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Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of
fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
. Paleontologists use fossils as a means to classify
organisms An organism is any living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have been pr ...
, measure
geologic time The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronolo ...
, and assess the interactions between
prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins  million years ago and the beginning of recorded history with the invention of writing systems. The use o ...
organisms and their
natural environment The natural environment or natural world encompasses all life, biotic and abiotic component, abiotic things occurring nature, naturally, meaning in this case not artificiality, artificial. The term is most often applied to Earth or some parts ...
. While paleontological observations are known from at least the
6th century BC The 6th century BC started on the first day of 600 BC and ended on the last day of 501 BC. In Western Asia, the first half of this century was dominated by the Neo-Babylonian Empire, which had risen to power late in the previous century after ...
, the foundation of paleontology as a science dates back to the work of
Georges Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...
in
1796 Events January–March * January 16 – The first Dutch (and general) elections are held for the National Assembly of the Batavian Republic. (The next Dutch general elections are held in 1888.) * February 1 – The capital of Upper Can ...
. Cuvier demonstrated evidence for the concept of
extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
and how life of the past was not necessarily the same as that of the present. The field developed rapidly over the course of the following decades, and the French word ''paléontologie'' was introduced for the study in
1822 Events January–March * January 1 – The Greek Constitution of 1822 is adopted by the First National Assembly at Epidaurus. * January 3 – The famous French explorer, Aimé Bonpland, is imprisoned in Paraguay on charges of espionage. ...
, which was derived from the
Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
word for "ancient" and words describing relatedness and a field of study. Further advances in the field accompanied the work of
Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...
who popularized the concept of
evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
. Together, evolution and extinction can be understood as complementary processes which shaped the
history of life The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as ''Ga'', for '' gigaannum'') and ...
. Paleontology overlaps the most with the fields of
geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
and
biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...
. It draws on technology and analysis of a wide range of sciences to apply them to the study of life and environments of the past, particularly for the subdisciplines of
paleobiology Paleobiology (or palaeobiology) is an interdisciplinary field that combines the methods and findings found in both the earth sciences and the life sciences. An investigator in this field is known as a paleobiologist. Paleobiology is closely ...
and
paleoecology Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...
that are analogous to biology and
ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...
. Paleontology also contributes to other sciences, being utilized for
biostratigraphy Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...
to reconstruct the
geologic time scale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochro ...
of Earth, or in studies on extinction to establish both external and internal factors that can lead to the disappearance of a
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
. Much of the history of life is now better understood because of advances in paleontology and the increase of
interdisciplinary studies Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several fields such as sociology, anthropology, psychology, economi ...
. Several improvements in understanding have occurred from the introduction of theoretical analysis to paleontology in the 1950s and 1960s that led to the rise of more focused fields of paleontology that assess the changing
geography Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...
and
climate Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...
of Earth, the
phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
relationships between different species, and the analysis of how
fossilization A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
occurs and what biases can impact the quality of the
fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
. Paleontology is also one of the most high profile of the sciences, comparable to
astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the ...
and
global health Global health is the health of populations in a worldwide context; it has been defined as "the area of study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide". Problems th ...
in the amount of attention in
mass media Mass media include the diverse arrays of media that reach a large audience via mass communication. Broadcast media transmit information electronically via media such as films, radio, recorded music, or television. Digital media comprises b ...
. Public attention to paleontology can be traced back to the
mythologies Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...
of
indigenous peoples There is no generally accepted definition of Indigenous peoples, although in the 21st century the focus has been on self-identification, cultural difference from other groups in a state, a special relationship with their traditional territ ...
of many continents and the interpretation of discovered fossils as the bones of
dragon A dragon is a Magic (supernatural), magical legendary creature that appears in the folklore of multiple cultures worldwide. Beliefs about dragons vary considerably through regions, but European dragon, dragons in Western cultures since the Hi ...
s or
giant In folklore, giants (from Ancient Greek: ''wiktionary:gigas, gigas'', cognate wiktionary:giga-, giga-) are beings of humanoid appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''gia ...
s. Prehistoric life is used as the inspiration for
toys A toy or plaything is an object that is used primarily to provide entertainment. Simple examples include toy blocks, board games, and dolls. Toys are often designed for use by children, although many are designed specifically for adults and ...
, television and
film A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, sinc ...
,
computer games A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...
, and
tourism Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...
, with the budgets for these public projects often exceeding the funding within the field of paleontology itself. This has led to exploitation and
imperialism Imperialism is the maintaining and extending of Power (international relations), power over foreign nations, particularly through expansionism, employing both hard power (military and economic power) and soft power (diplomatic power and cultura ...
of fossils collected for institutions in Europe and North America, and also appeals to the public for sponsorships to the benefit of some areas of paleontology at the detriment of others. Since the novel and film ''
Jurassic Park ''Jurassic Park'', later referred to as ''Jurassic World'', is an American science fiction media franchise created by Michael Crichton, centered on a disastrous attempt to create a theme park of De-extinction#Cloning, cloned dinosaurs. It bega ...
'', the focus of paleontology in the public has been on
dinosaurs Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
, making them some of the most familiar organisms from the deep past.


Concept

Paleontology (also spelled palaeontology) is the study of life of the past, characterized but not defined by the study and interpretation of
fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
. It overlaps with the fields of
geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
and
biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...
especially, but also with
ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...
,
chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
,
physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...
and
mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...
. Paleontology consists of both conceptual theorizing and focused scientific study. Traditionally, the sub-field of
invertebrate paleontology Invertebrate paleontology (also spelled invertebrate palaeontology) is sometimes described as invertebrate paleozoology or invertebrate paleobiology. Whether it is considered to be a subfield of paleontology, paleozoology, or paleobiology, this d ...
has been closely tied to the study of geology,
biostratigraphy Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...
, and historical geology, which have both commercial and academic drivers, whereas
vertebrate paleontology Vertebrate paleontology is the subfield of paleontology that seeks to discover, through the study of fossilized remains, the behavior, reproduction and appearance of extinct vertebrates (animals with vertebrae and their descendants). It also t ...
has been more closely tied to biology with limited commercial applications. Both areas of study have broadened over time as a result of developing technology, but the "classical" requirements of
fieldwork Field research, field studies, or fieldwork is the collection of raw data outside a laboratory, library, or workplace setting. The approaches and methods used in field research vary across disciplines. For example, biologists who conduct f ...
,
laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratories are found in a variety of settings such as schools ...
preparation, and study of
comparative anatomy Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species). The science began in the classical era, continuing in t ...
remain core components of most sub-fields of paleontology. Paleontological study provides a direct source of information on the
anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...
,
physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...
, ecology, and
chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the deter ...
of life on Earth, and the fossil record can be used to test hypotheses relevant to a range of scientific disciplines including other
earth science Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...
s and
life science Life, also known as biota, refers to matter that has biological processes, such as signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, organisation, metabolism, growth, adaptation, respon ...
s. The word paleontology or palaeontology is a compound word formed from the roots "paleo-", "onto-" and "-logy", equivalent to the French word paléontologie or the German word Paläontologie. The spelling paleontology is primarily used in North America, while the spelling palaeontology is preferred in the United Kingdom and was historic spelled as palæontology. Multiple different pronunciations can be found, including (), (), and (). The root word "paleo-" is from the
classical Latin Classical Latin is the form of Literary Latin recognized as a Literary language, literary standard language, standard by writers of the late Roman Republic and early Roman Empire. It formed parallel to Vulgar Latin around 75 BC out of Old Latin ...
or
scientific Latin Contemporary Latin is the form of the Literary Latin used since the end of the 19th century. Various kinds of contemporary Latin can be distinguished, including the use of Neo-Latin words in taxonomy and in science generally, and the fuller ec ...
''palaeo-'' and its predecessor
Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
παλαιο- meaning "ancient" or "old", the root noun "onto-" is from the Ancient Greek ὀντ- meaning a sense of relatedness, and the root word "-logy" is from the French ''‑logie'' which derives from the classical Latin ''‑logia'' and the Ancient Greek ''‑λογία'' and in context means a field of study.


