History of paleontology
Encyclopedia
The history of paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
traces the history of the effort to understand the history of life on Earth by studying the fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
record left behind by living organisms. Since it is concerned with understanding living organisms of the past paleontology can be considered to be a field of biology, but its historical development has been closely tied to geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and the effort to understand the history of the Earth itself.
In ancient times Xenophanes
Xenophanes
of Colophon was a Greek philosopher, theologian, poet, and social and religious critic. Xenophanes life was one of travel, having left Ionia at the age of 25 he continued to travel throughout the Greek world for another 67 years. Some scholars say he lived in exile in Siciliy...
(570-480 BC) wrote about fossil sea shells indicating that land was once under water. During the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
, fossils were discussed by the Persian naturalist, Ibn Sina
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(known as Avicenna in Europe), in The Book of Healing
The Book of Healing
The Book of Healing is a scientific and philosophical encyclopedia written by Abū Alī ibn Sīnā from Asfahana, near Bukhara in Greater Persia. Despite its English title, it is not in fact concerned with medicine...
(1027), which proposed a theory of petrifying fluids that Albert of Saxony
Albert of Saxony
Albert of Saxony may refer to:* Albert of Saxony * Albert I, Duke of Saxony * Albert, Duke of Saxony * Prince Albert of Saxony, Duke of Teschen * Albert of Saxony...
would elaborate on in the 14th century. The Chinese naturalist Shen Kuo
Shen Kuo
Shen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...
(1031–1095) would propose a theory of climate change based on evidence from petrified bamboo.
In early modern Europe
Early modern Europe
Early modern Europe is the term used by historians to refer to a period in the history of Europe which spanned the centuries between the end of the Middle Ages and the beginning of the Industrial Revolution, roughly the late 15th century to the late 18th century...
, the systematic study of fossils emerged as an integral part of the changes in natural philosophy
Natural philosophy
Natural philosophy or the philosophy of nature , is a term applied to the study of nature and the physical universe that was dominant before the development of modern science...
that occurred during the Age of Reason. The nature of fossils and their relationship to life in the past became better understood during the 17th and 18th centuries, and at the end of the 18th century the work of Georges Cuvier
Georges Cuvier
Georges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
ended a long running debate about the reality of extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
and led to the emergence of paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
, in association with comparative anatomy
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
, as a scientific discipline. The expanding knowledge of the fossil record also played an increasing role in the development of geology, particularly stratigraphy
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
.
In 1822 the word "paleontology" was invented by the editor of a French scientific journal to refer to the study of ancient living organisms through fossils, and the first half of the 19th century saw geological and paleontological activity become increasingly well organized with the growth of geologic societies and museums and an increasing number of professional geologists and fossil specialists. This contributed to a rapid increase in knowledge about the past history of life on Earth, and progress towards definition of the geologic time scale
Geologic time scale
The geologic time scale provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth...
largely based on fossil evidence. As knowledge of life's past history continued to improve, it became increasingly obvious that there had been some kind of successive order to the development of life. This would encourage early evolutionary theories on the transmutation of species
Transmutation of species
Transmutation of species was a term used by Jean Baptiste Lamarck in 1809 for his theory that described the altering of one species into another, and the term is often used to describe 19th century evolutionary ideas that preceded Charles Darwin's theory of natural selection...
.
After Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
published Origin of Species in 1859, much of the focus of paleontology shifted to understanding evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary paths, including human evolution
Human evolution
Human evolution refers to the evolutionary history of the genus Homo, including the emergence of Homo sapiens as a distinct species and as a unique category of hominids and mammals...
, and evolutionary theory.
The last half of the 19th century saw a tremendous expansion in paleontological activity, especially in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. The trend continued in the 20th century with additional regions of the Earth being opened to systematic fossil collection, as demonstrated by a series of important discoveries in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
near the end of the century. The last few decades of the 20th century saw a renewed interest in mass extinctions and their role in the evolution of life on Earth. There was also a renewed interest in the Cambrian explosion
Cambrian explosion
The Cambrian explosion or Cambrian radiation was the relatively rapid appearance, around , of most major phyla, as demonstrated in the fossil record, accompanied by major diversification of other organisms, including animals, phytoplankton, and calcimicrobes...
that saw the development of the body plans of most animal phyla. The discovery of fossils of the Ediacaran biota and developments in paleobiology
Paleobiology
Paleobiology is a growing and comparatively new discipline which combines the methods and findings of the natural science biology with the methods and findings of the earth science paleontology...
extended knowledge about the history of life back far before the Cambrian.
Prior to the 17th century
As early as the 6th century BC, the Greek philosopherGreek philosophy
Ancient Greek philosophy arose in the 6th century BCE and continued through the Hellenistic period, at which point Ancient Greece was incorporated in the Roman Empire...
Xenophanes of Colophon (570-480 BC) recognized that some fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
shells were remains of shellfish, which he used to argue that what was at the time dry land was once under the sea. Leonardo da Vinci
Leonardo da Vinci
Leonardo di ser Piero da Vinci was an Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer whose genius, perhaps more than that of any other figure, epitomized the Renaissance...
(1452–1519), in an unpublished notebook, also concluded that some fossil sea shells were the remains of shellfish. However, in both cases, the fossils were complete remains of shellfish species that closely resembled living species, and were therefore easy to classify.
In 1027, the Persian naturalist
Islamic geography
Geography and cartography in medieval Islam refers to the advancement of geography, cartography and the earth sciences in the medieval Islamic civilization....
, Ibn Sina
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(known as Avicenna in Europe), proposed an explanation of how the stoniness
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
of fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s was caused in The Book of Healing
The Book of Healing
The Book of Healing is a scientific and philosophical encyclopedia written by Abū Alī ibn Sīnā from Asfahana, near Bukhara in Greater Persia. Despite its English title, it is not in fact concerned with medicine...
