Time: Exploring the Deep Past from Victorian England to the Grand Canyon.Wiley.ISBN978-0470022214.
  115. ^Wallace, David Rains (2004). "Chapter 1: Pachyderms in the Catacombs".Beasts of Eden: Walking Whales, Dawn Horses, and Other Enigmas of Mammal Evolution.University of California Press. pp. 1–13.
  116. ^Grene, Marjorie;David Depew (2004).The Philosophy of Biology: An Episodic History.Cambridge University Press. pp. 128–30.ISBN0-521-64371-6.
  117. ^Bowler, Peter J.; Iwan Rhys Morus (2005).Making Modern Science.The University of Chicago Press. pp. 168–69.ISBN0-226-06861-7.
  118. ^McGowan, Christopher (2001).The Dragon Seekers.Cambridge, MA: Persus Publishing. pp. 14–21.ISBN978-0-7382-0282-2.
  119. ^"Mary Anning: the unsung hero of fossil discovery".www.nhm.ac.uk.RetrievedJanuary 16,2022.
  120. ^Rudwick, Martin J.S.(2008).Worlds Before Adam: The Reconstruction of Geohistory in the Age of Reform.The University of Chicago Press. p. 48.ISBN978-0-226-73128-5.
  121. ^abBuckland, W. & Gould, S.J. (1980).Geology and Mineralogy Considered With Reference to Natural Theology (History of Paleontology).Ayer Company Publishing.ISBN978-0-405-12706-9.
  122. ^Shu, D.G.; Conway Morris, S.; Han, J.; Zhang, Z F.; Yasui, K.; Janvier, P.; Chen, L.; Zhang, X.L.; Liu, J.N.; Li, Y.; Liu, H.-Q. (2003),"Head and backbone of the Early Cambrian vertebrateHaikouichthys",Nature,421(6922): 526–29,Bibcode:2003Natur.421..526S,doi:10.1038/nature01264,PMID12556891,S2CID4401274,archivedfrom the original on November 24, 2015
  123. ^Everhart, Michael J. (2005).Oceans of Kansas: A Natural History of the Western Interior Sea.Indiana University Press. p. 17.ISBN0-253-34547-2.
  124. ^Gee, H., ed. (2001).Rise of the Dragon: Readings from Nature on the Chinese Fossil Record.Chicago; London: University of Chicago Press. p. 276.ISBN0-226-28491-3.
  125. ^abBowler, Peter J.(2003).Evolution: The History of an Idea.University of California Press. pp.351–52,325–39.ISBN0-520-23693-9.
  126. ^Crick, F.H.C. (1955)."On degenerate templates and the adaptor hypothesis"(PDF).Archived fromthe original(PDF)on October 1, 2008.RetrievedOctober 4,2008.
  127. ^Sarich, V.M. & Wilson, A.C. (December 1967). "Immunological time scale for hominid evolution".Science.158(3805): 1200–03.Bibcode:1967Sci...158.1200S.doi:10.1126/science.158.3805.1200.PMID4964406.S2CID7349579.
  128. ^Page, R.D.M. & Holmes, E.C. (1998).Molecular Evolution: A Phylogenetic Approach.Oxford: Blackwell Science. p. 2.ISBN0-86542-889-1.
  129. ^Black, Riley (2022).The Last Days of the Dinosaurs: An Asteroid, Extinction, and the Beginning of Our World(1st ed.). United States: St. Martin's Press.ISBN978-1250271044.
  130. ^Brusatte, Steve(2022).The Rise and Reign of the Mammals: A New History, from the Shadow of the Dinosaurs to Us(1st ed.). United States: Mariner Books.ISBN978-0062951519.
  131. ^Halliday, Thomas (2022).Otherlands: A Journey Through Earth's Extinct Worlds(1st ed.). United States: Random House.ISBN978-0593132883.
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