Foundation

Paleontology includes the study of extinct animals and plants, including both direct observations about their remains and inferences about their behavior and how they interacted with their environment. From the recognition that fossils represented the remains of
extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
organisms, paleontology became the zoology, botany, and biology of extinct organisms and therefore an important source for comparative anatomy. It was not always understood that paleontology is an evolutionary science, but over time, instances of
evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
were recognized in the fossil record, and the two concepts have been closely linked ever since. The long span of geological time preserved in the fossil record allows very slow evolutionary changes to be observed, and the discovery of extinct organisms has allowed scientists to fill in gaps in the tree of life than cannot be understood through the study of
extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...
organisms. The incorporation of a wider range of life sciences has allowed sub-disciplines like
paleobiology Paleobiology (or palaeobiology) is an interdisciplinary field that combines the methods and findings found in both the earth sciences and the life sciences. An investigator in this field is known as a paleobiologist. Paleobiology is closely ...
and others to emerge.


Fossils

Prior to the
19th century The 19th century began on 1 January 1801 (represented by the Roman numerals MDCCCI), and ended on 31 December 1900 (MCM). It was the 9th century of the 2nd millennium. It was characterized by vast social upheaval. Slavery was Abolitionism, ...
, the word "fossil" was used as a descriptive noun to characterize anything that had been dug out of the ground, including bones, stones, and gems. Early descriptions of what we now understand to be fossils described their appearances alongside and in the context of other
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...
s,
crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
s, and rocks. These early publications varied in contents of "fossils" across a wide spectrum of inorganic to organic appearances, including true fossils of differing preservation qualities, inorganic concretions, and structures with a resemblance to organisms. Over time the criteria for separating organic fossils from potentially organic or clearly inorganic materials brought about a change in the
etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...
of the word "fossil" itself, so accounts before the 19th century may not reflect the same use of the word fossil as modern paleontology. Both inorganic and organic fossils were illustrated in numerous books on the topic throughout the 16th century, with some attributing them to the work of
God In monotheistic belief systems, God is usually viewed as the supreme being, creator, and principal object of faith. In polytheistic belief systems, a god is "a spirit or being believed to have created, or for controlling some part of the un ...
and other suggesting applications in construction or medicine. Fossils were not believed to have been organic, but instead to have exhibited the same kind of "growth" as crystals. Support for a possibly organic nature of fossils began in the
17th century The 17th century lasted from January 1, 1601 (represented by the Roman numerals MDCI), to December 31, 1700 (MDCC). It falls into the early modern period of Europe and in that continent (whose impact on the world was increasing) was characterized ...
, though it remained contentious as different quarries or
strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...
yielded different fossils, which the scientists of the time did not have the context to explain. The fact that most fossils came from organisms that had never been observed alive anywhere in the world seemed to imply that these organisms were extinct, which was contrary to the belief of a perfect divine creation. Another compounding factor was that fossils of apparently marine animals were found in parts of the world that were well above
sea-level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...
. Some suggested that these fossils had accumulated in horizontal layers under the sea and that subsequent tectonic activity had displaced them from their original positions. As these observations were made over time, it was eventually understood that fossils could be used to make inferences about the history of life from their presence or absence in particular areas over time. The fossil record is the main tool used by scientists to study the history of life and assess the diversification of life over time. Very little is known about the origins of life and the oldest life forms, and this is likely a result of the poor quality of fossil preservation in older rocks. Older rocks preserve less information on average than those deposited closer to the present, and this effect is compounded across the billions of years that life is believed to have existed. Most fossils are made up of the hard parts of an organism that have been recrystallized by minerals, preserving bone, wood, or shells in a material than can be harder or denser than in life. While the hard parts are the most likely to fossilize,
soft tissues Soft tissue connects and surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, fat, fibrous tissue, lymph and blood vessels, fasciae, and synovial membranes. Soft tissue is tissue in the body that is not ...
can also leave impressions on sediment before they fully
decompose Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is essen ...
, allowing non-mineralized parts of an organisms anatomy to be preserved. Even more rarely, a complete organism can be encased in sediment before decomposition, preserving it completely. While most fossils are body fossils (made of the actual body parts of a dead organism), some fossils can also consist of traces of the behaviour or life of organisms. This can include preserved
burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...
s, footprints or
coprolites A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name i ...
, which are grouped together and called
trace fossil A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...
s. However, only a small minority of all dead organisms will ever become fossils. Some things can destroy organisms before or even after fossilization, including
scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...
s,
decomposer Decomposers are organisms that break down dead organisms and release the nutrients from the dead matter into the environment around them. Decomposition relies on chemical processes similar to digestion in animals; in fact, many sources use the word ...
s, or
natural disaster A natural disaster is the very harmful impact on a society or community brought by natural phenomenon or Hazard#Natural hazard, hazard. Some examples of natural hazards include avalanches, droughts, earthquakes, floods, heat waves, landslides ...
s, and fossils can even be destroyed after they are formed by
taphonomic Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientist Ivan Efremov ...
processes. Even if a fossil survives burial, it can still be destroyed by
weathering Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...
if it is exposed and not collected. The habitat of an organism can also impact its chances of fossilization. Seafloors are more likely to fossilize than land, and rivers or lakes more likely to fossilize than mountains or deserts. Fossilized
teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
are very common, but are not always collected when they are found, and more complete fossils may be more likely to be collected, but they are generally rarer in absolute terms. Even after collection, fossils may not be studied for a long time. They may remain in
museum A museum is an institution dedicated to displaying or Preservation (library and archive), preserving culturally or scientifically significant objects. Many museums have exhibitions of these objects on public display, and some have private colle ...
storage in crates, be on display, or be otherwise unaccessible to scientists.


Geologic time

The earliest discussions in the field of geology centered around the possible origins of geological features and what implications these had on
Christianity Christianity is an Abrahamic monotheistic religion, which states that Jesus in Christianity, Jesus is the Son of God (Christianity), Son of God and Resurrection of Jesus, rose from the dead after his Crucifixion of Jesus, crucifixion, whose ...
. The concept of a
history of Earth The natural history of Earth concerns the development of planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to understanding of the main events of Earth's past, characterized by consta ...
had existed for a long time, and those who studies rocks of fossils had come to the idea of changes over time. However, in the beginning of the field of geology in the early 19th century, the most common explanation for causes of geological change were that they were the result of sedimentation during the
Biblical Flood The Genesis flood narrative (chapters 6–9 of the Book of Genesis) is a Hebrew flood myth. It tells of God's decision to return the universe to its pre- creation state of watery chaos and remake it through the microcosm of Noah's ark. The Bo ...
, rather than slow processes drawn out over millions of years. French naturalist
Georges Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...
and his contemporaries believed that the Earth was not recently created (as in
Young Earth Creationism Young Earth creationism (YEC) is a form of creationism which holds as a central tenet that the Earth and its lifeforms were created by supernatural acts of the Abrahamic God between about 10,000 and 6,000 years ago, contradicting established s ...
), nor had it been around forever. They instead believed that there was a vast "prehuman" or
antediluvian The antediluvian (alternatively pre-diluvian or pre-flood) period is the time period chronicled in the Bible between the fall of man and the Genesis flood narrative in biblical cosmology. The term was coined by Thomas Browne (1605–1682). The n ...
history. Cuvier was not the first to believe in a lengthy but finite age of the Earth, but he was the first to combine this idea with his study of fossils to suggest prehistoric events could be understood through the study of geology and the fossil record. Studies on rocks and their
stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...
continued, including the development of
geological map A geological map or geologic map is a special-purpose map made to show various geological features. Rock (geology), Rock units or stratum, geologic strata are shown by color or symbols. Bed (geology), Bedding planes and structural features such ...
s highlighting the relative ages of regional
geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
s, and it was still believed that the Biblical Flood was a primary explanation for the formation of these features. English geologist
Charles Lyell Sir Charles Lyell, 1st Baronet, (14 November 1797 – 22 February 1875) was a Scottish geologist who demonstrated the power of known natural causes in explaining the earth's history. He is best known today for his association with Charles ...
was among the first to propose that a great flood had not occurred, and this was supported by the existence of overlapping terrestrial and marine sediment layers. He observed that the twisting, uplifting and carving of geological features supported the idea that the crust was moving continuously, and the
sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
was also adjusting over time. This interpretation was not only supported by the differing levels of marine strata, but also by the shared commonality of fossils he found within them, even across large distances and at different levels above the sea. Combining these facts with his own previous work led Lyell to suggest some core principles of the history of the Earth. He suggested that here were progressive trends in the history of life, that geological history was continuously changing with periods of calm and chaos, and that the causes of these geological events were as much around in present day as in the deep past. Following the ongoing study of geology,
geologic formations A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...
, and the establishment of
geochronology Geochronology is the science of Chronological dating, determining the age of rock (geology), rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, ...
, the
geologic time scale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochro ...
was created to separate and categorize the vast history of Earth into a scale of named geochronologic units, defined and standardized by the
International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ...
. The age and duration of different units has changed over time following further restudy including
absolute Absolute may refer to: Companies * Absolute Entertainment, a video game publisher * Absolute Radio, (formerly Virgin Radio), independent national radio station in the UK * Absolute Software Corporation, specializes in security and data risk ma ...
and
relative dating Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e., estimated age). In geology, rock or superficial d ...
of different sediments, with the current standard recognizing four eons, ten eras, 22 periods, 37 epochs and 96 ages. Present day is recognized as the
Meghalayan The Meghalayan age is the name given in 2018, by the International Commission on Stratigraphy, to the current age or latest geologic age – or uppermost stage of the Quaternary. It is also the upper, or latest, of three subdivisions of the ...
age, of the
Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
epoch, of the
Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
period, of the
Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
era, of the
Phanerozoic The Phanerozoic is the current and the latest of the four eon (geology), geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and ...
eon. These geological time units are correlated globally through combinations of assigned times,
index fossils Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...
,
paleomagnetism Paleomagnetism (occasionally palaeomagnetism) is the study of prehistoric Earth's magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain ...
, and other methods, with the correlation of taxa with time being termed
biochronology In paleontology, biochronology is the correlation in time of biological events using fossils. In its strict sense, it refers to the use of assemblages of fossils that are not tied to stratigraphic sections (in contrast to biostratigraphy, where th ...
. Through biochronology, paleontological events such as the evolution, extinction, or
speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...
of a taxon can be established at a point in time, and features such as
mass extinction An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occ ...
s can be identified.