. He modified an idea of Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
's, which explained it in terms of vapor
Vapor
A vapor or vapour is a substance in the gas phase at a temperature lower than its critical point....
ous exhalation
Exhalation
Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....
s. Ibn Sina modified this into the theory of petrifying
Petrifaction
In geology, petrifaction, petrification or silicification is the process by which organic material is converted into stone by impregnation with silica. It is a rare form of fossilization...
fluids (succus lapidificatus), which was elaborated on by Albert of Saxony
Albert of Saxony (philosopher)
Albert of Saxony was a German philosopher known for his contributions to logic and physics...
in the 14th century and was accepted in some form by most naturalist
Naturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
s by the 16th century.
Shen Kuo
Shen Kuo
Shen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...
(1031–1095) of the Song Dynasty
Song Dynasty
The Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...
used marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
fossils found in the Taihang Mountains
Taihang Mountains
The Taihang Mountains are a Chinese mountain range running down the eastern edge of the Loess Plateau in Henan, Shanxi and Hebei provinces. The range extends over 400 km from north to south and has an average elevation of 1,500 to 2,000 meters. The principal peak is Xiao Wutaishan...
to infer the existence of geological
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
processes such as geomorphology
Geomorphology
Geomorphology is the scientific study of landforms and the processes that shape them...
and the shifting of seashores over time. Using his observation of preserved petrified bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....
s found underground in Yan'an
Yan'an
Yan'an , is a prefecture-level city in the Shanbei region of Shaanxi province in China, administering several counties, including Zhidan County , which served as the Chinese communist capital before the city of Yan'an proper took that role....
, Shanbei
Shanbei
Shanbei specifies the northern portion of Shaanxi province, Northwest China, and is a natural as well as cultural area, forming part of the Loess Plateau...
region, Shaanxi
Shaanxi
' is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province...
province, he argued for a theory of gradual climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
, since Shaanxi was part of a dry climate zone that did not support a habitat for the growth of bamboos.
As a result of a new emphasis on observing, classifying, and cataloging nature, 16th century natural philosophers in Europe began to establish extensive collections of fossil objects (as well as collections of plant and animal specimens), which were often stored in specially built cabinets to help organize them. Conrad Gesner published a 1565 work on fossils that contained one of the first detailed descriptions of such a cabinet and collection. The collection belonged to a member of the extensive network of correspondents that Gesner drew on for his works. Such informal correspondence networks among natural philosophers and collectors became increasingly important during the course of the 16th century and were direct forerunners of the scientific societies that would begin to form in the 17th century. These cabinet collections and correspondence networks played an important role in the development of natural philosophy.
However, most 16th century Europeans did not recognize that fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s were the remains of living organisms. The etymology of the word fossil comes from the Latin for things having been dug up. As this indicates, the term was applied to wide variety of stone and stone-like objects without regard to whether they might have an organic origin. 16th century writers such as Gesner and Georg Agricola
Georg Agricola
Georgius Agricola was a German scholar and scientist. Known as "the father of mineralogy", he was born at Glauchau in Saxony. His real name was Georg Pawer; Agricola is the Latinised version of his name, Pawer meaning "farmer"...
were more interested in classifying such objects by their physical and mystical properties than they were in determining the objects' origins. In addition, the natural philosophy of the period encouraged alternative explanations for the origin of fossils. Both the Aristotelian
Aristotelianism
Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...
and Neoplatonic schools of philosophy provided support for the idea that stony objects might grow within the earth to resemble living things. Neoplatonic philosophy maintained that there could be affinities between living and non-living objects that could cause one to resemble the other. The Aristotelian school maintained that the seeds of living organisms could enter the ground and generate objects resembling those organisms.
17th century
Athanasius Kircher
Athanasius Kircher was a 17th century German Jesuit scholar who published around 40 works, most notably in the fields of oriental studies, geology, and medicine...
attributed giant bones to extinct races of giant humans in his Mundus subterraneus. In the same year Robert Hooke
Robert Hooke
Robert Hooke FRS was an English natural philosopher, architect and polymath.His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666, but...
published Micrographia
Micrographia
Micrographia is a historic book by Robert Hooke, detailing the then thirty year-old Hooke's observations through various lenses. Published in September 1665, the first major publication of the Royal Society, it was the first scientific best-seller, inspiring a wide public interest in the new...
, an illustrated collection of his observations with a microscope. One of these observations was entitled Of Petrify'd wood, and other Petrify'd bodies, which included a comparison between petrified and ordinary wood. He concluded that petrified wood was ordinary wood that had been soaked with "water impregnated with stony and earthy particles". He then suggested that several kinds of fossil sea shells were formed from ordinary shells by a similar process. He argued against the prevalent view that such objects were "Stones form'd by some extraordinary Plastick virtue latent in the Earth itself". Hooke believed that fossils provided evidence about the past history of life on Earth writing in 1668:
...if the finding of Coines, Medals, Urnes, and other Monuments of famous persons, or Towns, or Utensils, be admitted for unquestionable Proofs,that such Persons or things have, in former times had a being, certainly those Petrifactions may be allowed to be of equal Validity and Evidence, that there have formerly been such Vegetables or Animals... and are true universal Characters legible to all rational Men.
Hooke was prepared to accept the possibility that some such fossils represented species that had become extinct, possibly in past geological catastrophes.
Despite the considerable influence of Forerunner, naturalists such as Martin Lister
Martin Lister
Martin Lister FRS was an English naturalist and physician.-Life:Lister was born at Radcliffe, near Buckingham, the son of Sir Martin Lister MP for Brackley in the Long Parliament and his wife Susan Temple daughter of Sir Alexander Temple. Lister was connected to a number of well known individuals...
(1638–1712) and John Ray
John Ray
John Ray was an English naturalist, sometimes referred to as the father of English natural history. Until 1670, he wrote his name as John Wray. From then on, he used 'Ray', after "having ascertained that such had been the practice of his family before him".He published important works on botany,...