Extinction

Fossils have been documented from at least as far back as
Ancient Greece Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically r ...
. However, the belief of philosophers including
Plato Plato ( ; Greek language, Greek: , ; born  BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...
and
Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...
was that anything that existed had existed forever and would exist forever, or was along a continuum of perfection without any gaps. As a result of this fundamental belief, evidence of extinction was ignored or explained away by naturalists for most of recorded history. It was not until the work of Cuvier with the publication of his ''Recherches sur les ossemens fossiles'' (or ''Investigations on fossil bones''), that extinction was understood and considered the principal basis for paleontology as a science. By the early-mid 19th century, it was no longer controversial that fossil animals existed in a sequential order and as a result that fauna and flora were changing over time. Cuvier himself denied that there was any direct continuity from any of these fossils to organisms alive in the present day, and thus that all were extinct. However, he also did not believe the idea that any presently extant organisms had been alive in the past. Instead he believed that over time great "revolutions" occurred in which all living organisms went extinct, and new ones arose, which was consistent with belief in the Biblical Flood. It was not until English naturalist
Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...
suggested that extinction and evolution both occurred together, that a full explanation could be given for changes of life over time. The fossil record showed that there was not a predetermined length of time for which a particular organism (or group of organisms) existed, and it also gave evidence for periods where a large percentage of organisms went extinct at once, which could be the result of mass extinction events. Extinction can be seen as the final step of evolutionary change for any species. While modern biologists assess rates of extinction can be through the presence or absence of
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
in nature, paleontologists are limited in their understanding of this by the inherent rarity of fossils and the incompleteness of the fossil record. These difficulties make it more challenging to infer what extinction rates were in the past, and can make it difficult to differentiate between a true extinction and a "pseudoextinction", where one species evolves directly into another. Extinction of a species can occur from a variety of causes, and the intensity of extinction rates vary significantly over time. At least five mass extinction events are recognized to have occurred during the history of Earth, and it is also possible that the Earth is currently undergoing a
sixth extinction The Holocene extinction, also referred to as the Anthropocene extinction or the sixth mass extinction, is an ongoing extinction event caused exclusively by human activities during the Holocene epoch. This extinction event spans numerous families ...
as a result of human activity. However, mass extinction events only account for a small percentage of total species extinctions. Most extinctions occur as a result of other causes at differing times throughout Earth's history, which is sometimes called the
background extinction rate Background extinction rate (BER), also known as the normal extinction rate, refers to the standard rate of extinction in Earth's geological and biological history, excluding major extinction events, including the current human-induced Holocene ex ...
. For most organisms in the fossil record, it is impossible to determine the cause of extinction in particular or even general cases.


Evolution

For most of human history, philosophers, theologians, and other intellectuals believed that the world was perfectly ordered by divine forces and could not have come about from natural processes. There are exceptions such as the Greek philosopher Еmpеdoсlеs who thought that fossils may have come from organic life that had undergone change, but this was the exception. Most religious doctrines, including Christianity and
Judaism Judaism () is an Abrahamic religions, Abrahamic, Monotheism, monotheistic, ethnic religion that comprises the collective spiritual, cultural, and legal traditions of the Jews, Jewish people. Religious Jews regard Judaism as their means of o ...
, taught that the world was created by God as it currently exists, so life could not have progressed and the natural world was instead the product of
intelligent design Intelligent design (ID) is a pseudoscientific argument for the existence of God, presented by its proponents as "an evidence-based scientific theory about life's origins".#Numbers 2006, Numbers 2006, p. 373; " Dcaptured headlines for it ...
. The evolutionary significance of the fossil record was not initially recognized because individual fossils only show snapshots of evolutionary history. However, recognition of the ability for traits to be passed to later generations was used by French naturalist
Jean-Baptiste Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biologi ...
in the 19th century to argue for evolution. Early proponents of evolution initially believed that God had set the world in motion but let it progress naturally, while critics such as Cuvier thought that intermediate forms required would have been unable to survive and so rejected the possibility of evolution outright. Influenced by the writings of Lyell, Charles Darwin studied similarities in organisms during his time aboard the ''HMS Beagle'' which would eventually became the book ''
On the Origin of Species ''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life'')The book's full original title was ''On the Origin of Species by M ...
''. In it, Darwin proposed the concept of
natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...
which would become fundamental to the later theory of evolution. Darwin also suggested that gaps in the fossil record were the result of incomplete fossilization and that
transitional fossil A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross ...
s would eventually be found that would corroborate the theory of evolution. Paleontologists cannot use the
species concept A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and ...
s of modern biology due to limitations of working on fossils rather than living organisms. However, differences in the
morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
of organisms based on their fossil remains can be used to separate
phenotypes In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properti ...
. Once phenotypic differences in a population of organisms accumulate, they should become genetically isolated and thus separate species. Therefore, the phenotypes observed in fossils can be used as a proxy to infer differences between species throughout deep time. It is possible that these evolutionary and morphological changes occurred slowly and gradually as is hypothesized by
phyletic gradualism Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform and gradual.Eldredge, N. and S. J. Gould (1972)"Punctuated equilibria: an alternative to phyletic gradualism"In T.J.M. Schopf, ed., ''Models in P ...
, or that short bursts of rapid evolution occurred in
punctuated equilibrium In evolutionary biology, punctuated equilibrium (also called punctuated equilibria) is a Scientific theory, theory that proposes that once a species appears in the fossil record, the population will become stable, showing little evolution, evol ...
. Evidence for both methods of
macroevolution Macroevolution comprises the evolutionary processes and patterns which occur at and above the species level. In contrast, microevolution is evolution occurring within the population(s) of a single species. In other words, microevolution is the ...
are present in the fossil record, and the discovery of new fossils continuously helps to fill gaps in our understanding of the evolutionary history of life.