(1627–1705) continued to question the organic origin of some fossils. They were particularly concerned about objects such as fossil Ammonites, which Hooke claimed were organic in origin, that did not resemble any known living species. This raised the possibility of extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
, which they found difficult to accept for philosophical and theological reasons. In 1695 Ray wrote to the Welsh naturalist Edward Lluyd complaining of such views: "... there follows such a train of consequences, as seem to shock the Scripture-History of the novity of the World; at least they overthrow the opinion received, & not without good reason, among Divines and Philosophers, that since the first Creation there have have been no species of Animals or Vegetables lost, no new ones produced."
18th century
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....
in northern Europe, as evidence for the theory that the earth had started out much warmer than it currently was and had been gradually cooling.
In 1796 Georges Cuvier
Georges Cuvier
Georges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
presented a paper on living and fossil elephants comparing skeletal remains of Indian and African elephant
Elephant
Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...
s to fossils of mammoths and of an animal he would later name mastodon
Mastodon
Mastodons were large tusked mammal species of the extinct genus Mammut which inhabited Asia, Africa, Europe, North America and Central America from the Oligocene through Pleistocene, 33.9 mya to 11,000 years ago. The American mastodon is the most recent and best known species of the group...
utilizing comparative anatomy
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
. He established for the first time that Indian and African elephants were different species, and that mammoths differed from both and must be extinct. He further concluded that the mastodon was another extinct species that also differed from Indian or African elephants, more so than mammoths. Cuvier made another powerful demonstration of the power of comparative anatomy in paleontology when he presented a second paper in 1796 on a large fossil skeleton from Paraguay, which he named Megatherium
Megatherium
Megatherium was a genus of elephant-sized ground sloths endemic to Central America and South America that lived from the Pliocene through Pleistocene existing approximately...
and identified as a giant sloth by comparing its skull to those of two living species of tree sloth. Cuvier’s ground-breaking work in paleontology and comparative anatomy lead to the widespread acceptance of extinction. It also lead Cuvier to advocate the geological theory of catastrophism
Catastrophism
Catastrophism is the theory that the Earth has been affected in the past by sudden, short-lived, violent events, possibly worldwide in scope. The dominant paradigm of modern geology is uniformitarianism , in which slow incremental changes, such as erosion, create the Earth's appearance...
to explain the succession of organisms revealed by the fossil record. He also pointed out that since mammoths and wooly rhinoceros were not the same species as the elephants and rhinoceros currently living in the tropics, their fossils could not be used as evidence for a cooling earth.
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
, William Smith
William Smith (geologist)
William 'Strata' Smith was an English geologist, credited with creating the first nationwide geological map. He is known as the "Father of English Geology" for collating the geological history of England and Wales into a single record, although recognition was very slow in coming...
, a surveyor and mining engineer, made extensive use of fossils to help correlate rock strata in different locations. He created the first geological map of England during the late 1790s and early 19th century. He established the principle of faunal succession, the idea that each strata of sedimentary rock would contain particular types of fossils, and that these would succeed one another in a predictable way even in widely separated geologic formations. At the same time, Cuvier and Alexandre Brongniart
Alexandre Brongniart
Alexandre Brongniart was a French chemist, mineralogist, and zoologist, who collaborated with Georges Cuvier on a study of the geology of the region around Paris...
, an instructor at the Paris school of mine engineering, used similar methods in an influential study of the geology of the region around Paris.
The age of reptiles
Maastricht
Maastricht is situated on both sides of the Meuse river in the south-eastern part of the Netherlands, on the Belgian border and near the German border...
as a giant marine reptile that he named Mosasaurus
Mosasaurus
Mosasaurus is a genus of mosasaur, carnivorous, aquatic lizards, somewhat resembling flippered crocodiles, with elongated heavy jaws. The genus existed during the Maastrichtian age of the Cretaceous period , around 70-65 millions years ago in the area of modern Western Europe and North America...
. He also identified, from a drawing, another fossil found in Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
as a flying reptile and named it Pterodactylus
Pterodactylus
Pterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
. He speculated that an age of reptiles had preceded the first mammals. Cuvier's speculation would be supported by a series of finds that would be made in Great Britain over the course of the next two decades. Mary Anning
Mary Anning
Mary Anning was a British fossil collector, dealer and palaeontologist who became known around the world for a number of important finds she made in the Jurassic age marine fossil beds at Lyme Regis where she lived...
, a professional fossil collector since age eleven, collected the fossils of a number of marine reptiles from the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
marine strata at Lyme Regis
Lyme Regis
Lyme Regis is a coastal town in West Dorset, England, situated 25 miles west of Dorchester and east of Exeter. The town lies in Lyme Bay, on the English Channel coast at the Dorset-Devon border...
. These included the first ichthyosaur
Ichthyosaur
Ichthyosaurs were giant marine reptiles that resembled fish and dolphins...
skeleton to be recognized as such, which was collected in 1811, and the first two plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...
skeletons ever found in 1821 and 1823. Many of her discoveries would be described scientifically by the geologists William Conybeare, Henry De la Beche
Henry De la Beche
Sir Henry Thomas De la Beche FRS was an English geologist and palaeontologist who helped pioneer early geological survey methods.-Biography:...
, and William Buckland
William Buckland
The Very Rev. Dr William Buckland DD FRS was an English geologist, palaeontologist and Dean of Westminster, who wrote the first full account of a fossil dinosaur, which he named Megalosaurus...
. It was Anning who observed that stony objects known as "bezoar
Bezoar
A bezoar is a mass found trapped in the gastrointestinal system , though it can occur in other locations. A pseudobezoar is an indigestible object introduced intentionally into the digestive system....
stones" were often found in the abdominal region of ichthyosaur skeletons, and she noted that if such stones were broken open they often contained fossilized fish bones and scales as well as sometimes bones from small ichthyosaurs. This led Buckland to declare they were fossilized feces, which he named coprolite
Coprolite
A coprolite is fossilized animal dung. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour rather than morphology. The name is derived from the Greek words κοπρος / kopros meaning 'dung' and λιθος / lithos meaning 'stone'. They...
s, and he used them to better understand ancient food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
s.