History

Cuvier is generally regarded as the first paleontologist, and the origins of paleontology as a science trace their origins directly to his demonstrations that fossils in stone were traces of organisms that were once alive but had gone extinct. Despite this, he was far from the first to write about fossils or make observations about things found in rock. Isolated comments from writers about fossils can be found going back to
classical antiquity Classical antiquity, also known as the classical era, classical period, classical age, or simply antiquity, is the period of cultural History of Europe, European history between the 8th century BC and the 5th century AD comprising the inter ...
. The
philosopher Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
Xenophanes Xenophanes of Colophon ( ; ; – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer. He was born in Ionia and travelled throughout the Greek-speaking world in early classical antiquity. As a poet, Xenophanes was known f ...
(6th century BCE) believed fossil shells represented life from the past, whereas Aristotle instead explained fossils as "vaporous exhalations". Aristotle's belief was later refined into the theory of a petrifying liquid by Arabic philosopher
Avicenna Ibn Sina ( – 22 June 1037), commonly known in the West as Avicenna ( ), was a preeminent philosopher and physician of the Muslim world, flourishing during the Islamic Golden Age, serving in the courts of various Iranian peoples, Iranian ...
and German philosopher
Albert of Saxony Albert of Saxony may refer to: * Albert, King of Saxony (1828–1902) * Albert I, Duke of Saxony (ca. 1175–1260) * Albert II, Duke of Saxony (ca. 1250–1298) * Albert III, Duke of Saxony (1443–1500) * Prince Albert of Saxony, Duke of Teschen ...
in the
middle ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...
. Chinese naturalist
Shen Kuo Shen Kuo (; 1031–1095) or Shen Gua, courtesy name Cunzhong (存中) and Art name#China, pseudonym Mengqi (now usually given as Mengxi) Weng (夢溪翁),Yao (2003), 544. was a Chinese polymath, scientist, and statesman of the Song dynasty (960 ...
also proposed a theory of
climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
around this time based on the presence of
petrified In geology, petrifaction or petrification () is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood typifies this proce ...
bamboo Bamboos are a diverse group of mostly evergreen perennial plant, perennial flowering plants making up the subfamily (biology), subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in th ...
in regions that in his time were too dry for bamboo. In unpublished notebooks, the Italian
polymath A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested o ...
justified an organic origin for the fossil shells available to him. His notes show observations of living mollusks and their ecology, the processes of
sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension 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 th ...
, and the recognition that the fossil shells had similar features, showed similar growth stages, and had similar pathologies to living mollusks. Da Vinci's study of sedimentation meant he understood why fossils were usually embedded in rocks, and his notes demonstrate a very modern interpretation of the origin of fossils. He rejected the Aristotelian theory of vapors and also did not believe that the Biblical Flood was the primary cause of fossil formation. Da Vinci's notebooks may have inspired others of the time to accept a biologic origin of fossils, but this belief was not accepted by everyone. In addition to his study of body fossils, da Vinci is also credited as the founder of the field of
ichnology A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...
, which is primarily concerned with
trace fossils A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...
and how they can provide insights into the behavior of extinct organisms. In the 17th century, naturalists like the Danish scientist
Nicolas Steno Niels Steensen (; Latinized to Nicolas Steno or Nicolaus Stenonius; 1 January 1638 – 25 November 1686 ) was a Danish scientist, a pioneer in both anatomy and geology who became a Catholic bishop in his later years. He has been beatified ...
and the English polymath
Robert Hooke Robert Hooke (; 18 July 16353 March 1703) was an English polymath who was active as a physicist ("natural philosopher"), astronomer, geologist, meteorologist, and architect. He is credited as one of the first scientists to investigate living ...
provided further discussions on the origins of fossils. The general belief was that fossils were of organic origin, but that they had been fossilized by petrifying liquids and moved into elevation by the Biblical Flood or some other means. Conversely, the English physician
Martin Lister Martin Lister (12 April 1639 – 2 February 1712) was an English natural history, naturalist and physician. His daughters Anne Lister (illustrator), Anne and Susanna Lister, Susanna were two of his illustrators and engravers. J. D. Woodley, 'L ...
completely rejected the possibility of organic fossil origins. The fossils available to Steno, da Vinci, and others mentioned above were primarily the easily-identifiable shells of marine animals, and their organic origin was a relatively straightforward inference. The fossils in England were from rocks dating to the
Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
or
Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...
and came from a variety of different organisms that bore no clear resemblance to modern organisms. Many explanations were suggested for the posible inorganic or organic origins of fossils, how they came to be lithified, and how they ended up far above the sea, but the ideas of extinction and deep time had not yet been developed, so an explanation eluded naturalists of the time. A significant moment in the history of paleontology was the publication of the
1796 Events January–March * January 16 – The first Dutch (and general) elections are held for the National Assembly of the Batavian Republic. (The next Dutch general elections are held in 1888.) * February 1 – The capital of Upper Can ...
paper ''On the species of living and fossil elephants'' by Georges Cuvier, which contained detailed evidence for extinction. Cuvier named the fossil taxon ''
Megatherium ''Megatherium'' ( ; from Greek () 'great' + () 'beast') is an extinct genus of ground sloths endemic to South America that lived from the Early Pliocene through the end of the Late Pleistocene. It is best known for the elephant-sized type spe ...
'', based on bones found in
Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...
. The large size of these bones made it unlikely that they were from an extant, but undiscovered, animal. Cuvier reached a similar conclusion regarding the fossils named the
mastodon A mastodon, from Ancient Greek μαστός (''mastós''), meaning "breast", and ὀδούς (''odoús'') "tooth", is a member of the genus ''Mammut'' (German for 'mammoth'), which was endemic to North America and lived from the late Miocene to ...
, with the uniqueness of these animals demonstrating that they belonged to species that were no longer alive and thus extinct. To further justify this conclusion, Cuvier extensively studied the fossils of
elephants Elephants are the Largest and heaviest animals, largest living land animals. Three living species are currently recognised: the African bush elephant (''Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian ele ...
and prove the distinction of
mammoths A mammoth is any species of the extinct elephantid genus ''Mammuthus.'' They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabi ...
from
Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...
and Europe from their living relatives. Presenting this work on the extinction of the
megafauna In zoology, megafauna (from Ancient Greek, Greek μέγας ''megas'' "large" and Neo-Latin ''fauna'' "animal life") are large animals. The precise definition of the term varies widely, though a common threshold is approximately , this lower en ...
, Cuvier termed the events that led to their disappearance "revolutions", contrasting with the idea of gradual change in the environment and the fauna within it. Of the three possibilities leading to the disappearance, Cuvier supported extinction over migration as well as over evolution as suggested by Lamarck, with his view that extinction and evolution were conflicting explanations. Cuvier also studied the comparative anatomy of both living and fossil organisms and developed a way to assess their morphological characters, which opened the door for developing an understanding of the animals of the past. Developments in the fields of stratigraphy and paleontology following the work of Cuvier became widespread throughout Europe, and the
classification Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...
of extinct organisms into different groups that included their living relatives also proliferated. While most of Cuvier's early studies had been on mammals, there were some fossils with no close living analogues such as the bird-like fossil reptile he called the '' Ptero-dactyle'' or the fish-like marine reptiles that were eventually named
ichthyosaur Ichthyosauria is an order of large extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of the Mesozoic era; based on fo ...
s. It was in
1822 Events January–March * January 1 – The Greek Constitution of 1822 is adopted by the First National Assembly at Epidaurus. * January 3 – The famous French explorer, Aimé Bonpland, is imprisoned in Paraguay on charges of espionage. ...
that
Henri Marie Ducrotay de Blainville Henri Marie Ducrotay de Blainville (; 12 September 1777 – 1 May 1850) was a French zoologist and anatomist. Life Blainville was born at Arques-la-Bataille, Arques, near Dieppe, Seine-Maritime, Dieppe. As a young man, he went to Paris to study a ...
, a former student of Cuvier, introduced the name ''paléontologie'' for the study of these ancient beings. He had earlier introduced the names ''paléozoologie'' and ''paléosomiologie'' for the studies of fossil animals and fossils in general, respectively, but the latter did not see widespread use and paleontology was the name generally adopted for the field by naturalists of the time. Some of the most significant discoveries of this early time in paleontology were made by
Mary Anning Mary Anning (21 May 1799 – 9 March 1847) was an English fossil collector, fossil trade, dealer, and palaeontologist. She became known internationally for her discoveries in Jurassic marine fossil beds in the cliffs along the English Cha ...
and her family, who uncovered skeletons from a variety of marine reptiles and other animals in the
Lyme Regis Lyme Regis ( ) is a town in west Dorset, England, west of Dorchester, Dorset, Dorchester and east of Exeter. Sometimes dubbed the "Pearl of Dorset", it lies by the English Channel at the Dorset–Devon border. It has noted fossils in cliffs and ...
region including ''
Ichthyosaurus ''Ichthyosaurus'' (derived from Greek () meaning 'fish' and () meaning 'lizard') is a genus of ichthyosaurs from the Early Jurassic (Hettangian - Pliensbachian) of Europe (Belgium, England, Germany and Portugal). Some specimens of the ichthy ...
'' and ''
Plesiosaurus ''Plesiosaurus'' (Greek: ' ('), near to + ' ('), lizard) is a genus of extinct, large marine sauropterygian reptile that lived during the Early Jurassic. It is known by nearly complete skeletons from the Lias of England. It is distinguishable by ...
''. These animals were geologically older than the mammals of Cuvier's earlier work, and this relative age became the study of stratigraphy which enabled scientists to date and order animals relative to one another in geologic time. The works of Cuvier and Lamarck on extinction and the history of life, and the works of Lyell and English geologist
Adam Sedgwick Adam Sedgwick FRS (; 22 March 1785 – 27 January 1873) was a British geologist and Anglican priest, one of the founders of modern geology. He proposed the Cambrian and Devonian period of the geological timescale. Based on work which he did ...
on geology, were all synthesized by Charles Darwin in his seminal works on the theory of evolution. He suggested that the history of life was full of gradual changes, with the constant presence of extinction acting as the driver evolution through natural selection. This was validated by multiple discoveries soon after Darwin began publishing. The discovery of the
theropods Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
''
Compsognathus ''Compsognathus'' (; Ancient Greek, Greek ''kompsos''/κομψός; "elegant", "refined" or "dainty", and ''gnathos''/γνάθος; "jaw") is a genus of small, bipedalism, bipedal, carnivore, carnivorous theropoda, theropod dinosaur. Members o ...
'' and ''
Archaeopteryx ''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird'') is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaîos''), meaning "ancient", and (''ptéryx''), meaning "feather" ...
'' demonstrated evidence for the progressive evolution of birds from other reptiles, which shifted paleontological study in the direction of studying the evolution of life. For a time paleontology was considered a sub-discipline of geology with relatively little study given to the biological aspects of the field, and paleontology was generally not treated as an important field of study of either science. Over the subsequent decades, geology and biology advanced to theory-based analysis while paleontology lagged behind as a field focused primarily on stratigraphy. This changed with the development of paleobiology in the second half of the
20th century The 20th century began on 1 January 1901 (MCMI), and ended on 31 December 2000 (MM). It was the 10th and last century in the 2nd millennium and was marked by new models of scientific understanding, unprecedented scopes of warfare, new modes of ...
. This shift was driven by conceptual changes in the study of evolution and
phylogenetics In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
and the emergence of new ways to study geology through biostratigraphy,
paleobiogeography Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...
,
taphonomy Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek language, Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientis ...
and
paleoclimatology Paleoclimatology ( British spelling, palaeoclimatology) is the scientific study of climates predating the invention of meteorological instruments, when no direct measurement data were available. As instrumental records only span a tiny part of ...
. Phylogenetics were developed as a way to quantitatively analyze and interpret the evolution and relationships of organisms, providing context and predictability for evolutionary processes and the impacts of mass extinctions and their recoveries.
Paleoecology Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...
itself has seen the emergence of subdisciplines including the field of taphonomy to study the nature of the fossil record. Emphasis was also given to the analysis of diversity and the distribution of taxa, the study of trace fossils, the understanding of
paleoenvironment Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...
s, and
conservation paleobiology Conservation paleobiology is a field of paleontology that applies the knowledge of the geological and paleoecological record to the conservation and restoration of biodiversity and ecosystem services. Despite the influence of paleontology on ecolo ...
. Advancements in technology and the analytical tools of other sciences have also been integrated into paleontology including
geochemical Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ...
analysis,
molecular biology Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...
, and other computer-aided visualization or analysis techniques. The heyday of paleontology was arguably in the
Victorian era In the history of the United Kingdom and the British Empire, the Victorian era was the reign of Queen Victoria, from 20 June 1837 until her death on 22 January 1901. Slightly different definitions are sometimes used. The era followed the ...
, with little substantial change since beyond the notable discoveries of new taxa. These on their own have done little to change our overall understanding of the history of life. However, the history of life is not just the story of evolutionary changes, and paleontology has increasingly broadened to include a wider variety of scientific questions. The sizes of the largest dinosaurs,
pterosaurs Pterosaurs are an extinct clade of flying reptiles in the Order (biology), order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosau ...
, or
arthropods Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
pose interesting questions to study in the fields of
biomechanics Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to Organ (anatomy), organs, Cell (biology), cells and cell organelles, using the methods of mechani ...
,
ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the ovum, egg to adult. The term can also be used to refer to t ...
, and physiology. Diversification and mass extinction can be predicted and better understood from the studies of phylogenetics, and as technologies and precision improve, the depth to which we understand life of the past will increase.