In 1824, Buckland found and described a lower jaw from Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
deposits from Stonesfield
Stonesfield
Stonesfield is a village and civil parish about north of Witney in Oxfordshire.The village is on the crest of an escarpment. The parish extends mostly north and north-east of the village, in which directions the land rises gently and then descends to the Glyme at Glympton and Wootton about to the...
. He determined that the bone belonged to a carnivorous land-dwelling reptile he called Megalosaurus
Megalosaurus
Megalosaurus is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period of Europe...
. That same year Gideon Mantell
Gideon Mantell
Gideon Algernon Mantell MRCS FRS was an English obstetrician, geologist and palaeontologist...
realized that some large teeth he had found in 1822, in Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
rocks from Tilgate
Tilgate, Crawley
Tilgate is a neighbourhood within the town of Crawley in West Sussex, England. The area contains a mixture of privately developed housing, self build groups and ex-council housing...
, belonged to a giant herbivorous land-dwelling reptile. He called it Iguanodon
Iguanodon
Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...
, because the teeth resembled those of an iguana
Iguana
Iguana is a herbivorous genus of lizard native to tropical areas of Central America and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena...
. In 1832 Mantell would find, in Tilgate, a partial skeleton of an armoured reptile he would call Hylaeosaurus
Hylaeosaurus
Hylaeosaurus is the most obscure of the three animals used by Sir Richard Owen to first define the new group Dinosauria, in 1842. The original specimen, recovered by Gideon Mantell from the Tilgate Forest in the south of England in 1832, now resides in the Natural History Museum of London, where...
. In 1842 the English anatomist Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
would create a new order of reptiles, which he called Dinosauria, for Megalosaurus, Iguanodon, and Hylaeosaurus.
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
, but Buckland later realized it was a primitive placental mammal. Due to its small size and primitive nature, Buckland did not believe it invalidated the overall pattern of an "age of reptiles", when the largest and most conspicuous animals had been reptiles rather than mammals.
Paleobotany and the origin of the word paleontology
In 1828 Alexandre BrongniartAlexandre Brongniart
Alexandre Brongniart was a French chemist, mineralogist, and zoologist, who collaborated with Georges Cuvier on a study of the geology of the region around Paris...
's son, the botanist Adolphe Brongniart, published the introduction to a longer work on the history of fossil plants. Adolphe Brongniart concluded that the history of plants could roughly be divided into four parts. The first period was characterized by cryptogams
Cryptogams
The name cryptogams is used fairly widely as a phrase of convenience, although regarded as an obsolete taxonomic term. A cryptogam is a plant that reproduces by spores...
. The second period was characterized by the appearance of the conifers. The third period brought emergence of the cycads, and the fourth by the development of the flowering plants (such as the dicotyledons). The transitions between each of these periods was marked by sharp discontinuities in the fossil record, with more gradual changes within the periods. Brongniart's work is the foundation of paleobotany
Paleobotany
Paleobotany, also spelled as palaeobotany , is the branch of paleontology or paleobiology dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments , and both the evolutionary history of plants, with a...
and reinforced the theory that life on earth had a long and complex history, and different groups of plants and animals made their appearances in successive order. It also supported the idea that the Earth's climate had changed over time as Brogniart concluded that plant fossils showed that during the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
the climate of Northern Europe must have been tropical.
The increasing attention being paid to fossil plants in the first decades of the 19th century would trigger a significant change in the terminology for the study of past life. The editor of the influential French scientific journal, Journal de Phisique, a student of Cuvier's named Henri Marie Ducrotay de Blanville, coined the term "paleozoologie" in 1817 to refer to the work Cuvier and others were doing to reconstruct extinct animals from fossil bones. However, Blanville began looking for a term that could refer to the study of both fossil animal and plant remains. After trying some unsuccessful alternatives, he hit on "paleontologie" in 1822. Blanville's term for the study of the living organisms of the past quickly became popular and was anglicized into "paleontology".
Catastrophism, uniformitarianism and the fossil record
In Cuvier's landmark 1796 paper on living and fossil elephants, he referred to a single catastrophe that destroyed life to be replaced by the current forms. As a result of his studies of extinct mammals, he realized that animals such as PalaeotheriumPalaeotherium
Palaeotherium is an extinct genus of primitive perissodactyl ungulate. George Cuvier originally described them as being a kind of tapir, and as such, Palaeotherium is popularly reconstructed as a tapir-like animal...
had lived before the time of the mammoths, which lead him to write in terms of multiple geological catastrophes that had wiped out a series of successive faunas. By 1830, a scientific consensus
Scientific community
The scientific community consists of the total body of scientists, its relationships and interactions. It is normally divided into "sub-communities" each working on a particular field within science. Objectivity is expected to be achieved by the scientific method...
had formed around his ideas as a result of paleobotany and the dinosaur and marine reptile discoveries in Britain. In Great Britain, where natural theology
Natural theology
Natural theology is a branch of theology based on reason and ordinary experience. Thus it is distinguished from revealed theology which is based on scripture and religious experiences of various kinds; and also from transcendental theology, theology from a priori reasoning.Marcus Terentius Varro ...
was very influential in the early 19th century, a group of geologists that included Buckland, and Robert Jameson
Robert Jameson
thumb|Robert JamesonProfessor Robert Jameson, FRS FRSE was a Scottish naturalist and mineralogist.As Regius Professor at the University of Edinburgh for fifty years, Jameson is notable for his advanced scholarship in natural history, his superb museum collection, and for his tuition of Charles...
insisted on explicitly linking the most recent of Cuvier's catastrophes to the biblical flood
Flood geology
Flood geology is the interpretation of the geological history of the Earth in terms of the global flood described in Genesis 6–9. Similar views played a part in the early development of the science of geology, even after the Biblical chronology had been rejected by geologists in favour of an...
. Catastrophism had a religious overtone in Britain that was absent elsewhere.
Partly in response to what he saw as unsound and unscientific speculations by William Buckland
William Buckland
The Very Rev. Dr William Buckland DD FRS was an English geologist, palaeontologist and Dean of Westminster, who wrote the first full account of a fossil dinosaur, which he named Megalosaurus...
and other practitioners of flood geology, Charles Lyell
Charles Lyell
Sir Charles Lyell, 1st Baronet, Kt FRS was a British lawyer and the foremost geologist of his day. He is best known as the author of Principles of Geology, which popularised James Hutton's concepts of uniformitarianism – the idea that the earth was shaped by slow-moving forces still in operation...
advocated the geological theory of uniformitarianism
Uniformitarianism (science)
In the philosophy of naturalism, the uniformitarianism assumption is that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe. It has included the gradualistic concept that "the present is the...
in his influential work Principles of Geology
Principles of Geology
Principles of Geology, being an attempt to explain the former changes of the Earth's surface, by reference to causes now in operation, is a book by the Scottish geologist Charles Lyell....
. Lyell amassed evidence, both from his own field research and the work of others, that most geological features could be explained by the slow action of present day forces, such as vulcanism, earthquakes, erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
, and sedimentation
Sedimentation
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...
rather than past catastrophic events. Lyell also claimed that the apparent evidence for catastrophic changes in the fossil record, and even the appearance of directional succession in the history of life, were illusions caused by imperfections in that record. For instance he argued that the absence of birds and mammals from the earliest fossil strata was merely an imperfection in the fossil record attributable to the fact that marine organisms were more easily fossilized. Also Lyell pointed to the Stonesfield mammal as evidence that mammals had not necessarily been preceded by reptiles, and to the fact that certain Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
strata showed a mixture of extinct and still surviving species, which he said showed that extinction occurred piecemeal rather than as a result of catastrophic events. Lyell was successful in convincing geologists of the idea that the geological features of the earth were largely due to the action of the same geologic forces that could be observed in the present day, acting over an extended period of time. He was not successful in gaining support for his view of the fossil record, which he believed did not support a theory of directional succession.
Transmutation of species and the fossil record
Jean Baptiste Lamarck used fossils in his arguments for his theory of the transmutation of species in the early 19th century. Fossil finds, and the emerging evidence that life had changed over time, fueled speculation on this topic during the next few decades. Robert Chambers used fossil evidence in his 1844 popular science book Vestiges of the Natural History of CreationVestiges of the Natural History of Creation
Vestiges of the Natural History of Creation is a unique work of speculative natural history published anonymously in England in 1844. It brought together various ideas of stellar evolution with the progressive transmutation of species in an accessible narrative which tied together numerous...
, which advocated an evolutionary origin for the cosmos as well as for life on earth. Like Lamarck's theory it maintained that life had progressed from the simple to the complex. These early evolutionary ideas were widely discussed in scientific circles but were not accepted into the scientific mainstream. Many of the critics of transmutational ideas used fossil evidence in their arguments. In the same paper that coined the term dinosaur Richard Owen pointed out that dinosaurs were at least as sophisticated and complex as modern reptiles, which he claimed contradicted transmutational theories. Hugh Miller
Hugh Miller
Hugh Miller was a self-taught Scottish geologist and writer, folklorist and an evangelical Christian.- Life and work :Born in Cromarty, he was educated in a parish school where he reportedly showed a love of reading. At 17 he was apprenticed to a stonemason, and his work in quarries, together with...
would make a similar argument, pointing out that the fossil fish found in the Old Red Sandstone formation were fully as complex as any later fish, and not the primitive forms alleged by Vestiges. While these early evolutionary theories failed to become accepted as mainstream science, the debates over them would help pave the way for the acceptance of Darwin's theory of evolution by natural selection a few years later.
Geological time scale and the history of life
Geologists such as Adam SedgwickAdam Sedgwick
Adam Sedgwick was one of the founders of modern geology. He proposed the Devonian period of the geological timescale...
, and Roderick Murchison
Roderick Murchison
Sir Roderick Impey Murchison, 1st Baronet KCB DCL FRS FRSE FLS PRGS PBA MRIA was a Scottish geologist who first described and investigated the Silurian system.-Early life and work:...
continued, in the course of disputes such as The Great Devonian Controversy
The Great Devonian Controversy
The Great Devonian Controversy began in 1834 when Roderick Murchison disagreed with Henry De La Beche as to the dating of certain petrified plants found in coals in the Greywacke strata in North Devon, England...
, to make advances in stratigraphy. They described new geological epochs such as the Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
, the Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
, the Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
, and the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
. Increasingly, such progress in stratigraphy depended on the opinions of experts with specialized knowledge of particular types of fossils such as William Lonsdale
William Lonsdale
William Lonsdale , English geologist and palaeontologist, won the Wollaston medal in 1846 for his research on the various kinds of fossil corals.-Biography:...
(fossil corals), and John Lindley
John Lindley
John Lindley FRS was an English botanist, gardener and orchidologist.-Early years:Born in Catton, near Norwich, England, John Lindley was one of four children of George and Mary Lindley. George Lindley was a nurseryman and pomologist and ran a commercial nursery garden...
(fossil plants) who both played a role in the Devonian controversy and its resolution. By the early 1840s much of the geologic time scale had been developed. In 1841, John Phillips
John Phillips (geologist)
John Phillips FRS was an English geologist.- Life and work :Philips was born at Marden in Wiltshire...
formally divided the geologic column into three major eras, the Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
, Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
, and Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
, based on sharp breaks in the fossil record. He identified the three periods of the Mesozoic era and all the periods of the Paleozoic era except the Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
. His definition of the geological time scale is still used today. It remained a relative time scale with no method of assigning any of the periods' absolute dates. It was understood that not only had there been an "age of reptiles" preceding the current "age of mammals", but there had a time (during the Cambrian and the Silurian) when life had been restricted to the sea, and a time (prior to the Devonian) when invertebrates had been the largest and most complex forms of animal life.