Applications

Paleontology both draws from and contributes to the fields of geology and biology, despite historically being dismissed as an undemanding science. Analysis and description of fossils allows the researchers to illustrate biological, geological, ecological and tectonic changes and phenomena which have implications for our understanding of science in the present. Many disciplines and areas of study interact with paleontology and overlap in some areas with the field. Through this overlap, paleontology has the ability to better our understanding of the origin, diversity and evolution of life, and can be used by other fields to investigate patterns in the fossil record. In the modern day, paleontology is viewed as important by researchers. Its study enables scientists to understand the history of life. It can explain different worlds of the past and the impact of a changing climate and biodiversity, and paleontology helps expand our understanding of both evolution and extinction. Subfields of paleontology also enable geologists to robustly establish the ages of various rock formations.


History of life

Paleontological discoveries have discussed the origins and history of life for centuries, with very little knowledge of life before the
Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...
for a significant amount of time. Fossils from prior to the Cambrian were limited to 2.1 billion year old fossilized
algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
and possibly "plants" until the discoveries of fauna in the Bitter Springs Group and Apex chert of Australia, the Mistaken Point Formation of Canada, and the
Doushantuo Formation The Doushantuo Formation (formerly transcribed as Toushantuo or Toushantou, from ) is a geological formation in western Hubei, eastern Guizhou, southern Shaanxi, central Jiangxi, and other localities in China. It is known for the fossil Lagers ...
of China, all of which have significantly expanded knowledge of the
Ediacaran biota The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organis ...
that includes a range of life from microscopic single-celled organisms to macroscopic multicellular life. Fossil discoveries have also improved knowledge about the Cambrian explosion with the discoveries of multiple new
lagerstätte A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserv ...
deposits. The
Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fos ...
was one of the first such deposits and has been further explored, and around 40 other Burgess-type localities are now known globally. These localities are filled with soft-bodied taxa that show the decline of the Ediacaran biota and the emergence of other kinds of
metazoa Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hol ...
n life. The refinement of Cambrian stratigraphy will also improve the understanding of these early faunas and how they changed over time. Through advances in paleontology many other evolutionary paths have become better understood even in more recent life. The
evolution of birds The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. Birds are categorized as a Class (biology), biological class, Aves. For more than a century, the small theropod ...
is now understood to have occurred from gradual evolutionary changes in
saurischian Saurischia ( , meaning "reptile-hipped" from the Greek ' () meaning 'lizard' and ' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithis ...
dinosaurs up to the point where it is difficult to draw a line between what dinosaurs are or are not birds. The origins of dinosaurs themselves are better understood from the discoveries of multiple near-dinosaur taxa. Discoveries within the
Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
of fossil mammals have allowed for the evolution of whales to be nearly completely understood, with the fully terrestrial
mesonychid Mesonychidae (meaning "middle claws") is an extinct family of small to large-sized omnivorous-carnivorous mammals. They were endemic to North America and Eurasia during the Early Paleocene to the Early Oligocene, and were the earliest group of la ...
s becoming gradually
amphibious Amphibious means able to use either land or water. In particular it may refer to: Animals * Amphibian, a vertebrate animal of the class Amphibia (many of which live on land and breed in water) * Amphibious caterpillar * Amphibious fish, a fish ...
before becoming aquatic swimmers. Relatives of modern whales such as ''
Basilosaurus ''Basilosaurus'' (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehisto ...
'' were obligate swimmers, but even then had not developed the
bauplan A body plan, (), or ground plan is a set of morphological features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many. This term, usually applied to animals, envisages a "blueprin ...
of modern
cetacean Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
s that occurred over further gradual evolution. The evolution of reptile groups such as ichthyosaurs and
turtles Turtles are reptiles of the order Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtle ...
, while still controversial, is much better understood with finds such as the early incompletely-shelled turtle ''
Proganochelys ''Proganochelys'' is a genus of extinct, primitive stem-turtle. ''Proganochelys'' was named by Georg Baur in 1887 as the oldest turtle in existence at the time. The name ''Proganochelys'' comes from the Greek language, Greek word ''ganos'' meani ...
''.
Human evolution ''Homo sapiens'' is a distinct species of the hominid family of primates, which also includes all the great apes. Over their evolutionary history, humans gradually developed traits such as Human skeletal changes due to bipedalism, bipedalism, de ...
is also much better understood from progress in paleontology, including both the evolution of
hominid The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); '' Gorilla'' (the ...
s from basal
primates Primates is an order of mammals, which is further divided into the strepsirrhines, which include lemurs, galagos, and lorisids; and the haplorhines, which include tarsiers and simians ( monkeys and apes). Primates arose 74–63  ...
as well as the speciation and origins of humans within the hominids. Fossils of ''
Australopithecus ''Australopithecus'' (, ; or (, ) is a genus of early hominins that existed in Africa during the Pliocene and Early Pleistocene. The genera ''Homo'' (which includes modern humans), ''Paranthropus'', and ''Kenyanthropus'' evolved from some ''Aus ...
'' and ''
Ardipithecus ''Ardipithecus'' is a genus of an extinct hominine that lived during the Late Miocene and Early Pliocene epochs in the Afar Depression, Ethiopia. Originally described as one of the earliest ancestors of humans after they diverged from the chim ...
'' show that humans never transitioned through an
ape Apes (collectively Hominoidea ) are a superfamily of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and Europe in prehistory, and counting humans are found global ...
-like stage, instead being bipedal with adaptations for
arboreal locomotion Arboreal locomotion is the animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolution, evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are e ...
. ''Adripithecus'' is known from lowland
forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...
environments, and not grasslands, suggesting the origins of humanity within a variable and unpredictable habitat. The evolution of humans within the genus ''
Homo ''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...
'' is similarly complex and does not follow a clean linear path as sometimes described. Some species of ''Homo'' may have overlapped in time and place with others, but all show that then evolution of the genus was likely in
Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
. Advancements and new discoveries have also shown that the
neanderthal Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinction, extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle Pleistocene, Middle to Late Plei ...
s were a complex society with the use of
tools A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ...
,
clothes Clothing (also known as clothes, garments, dress, apparel, or attire) is any item worn on a human human body, body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin s ...
, and having their own
mythology Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...
.
DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
from neanderthals and humans show substantial differences, but also that there was interbreeding between populations.