Expansion and professionalization of geology and paleontology
This rapid progress in geology and paleontology during the 1830s and 1840s was aided by a growing international network of geologists and fossil specialists whose work was organized and reviewed by an increasing number of geological societies. Many of these geologists and paleontologists were now paid professionals working for universities, museums and government geological surveys. The relatively high level of public support for the earth sciences was due to their cultural impact, and their proven economic value in helping to exploit mineral resources such as coal.Another important factor was the development in the late 18th and early 19th centuries of museums with large natural history collections. These museums received specimens from collectors around the world and served as centers for the study of comparative anatomy and morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
. These disciplines played key roles in the development of a more technically sophisticated form of natural history. One of the first and most important examples was the Museum of Natural History in Paris, which was at the center of many of the developments in natural history during the first decades of the 19th century. It was founded in 1793 by an act of the French National Assembly, and was based on an extensive royal collection plus the private collections of aristocrats confiscated during the French revolution
French Revolution
The French Revolution , sometimes distinguished as the 'Great French Revolution' , was a period of radical social and political upheaval in France and Europe. The absolute monarchy that had ruled France for centuries collapsed in three years...
, and expanded by material seized during French military conquests. The Paris museum was the professional base for Cuvier, and his professional rival Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire was a French naturalist who established the principle of "unity of composition". He was a colleague of Jean-Baptiste Lamarck and expanded and defended Lamarck's evolutionary theories...
. The English anatomists Robert Grant
Robert Edmond Grant
Robert Edmond Grant MD FRCPEd FRS was born in Edinburgh and educated at Edinburgh University as a physician. He became one of the foremost biologists of the early 19th century at Edinburgh and subsequently the first Professor of Comparative Anatomy at University College London...
and Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
both spent time studying there. Owen would go on to become the leading British morphologist while working at the museum of the Royal College of Surgeons
Royal College of Surgeons of England
The Royal College of Surgeons of England is an independent professional body and registered charity committed to promoting and advancing the highest standards of surgical care for patients, regulating surgery, including dentistry, in England and Wales...
.
Evolution
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
's publication of the On the Origin of Species in 1859 was a watershed event in all the life sciences, especially paleontology. Fossils had played a role in the development of Darwin's theory. In particular he had been impressed by fossils he had collected in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
during the voyage of the Beagle
Second voyage of HMS Beagle
The second voyage of HMS Beagle, from 27 December 1831 to 2 October 1836, was the second survey expedition of HMS Beagle, under captain Robert FitzRoy who had taken over command of the ship on its first voyage after her previous captain committed suicide...
of giant armadillo
Glyptodon
Glyptodon was a large, armored mammal of the family Glyptodontidae, a relative of armadillos that lived during the Pleistocene Epoch. It was roughly the same size and weight as a Volkswagen Beetle, though flatter in shape...
s, giant sloths, and what at the time he thought were giant llama
Macrauchenia
Macrauchenia was a long-necked and long-limbed, three-toed South American ungulate mammal, typifying the order Litopterna. The oldest fossils date back to around 7 million years ago, and M...
s that seemed to be related to species still living on the continent in modern times. The scientific debate that started immediately after the publication of Origin led to a concerted effort to look for transitional fossils and other evidence of evolution in the fossil record. There were two areas where early success attracted considerable public attention, the transition between reptiles and birds, and the evolution of the modern single-toed horse. In 1861 the first specimen of Archaeopteryx
Archaeopteryx
Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...
, an animal with both teeth and feathers and a mix of other reptilian and avian features, was discovered in a limestone quarry in Bavaria and described by Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
. Another would be found in the late 1870s and put on display at a Museum in Berlin in 1881. Other primitive toothed birds were found by Othniel Marsh in Kansas in 1872. Marsh also discovered fossils of several primitive horses in the Western United States that helped trace the evolution of the horse
Evolution of the horse
The evolution of the horse pertains to the phylogenetic ancestry of the modern horse from the small dog-sized, forest-dwelling Hyracotherium over geologic time scales...
from the small 5-toed Hyracotherium
Hyracotherium
Hyracotherium , also known as Eohippus or the dawn horse, is an extinct genus of very small perissodactyl ungulates that lived in the woodlands of the northern hemisphere, with species ranging throughout Asia, Europe, and North America during the early Tertiary Period and the early to mid Eocene...
of the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
to the much larger single-toed modern horses of the genus Equus. Thomas Huxley
Thomas Huxley
Thomas Henry Huxley PC FRS was an English biologist, known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution....
would make extensive use of both the horse and bird fossils in his advocacy of evolution. Acceptance of evolution occurred rapidly in scientific circles, but acceptance of Darwin's proposed mechanism of natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
as the driving force behind it was much less universal. In particular some paleontologists such as Edward Drinker Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
and Henry Fairfield Osborn
Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. ForMemRS was an American geologist, paleontologist, and eugenicist.-Early life and career:...
preferred alternatives such as neo-Lamarckism
Lamarckism
Lamarckism is the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring . It is named after the French biologist Jean-Baptiste Lamarck , who incorporated the action of soft inheritance into his evolutionary theories...
, the inheritance of characteristics acquired during life, and orthogenesis
Orthogenesis
Orthogenesis, orthogenetic evolution, progressive evolution or autogenesis, is the hypothesis that life has an innate tendency to evolve in a unilinear fashion due to some internal or external "driving force". The hypothesis is based on essentialism and cosmic teleology and proposes an intrinsic...
, an innate drive to change in a particular direction, to explain what they perceived as linear trends in evolution.
Java Man
Java Man is the name given to fossils discovered in 1891 at Trinil - Ngawi Regency on the banks of the Solo River in East Java, Indonesia, one of the first known specimens of Homo erectus...