Extinction events

The idea of a mass extinction has been around since the beginning of paleontology and is generally accepted as true events that drive the evolution of life. However, the question of what makes an extinction event a "mass extinction" is still uncertain. On the scale of geologic time, mass extinction events happen rapidly, and such rapid events can be caused by both gradual environmental processes and large-scale catastrophes. A notable exception to this rule is the Cretaceous-Paleogene extinction event, which is believed to have been caused by an
asteroid impact An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effe ...
which caused global
wildfires A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...
and a disruption of the
nutrient cycle A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyc ...
in the ocean. If this is the case, it would be an unprecedentedly rapid extinction event, occurring over the course of one or a few years. However, even this extinction's cause is debated. Some have suggested that it was caused by
marine regression A marine regression is a geological process occurring when areas of submerged seafloor are exposed during a drop in sea level. The opposite event, marine transgression, occurs when flooding from the sea covers previously-exposed land. Descript ...
or
volcanism Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a he ...
that occurred near or at the same time as an impact. No other extinction events can be linked clearly with an extra-terrestrial cause.
Glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...
and subsequent
global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...
has been suggested as a cause for the
Late Ordovician mass extinction The Late Ordovician mass extinction (LOME), sometimes known as the end-Ordovician mass extinction or the Ordovician–Silurian extinction, is the first of the "big five" major mass extinction events in Earth's history, occurring roughly 445 mill ...
, and the volcanic activity of the
Siberian Traps The Siberian Traps () are a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the trap rock, traps is one of the largest known Volcano, volcanic events in the last years ...
large igneous province A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive ( sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The format ...
has been suggested as the primary cause for the Permian-Triassic mass extinction. The causes of the
Late Devonian mass extinction The Late Devonian mass extinction, also known as the Kellwasser event, was a mass extinction event which occurred around 372 million years ago, at the boundary between the Frasnian and Famennian ages of the Late Devonian period.Racki, 2005McGh ...
and the Triassic-Jurassic mass extinction remain mostly uncertain to this day. The period of ecological recovery following a mass extinction is also a significant time for biodiversity and
adaptive radiation In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic int ...
. The term "disaster species" has been applied to the organisms that follow an ecological disruption, and there are many known from the fossil record. Following the Cretaceous-Paleogene extinction, there is a large spike in the abundance of fossil
fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
s that is interpreted as an early post-extinction flora that would later be overtaken by different floral communities. There is a similarly rapid diversification of small, generalist mammals for the first 3 million years before more diverse faunal communities evolved. However, not all mass extinctions have similarly rapid diversification events. The recovery period following the Permian-Triassic extinction took up to 10 million years. The recovery of ecosystems from mass extinctions involves the evolution of novel ecological relationships between groups of animals that would not have been possible in the pre-extinction ecosystem.


Biostratigraphy

Fossils have been used for stratigraphic correlation since at least the 18th century. Observed changes in the fossils found through geologic time led to the principle of
ecological succession Ecological succession is the process of how species compositions change in an Community (ecology), ecological community over time. The two main categories of ecological succession are primary succession and secondary succession. Primary successi ...
, however this study was not elaborated on until the 1960s. The first and last appearance of a taxon in the fossil record can be used to compare the relative ages of different
lithographic Lithography () is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by the German ...
sections of sediment. This principle allows for relative ages of different sediments to be determined more precisely. These "
index fossil Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...
s" are combined with measurements of
volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, produced during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to r ...
, paleomagnetic reversals, or pre-dated sediments to make precise measurements of geologic time. For example, the
Jurassic Period The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. The Jurassic constitutes the second and m ...
was named and defined based on ten main subdivisions identified through the English and French assemblages of
ammonites Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...
, some of which are still in use today. Biostratigraphy is also applied to the analysis of
stratotype In geology, a stratotype or type section is the physical location or outcrop of a particular reference exposure of a stratigraphic sequence or stratigraphic boundary. If the stratigraphic unit is layered, it is called a stratotype, whereas the ...
sections and boundaries of geologic time units. It can also use the first or last appearance date of a taxon to establish time periods that are independent of their constituent strata. The geologic time scale is based primarily on the biostratigraphy (correlating strata) and equivalent biochronology (correlating times) of the appearance and disappearance of various fossil taxa. Some factors can introduce uncertainty into this process including the quality or quantity of sampled fossils. Different graphical and numerical methods are used in the construction of the geologic time scale. Even the
Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...
, which is poorly represented through fossils, can be assessed using biostratigraphy in combination with
chemostratigraphy Chemostratigraphy, or chemical stratigraphy, is the study of the chemical variations within sedimentary sequences to determine stratigraphic relationships. The field is relatively young, having only come into common usage in the early 1980s, but ...
and absolute dating. The biostratigraphy of the
Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...
and
Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...
is based primarily on fossils of
graptolites Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through th ...
and
conodonts Conodonts, are an extinct group of marine jawless vertebrates belonging to the Class (biology), class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning "cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known ...
. Other common groups used in zonation include ammonites,
foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...
, and plant pollen, where it is preserved.


Classification

The adoption of phylogenetics into paleontology may be one of the most significant changes in evolutionary biology. Biological classification through phylogenetics is able to
quantitatively Quantitative research is a research strategy that focuses on quantifying the collection and analysis of data. It is formed from a deductive approach where emphasis is placed on the testing of theory, shaped by empiricist and positivist philos ...
describe the relatedness of organisms through reconstructions of evolutionary trees. Phylogenetics was first applied to the fields of
entomology Entomology (from Ancient Greek ἔντομον (''éntomon''), meaning "insect", and -logy from λόγος (''lógos''), meaning "study") is the branch of zoology that focuses on insects. Those who study entomology are known as entomologists. In ...
and
ichthyology Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...
, winning favor after extensive debates. Phylogenetic systematics is able to test and retest hypotheses of classification, with results being displayed in the form of
cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
s. The broad adoption of phylogenetics also coincided with the advent of molecular biology, with computational analyses able to combine the two advancements and create phylogenetic trees based on the genetics of organisms. Classification systems have also shifted in favor of phylogenetics, with the Linnean classification scheme being recognized as an imperfect method of organization that resulted in the general abandonment of most
taxonomic rank In biology, taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of or ...
s due to their inconsistency and lack of true description of evolution. Further applications of classification in paleontology include more focused issues targeting the distinction between
microevolution Microevolution is the change in allele frequencies that occurs over time within a population. This change is due to four different processes: mutation, selection ( natural and artificial), gene flow and genetic drift. This change happens over ...
and macroevolution. Microevolution is the interpretation of how evolution impacts the ability of single individuals to survive over others, while macroevolution focuses on the ability of species to survive over others. While some viewpoints believe that microevolution and macroevolution are separate processes, with morphological change arising from speciation rather than gradual
anagenesis Anagenesis is the gradual evolution of a species that continues to exist as an interbreeding population. This contrasts with cladogenesis, which occurs when branching or splitting occurs, leading to two or more lineages and resulting in separate ...
of a population, others believe that all scales of individuals and species are affected by natural selection. The clearest examples of evolution into species arises from geographic isolation, but there is an ongoing discussion around the importance of biotic versus
abiotic In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them und ...
factors in evolution.


Subdisciplines

Paleontology overlaps and integrates with many other disciplines of science into fields that focus on more specific topics. The overlap of paleontology with biology, paleobiology, includes studies on macroevolution, extinction, speciation, diversification, morphology, biogeography, phylogeny, paleoecology, molecular paleontology, taphonomy, and
evolutionary developmental biology Evolutionary developmental biology, informally known as evo-devo, is a field of biological research that compares the developmental biology, developmental processes of different organisms to infer how developmental processes evolution, evolved. ...
. Many subdisciplines of paleontology are focused on specific groups of organisms: invertebrate paleontology is the study of fossil
invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...
; vertebrate paleontology is the study of fossil
vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...
;
paleoalgology Paleophycology (also once known as paleoalgology) is the subdiscipline of paleobotany that deals with the study and identification of fossil algae and their evolutionary relationships and ecology. The field is very important in the science of pal ...
is the study of fossil algae;
paleobotany Paleobotany or palaeobotany, also known as paleophytology, is the branch of botany dealing with the recovery and identification of plant fossils from geological contexts, and their use for the biological reconstruction of past environments ( pal ...
is the study of fossil plants;
paleoentomology The most recent understanding of the evolution of insects is based on studies of the following branches of science: molecular biology, insect morphology, paleontology, insect taxonomy, evolution, embryology, bioinformatics and scientific computing ...
is the study of fossil
insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...
;
paleoherpetology Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (incl ...
is the study of fossil reptiles and
amphibians Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...
;
paleoichthyology Fish began evolving about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish linea ...
is the study of fossil
fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
;
paleomalacology Malacology, from Ancient Greek μαλακός (''malakós''), meaning "soft", and λόγος (''lógos''), meaning "study", is the branch of invertebrate zoology that deals with the study of the Mollusca (molluscs or mollusks), the second-largest ...
is the study of fossil
mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...
;
paleomammalogy In zoology, mammalogy is the study of mammals – a class of vertebrates with characteristics such as homeothermic metabolism, fur, four-chambered hearts, and complex nervous systems. The archive of number of mammals on earth is constantly growin ...
is the study of fossil mammals;
paleomycology Paleomycology is the study of fossil fungi. Paleomycology is considered a subdiscipline of paleobotany, centered on mushrooms, fungal spores, and hyphae preserved in sediment layers and rock. Fungi have been found in the palaeoecological record as ...
is the study of fossil
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
;
paleomyrmecology Myrmecology (; from Greek: μύρμηξ, ''myrmex'', "ant" and λόγος, ''logos'', "study") is a branch of entomology focusing on the study of ants. Ants continue to be a model of choice for the study of questions on the evolution of social ...
is the study of fossil
ants Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...
;
paleornithology Paleornithology, also known as avian paleontology, is the scientific study of bird evolution and fossil birds. It is a hybrid of ornithology and paleontology. Paleornithology began with the discovery of ''Archaeopteryx''. The reptilian relationsh ...
is the study of fossil birds;
paleoprimatology Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship ...
is the study of fossil primates; and
paleozoology Palaeozoology or paleozoology ( Greek: παλαιόν, ''palaeon'' "old" and ζῷον, ''zoon'' "animal") is the branch of paleontology and evolutionary biology that specifically deal with the study of prehistoric organisms from the kingdom ...
is the study of fossil animals. Paleontology in general also overlaps with studies on growth,
paleoanthropology Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinsh ...
, many fields that focus on the Earths climatic and geographic past,
histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...
, ichnology,
pathology Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...
and forensics, and taphonomy, forming the subdisciplines described below.


Paleoanthropology

Paleoanthropology is a field of study that focuses on the evolutions of humans. The field can trace its origins to the works of German naturalist
Johann Blumenbach Johann Friedrich Blumenbach (11 May 1752 – 22 January 1840) was a German physician, naturalist, physiologist and anthropologist. He is considered to be a main founder of zoology and anthropology as comparative, scientific disciplines. He has be ...
in the late 18th century and then the discovery of a neanderthal in the mid 19th century though it only took its modern form as the study of human evolution following
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
with the acceptance of evolutionary biology. Paleoanthropology utilizes information on humans drawn from both fossils and
archaeology Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...
to interpret the rise and spread of humans. Beliefs were that only a single species of hominid was present at any one time, forming a natural progression to modern humans, considering the diverse groups of species proposed as
synonyms A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...
. Discoveries showed that this belief was not correct, with human evolution displaying a complex and uncertain arrangement of individuals, populations, and species with the advent of phylogenetic analyses. ''Ardipithecus'' is one of the oldest known of the human branch of hominids, having lived 4.4 million years ago and only found in 1994. Species of the genus ''Australopithecus'' from across Africa have been named since the 1970s are slightly younger, but already show the bipedal stance of modern humans. From ''Australopithecus'' likely evolved both ''Homo'' and the more robust hominid ''
Paranthropus ''Paranthropus'' is a genus of extinct hominin which contains two widely accepted species: ''Paranthropus robustus, P. robustus'' and ''P. boisei''. However, the validity of ''Paranthropus'' is contested, and it is sometimes considered to be sy ...
'', which is unlike modern humans in build but lived alongside early humans for some time. It is known that early humans were capable of making and using tools from the discoveries of fossils of ''
Homo habilis ''Homo habilis'' ( 'handy man') is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.4 million years ago to 1.65 million years ago ( mya). Upon species description in 1964, ''H. habilis'' was highly ...
'' in places where stone tools had previously been found. The earliest known stone tools are from around 3.3 million years ago, and while they are often associated with ''Homo'' it is also possible that the coexisting species ''
Australopithecus garhi ''Australopithecus garhi'' is a species of australopithecine from the Bouri Formation in the Afar Region of Ethiopia 2.6–2.5 million years ago (mya) during the Early Pleistocene. The first remains were described in 1999 based on several skele ...
'' was a toolmaker. There is reluctance to believe that a australopith was capable of making and using tools, but the origins of ''Homo'' are unclear and there is little that can be used to distinguish tool-making from non-tool-making hominids when fossils and tools are not found together. The first humans to show a more slender modern bauplan are those of ''
Homo ergaster ''Homo ergaster'' is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene. Whether ''H. ergaster'' constitutes a species of its own or should be subsumed into '' H. erectus'' is an ongoing and unresol ...
'', which is sometimes considered part of African ''
Homo erectus ''Homo erectus'' ( ) is an extinction, extinct species of Homo, archaic human from the Pleistocene, spanning nearly 2 million years. It is the first human species to evolve a humanlike body plan and human gait, gait, to early expansions of h ...
'', from around 1.6 million years ago. Once the modern body form evolved, humans spread far beyond Africa, spreading across
Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
from which evolved ''
Homo heidelbergensis ''Homo heidelbergensis'' is a species of archaic human from the Middle Pleistocene of Europe and Africa, as well as potentially Asia depending on the taxonomic convention used. The species-level classification of ''Homo'' during the Middle Pleis ...
'' and ''
Homo neanderthalensis Neanderthals ( ; ''Homo neanderthalensis'' or sometimes ''H. sapiens neanderthalensis'') are an extinct group of archaic humans who inhabited Europe and Western and Central Asia during the Middle to Late Pleistocene. Neanderthal extinctio ...
''. Though the diversity of neanderthals is uncertain, sites have been found that show they had a burial culture and a rich technological record. The similarities between ''Homo sapiens'' and these older or coexisting species makes it difficult to determine what made modern humans unique.