, the first fossil evidence of a species that seemed clearly intermediate between humans and apes, in 1891.
Developments in North America
A major development in the second half of the 19th century was a rapid expansion of paleontology in North America. In 1858 Joseph LeidyJoseph Leidy
Joseph Leidy was an American paleontologist.Leidy was professor of anatomy at the University of Pennsylvania, and later was a professor of natural history at Swarthmore College. His book Extinct Fauna of Dakota and Nebraska contained many species not previously described and many previously...
described a Hadrosaurus
Hadrosaurus
Hadrosaurus is a valid genus of hadrosaurid dinosaur. In 1858, a skeleton of a dinosaur from this genus was the first dinosaur skeleton known from more than isolated teeth to be found in North America. In 1868, it became the first ever mounted dinosaur skeleton...
skeleton, which was the first North American dinosaur to be described from good remains. However, it was the massive westward expansion of railroads, military bases, and settlements into Kansas and other parts of the Western United States following the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...
that really fueled the expansion of fossil collection. The result was an increased understanding of the natural history of North America, including the discovery of the Western Interior Sea that had covered Kansas and much of the rest of the Midwestern United States during parts of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, the discovery several important fossils of primitive birds and horses, and the discovery of a number of new dinosaur genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
including Allosaurus
Allosaurus
Allosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period . The name Allosaurus means "different lizard". It is derived from the Greek /allos and /sauros...
, Stegosaurus
Stegosaurus
Stegosaurus is a genus of armored stegosaurid dinosaur. They lived during the Late Jurassic period , some 155 to 150 million years ago in what is now western North America. In 2006, a specimen of Stegosaurus was announced from Portugal, showing that they were present in Europe as well...
, and Triceratops
Triceratops
Triceratops is a genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago in what is now North America. It was one of the last dinosaur genera to appear before the great Cretaceous–Paleogene...
. Much of this activity was part of a fierce personal and professional rivalry between two men, Othniel Marsh, and Edward Cope, which has become known as the Bone Wars
Bone Wars
The Bone Wars, also known as the "Great Dinosaur Rush", refers to a period of intense fossil speculation and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope and Othniel Charles Marsh...
.
Developments in geology
Two 20th century developments in geology had a big effect on paleontology. The first was the development of radiometric datingRadiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
, which allowed absolute dates to be assigned to the geologic timescale. The second was the theory of plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
, which helped make sense of the geographical distribution of ancient life.
Geographical expansion of paleontology
During the 20th century paleontological exploration intensified everywhere and ceased to be a largely European and North American activity. In the 135 years between Buckland's first discovery and 1969 a total of 170 dinosaur genera were known. In the 25 years after 1969 that number increased to 315. Much of this increase was due to the examination of new rock exposures, particularly in previously little-explored areas in South AmericaSouth America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Near the end of the century the opening of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
to systematic exploration for fossils has yielded a wealth of material on dinosaurs and the origin of birds and mammals.
Mass extinctions
The 20th century saw a major renewal of interest in mass extinction events and their effect on the course of the history of life. This was particularly true after 1980 when Luis and Walter Alvarez put forward the Alvarez hypothesisAlvarez hypothesis
The Alvarez hypothesis claims that the mass extinction of the dinosaurs and many other living things was caused by the impact of a large asteroid on the Earth sixty-five million years ago, called the Cretaceous-Tertiary extinction event. Evidence indicates that the asteroid fell in the Yucatán...
claiming that an impact event
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
caused the Cretaceous–Tertiary extinction event, which killed off the non-avian dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s along with many other living things. Also in the early 1980s Jack Sepkoski
Jack Sepkoski
J. John Sepkoski Jr., , was a University of Chicago paleontologist. Sepkoski studied the fossil record and the diversity of life on Earth. Sepkoski and David Raup contributed to the knowledge of extinction events...
and David M. Raup
David M. Raup
David M. Raup is a University of Chicago paleontologist. Raup studied the fossil record and the diversity of life on Earth. Raup contributed to the knowledge of extinction events along with his colleague Jack Sepkoski...
published papers with statistical analysis of the fossil record of marine invertebrates that revealed a pattern (possibly cyclical) of repeated mass extinctions with significant implications for the evolutionary history of life.
Evolutionary paths and theory
Taung Child
The Taung Child — or Taung Baby — is the fossilized skull of a young Australopithecus africanus individual. It was discovered in 1924 by quarrymen working for the Northern Lime Company in Taung, South Africa...
in 1924) and elsewhere have helped illuminate the course of human evolution
Human evolution
Human evolution refers to the evolutionary history of the genus Homo, including the emergence of Homo sapiens as a distinct species and as a unique category of hominids and mammals...
. Increasingly, at the end of the century, the results of paleontology and molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
were being brought together to reveal detailed phylogenetic tree
Phylogenetic tree
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...
s.
The results of paleontology have also contributed to the development of evolutionary theory. In 1944 George Gaylord Simpson
George Gaylord Simpson
George Gaylord Simpson was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the modern evolutionary synthesis, contributing Tempo and mode in evolution , The meaning of evolution and The major features of...
published Tempo and Mode in Evolution, which used quantitative analysis to show that the fossil record was consistent with the branching, non-directional, patterns predicted by the advocates of evolution driven by natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
and genetic drift
Genetic drift
Genetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...
rather than the linear trends predicted by earlier advocates of neo-Lamarckism
Lamarckism
Lamarckism is the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring . It is named after the French biologist Jean-Baptiste Lamarck , who incorporated the action of soft inheritance into his evolutionary theories...
and orthogenesis
Orthogenesis
Orthogenesis, orthogenetic evolution, progressive evolution or autogenesis, is the hypothesis that life has an innate tendency to evolve in a unilinear fashion due to some internal or external "driving force". The hypothesis is based on essentialism and cosmic teleology and proposes an intrinsic...
. This integrated paleontology into the modern evolutionary synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
. In 1972 Niles Eldredge
Niles Eldredge
Niles Eldredge is an American paleontologist, who, along with Stephen Jay Gould, proposed the theory of punctuated equilibrium in 1972.-Education:...
and Stephen Jay Gould
Stephen Jay Gould
Stephen Jay Gould was an American paleontologist, evolutionary biologist, and historian of science. He was also one of the most influential and widely read writers of popular science of his generation....
used fossil evidence to advocate the theory of punctuated equilibrium
Punctuated equilibrium
Punctuated equilibrium is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis...
, which maintains that evolution is characterized by long periods of relative stasis and much shorter periods of relatively rapid change.
Cambrian explosion
Cambrian explosion
The Cambrian explosion or Cambrian radiation was the relatively rapid appearance, around , of most major phyla, as demonstrated in the fossil record, accompanied by major diversification of other organisms, including animals, phytoplankton, and calcimicrobes...
during which many of the various phyla
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
of animals with their distinctive body plans first appear. The well-known Burgess Shale
Burgess Shale
The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...
Cambrian fossil site was found in 1909 by Charles Doolittle Walcott
Charles Doolittle Walcott
Charles Doolittle Walcott was an American invertebrate paleontologist. He became known for his discovery in 1909 of well-preserved fossils in the Burgess Shale of British Columbia, Canada.-Early life:...
, and another important site in Chengjiang
Maotianshan shales
The Maotianshan Shales are a series of lower Cambrian deposits in the Chiungchussu formation, famous for their Konservat Lagerstätten, or high number of fossils preserved in place...
China was found in 1912. However, new analysis in the 1980s by Harry B. Whittington
Harry B. Whittington
Harry Blackmore Whittington FRS was a British paleontologist based at the Department of Earth Sciences, Cambridge, and was affiliated to Sidney Sussex College. He attended Handsworth Grammar School in Birmingham, followed by a degree and Ph.D in geology from the University of Birmingham...
, Derek Briggs
Derek Briggs
Derek Ernest Gilmor Briggs is an Irish paleontologist and taphonomist based at Yale University. Briggs is one of three paleontologists who were key in the reinterpretation of the fossils of the Burgess Shale.-Professional achievements:...
, Simon Conway Morris
Simon Conway Morris
Simon Conway Morris FRS is an English paleontologist made known by his detailed and careful study of the Burgess Shale fossils, an exploit celebrated in Wonderful Life by Stephen Jay Gould...
and others sparked a renewed interest and a burst of activity including discovery of an important new fossil site, Sirius Passet
Sirius Passet
Sirius Passet is a Cambrian Lagerstätte in Greenland. The Sirius Passet Lagerstätte was named after the Sirius sledge patrol that operates in North Greenland. It comprises six localities located on the eastern shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A....
, in Greenland, and the publication of a popular and controversial book, Wonderful Life
Wonderful Life (book)
Wonderful Life: The Burgess Shale and the Nature of History is a book on the evolution of Cambrian fauna by Harvard paleontologist Stephen Jay Gould...
by Stephen Jay Gould
Stephen Jay Gould
Stephen Jay Gould was an American paleontologist, evolutionary biologist, and historian of science. He was also one of the most influential and widely read writers of popular science of his generation....
in 1989.
Pre-Cambrian fossils
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
wrote The Origin of Species he acknowledged that the lack of any fossil evidence of life prior to the relatively complex animals of the Cambrian was a potential argument against the theory of evolution, but expressed the hope that such fossils would be found in the future. In the 1860s there were claims of the discovery of pre-Cambrian fossils, but these would later be shown not to have an organic origin. In the late 19th century Charles Doolittle Walcott would discover stromatolites and other fossil evidence of pre-Cambrian life, but at the time the organic origin of those fossils was also disputed. This would start to change in the 1950s with the discovery of more stromatolites along with microfossils of the bacteria that built them, and the publication of a series of papers by the Soviet scientist Boris Vasil'evich Timofeev announcing the discovery of microscopic fossil spores in pre-Cambrian sediments. A key breakthrough would come when Martin Glaessner
Martin Glaessner
Martin Fritz Glaessner AM was a geologist and palaeontologist. Born and educated in Austro-Hungarian Empire, he spent the majority of his life in working for oil companies in Russia, and studying the geology of the South Pacific in Australia...
would show that fossils of soft bodied animals discovered by Reginald Sprigg during the late 1940s in the Ediacaran hills of Australia were in fact pre-Cambrian not early Cambrian as Sprigg had originally believed, making the Ediacaran biota the oldest animals known. By the end of the 20th century paleobiology
Paleobiology
Paleobiology is a growing and comparatively new discipline which combines the methods and findings of the natural science biology with the methods and findings of the earth science paleontology...
had established that the history of life extended back at least 3.5 billion years.
See also
- List of fossil sites (with link directory)
- List of years in paleontology
- History of biologyHistory of biologyThe history of biology traces the study of the living world from ancient to modern times. Although the concept of biology as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to ayurveda, ancient Egyptian...
- History of evolutionary thoughtHistory of evolutionary thoughtEvolutionary thought, the conception that species change over time, has roots in antiquity, in the ideas of the ancient Greeks, Romans, and Chinese as well as in medieval Islamic science...
- History of geologyHistory of geologyThe history of geology is concerned with the development of the natural science of geology. Geology is the scientific study of the origin, history, and structure of the Earth. Throughout the ages geology provides essential theories and data that shape how society conceptualizes the...
- History of scienceHistory of scienceThe history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
- Taxonomy of commonly fossilised invertebratesTaxonomy of commonly fossilised invertebratesAlthough the phylogenetic classification of sub-vertebrate animals remains a work-in-progress, the following taxonomy attempts to be useful by combining both traditional and new paleozoological terminology....
- Treatise on Invertebrate PaleontologyTreatise on Invertebrate PaleontologyThe Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and...