Paleobiogeography

Paleobiogeography is a very similar field to
biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...
but focuses instead on fossils rather than modern organisms. Both fields work to explain the differences in flora and fauna between different locations, rather than the expectation that regions of similar climate and habitat would house the same organisms. Biogeography relies on
exploration Exploration is the process of exploring, an activity which has some Expectation (epistemic), expectation of Discovery (observation), discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organis ...
, both as an exploratory tool to understand the world, but also the physical act of travelling to different places to observe differences. Paleobiogeography is named with the prefix "paleo" to differentiate in its use of the fossil record to study biogeography, which means that paleobiogeography suffers from the same issues as other paleontological fields regarding the limitations of the fossil record. It was established as a geoscience from the recognition and acceptance of the theory of
continental drift Continental drift is a highly supported scientific theory, originating in the early 20th century, that Earth's continents move or drift relative to each other over geologic time. The theory of continental drift has since been validated and inc ...
that was hinted at by the discoveries of similar fossils on now-distance
continent A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
s during the 19th century. Paleobiogeography involves studying the history of life, but is relevant for the study of evolutionary, geological, and ecological changes as external factors such as biogeography are one of the two drivers of evolution. Ecological processes can be studied that cause speciation or regulate diversity, and these differences across location can be tied to geological processes like plate tectonics and climate change. Modern biogeography has the advantage of being able to study molecular markers and more thoroughly study small spatial and temporal regions creating a better picture of a specific environment. Paleobiogeography on the other hand is capable of studying very long timescales, able to track history beyond just the modern era. Flora and fauna may be affected by small-scale cycles as well as broader effects that cannot be seen on a limited timescale, so paleobiogeography can provide a more complete picture of patterns and processes. Through the fossil record, paleobiogeography can monitor the evolution and coevolution of life on Earth, associating patterns with geological events and over long timescales, working with the field of biogeography to understand biogeographical processes.


Paleobiology

Paleobiology is the study of the biology of extinct organisms. As a topic it has been around since the beginning it paleontology itself, as fossils are the remains of extinct organisms, but the areas of research covered by paleobiology have changed to capture much more theoretical thinking, studying the biological aspects of paleontology rather than geological topics like stratigraphy. This means there is a particular focus on evolution, adaptation, ecology, function, and behavior in paleobiology, especially of invertebrates which are far more common in the fossil record. Darwin's work on evolution was largely paleobiological in nature, drawing from paleontology, geology and biology, but also pushed paleontology into the background as the incompleteness of the fossil record became a hindrance to advancements in evolution. The first use of "paleobiology" as a word came in
1893 Events January * January 2 – Webb C. Ball introduces railroad chronometers, which become the general railroad timepiece standards in North America. * January 6 – The Washington National Cathedral is chartered by Congress; th ...
, but it was the work of
Othenio Abel Othenio Lothar Franz Anton Louis Abel (20 June 1875 – 4 July 1946) was an Austrian paleontologist and evolutionary biologist. Together with Louis Dollo, he was the founder of " paleobiology" and studied the life and environment of fossilized ...
in the 1910s that established "päleobiologie" as the study of biologically informed paleontology.
Franz Nopcsa Franz may refer to: People * Franz (given name) * Franz (surname) Places * Franz (crater), a lunar crater * Franz, Ontario, a railway junction and unorganized town in Canada * Franz Lake, in the state of Washington, United States – see Fran ...
is also understood to have been a pioneer of paleobiology, and one of the first paleontologists to use histology and the interpret the paleophysiology of extinct animals. Biological questions did not change the field of paleontology greatly until the general transformation of the field in the 1950s and 1960s with new approaches to the fossil record and a differing view on the place of paleontology as a discipline. Paleontology was no longer seen as a subdivision of geology but instead as a field of biology or a field of its own, able to be grounded in theoretical thinking and assessed numerically. Paleontology was suggested to be educated as two separate areas: stratigraphy and paleobiology, with significant overlap and incerconnection. Throughout following decades paleobiology would expand to encompass many theoretical fields related to evolution or extinction, and become a feature of museums and
universities A university () is an educational institution, institution of tertiary education and research which awards academic degrees in several Discipline (academia), academic disciplines. ''University'' is derived from the Latin phrase , which roughly ...
supporting the connection between paleontology and biology. Many of the fields of paleontology can be seen as part of the study of paleobiology, and paleontologists themselves may be better referred to as paleobiologists. Evolution and paleoecology are large parts of the change towards paleobiology and major areas of study and advancements of the field. Theoretical thinking and analysis of evolution has advanced and improved applications of the fossil record. Studies of taphonomy, evolutionary paleoecology, diversity, behavior, trace fossils, and the paleoenvironment all fall under the breadth of paleoecology. Paleobiology is able to inform on questions about the life appearances of organisms, their ways of communicating or reproducing, their growth, and how they survived and died out. Effective paleobiology requires knowledge of biological fields (evolution,
genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...
,
systematics Systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: phylogenetic trees, phylogenies). Phy ...
, evolutionary developmental biology, biogeography, ecology,
biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...
), geological fields (
sedimentology Sedimentology encompasses the study of modern sediments such as sand, silt, and clay, and the processes that result in their formation (erosion and weathering), transport, deposition and diagenesis. Sedimentologists apply their understanding of m ...
, stratigraphy, Earth history, isotopes,
geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ...
, taphonomy),
statistics Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...
and applied math, and often even
computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...
. Findings and studies in biology are relevant and applicable to paleontology, and as a result the findings of paleontology become relevant to biology. The available information to study between the two fields is different, forcing paleontological studies to be more integrated while biological studies are more focused, but this is an opportunity for collaborative work.


Paleoclimatology

Paleoclimatology is the study of the ancient
climate Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...
s, and is a "paleo-science" alongside paleoecology and
paleoceanography Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment model ...
. Studies on the climate before and during the Quaternary, where direct measurements become available, are beginning to converge in scope, but the term "paleoclimatology" remains often restricted to the former. Before the identification and acceptance of plate tectonics, paleoclimatology had been applied from the observation that fossils were sometimes found where the climate was currently not suitable to that organism. Little discussion was had about the changing of the climate beyond the
Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago. Ice sheets covered m ...
, so paleoclimatology was restricted to the climate of the Quaternary. Inconsistencies between climate-significant rocks and current geography were not able to be reconciled until plate tectonics demonstrates that
climate zone Climate zones are systems that categorize the world's climates. A climate classification may correlate closely with a biome classification, as climate is a major influence on life in a region. The most used is the Köppen climate classification ...
s were constant but the landmasses beneath them would change. Indicators of the paleoclimate could be found in certain types of rocks, which coupled with reconstructions of the paleogeography showed that climate zones in the past were roughly the same as today, with exceptions. During the time of the supercontinent Pangaea, arid regions were believed to be generally lower in
latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...
that at other times in the past, which would be explained by the
monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...
al nature of the continent in the 1970s and the understanding that atmospheric circulation of monsoons also affected the regionality of climates.
Ocean drilling Offshore drilling is a mechanical process where a wellbore is drilled below the seabed. It is typically carried out in order to explore for and subsequently extract petroleum that lies in rock formations beneath the seabed. Most commonly, the ter ...
of core samples from the seabed were then used to identify
isotopes Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), but ...
that could examine the proportions of
oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...
and
carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
over time to illustrate the warmth and coldness of ocean waters. In some sense, global paleoclimatology would not be possible without these ocean drilling programs. Numerical modelling of the paleoclimate was employed to further the field, though it struggles with the polar regions and the climate of continental interiors. Further development of paleoclimatology will likely focus on the impact to humans of the alterations to the climate that are occurring, and use information from the past to make predictions about the future.


Paleoecology

Paleoecology is a diverse field of paleontology that relates to the reconstruction of lifestyles and
ecosystems An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
of ancient life. While we know much about the evolution of life, less is understood about the interactions and behavior of organisms. The large amount of
speculation In finance, speculation is the purchase of an asset (a commodity, good (economics), goods, or real estate) with the hope that it will become more valuable in a brief amount of time. It can also refer to short sales in which the speculator hope ...
involved in paleoecological interpretations means it may be disregarded at times, but a developing use of numerical and statistical techniques allows for quantitative assessments of paleoecological hypotheses. Paleoecology also investigates the long-term changing of ecologies and the balancing of chemical, biological, and physical changes of the world. Fossil animals and plant do not normally preserve in completion or in their undisturbed habitats, with
scavenging Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding be ...
, erosion, or transportation complicating their interpretation. The study of these complications from fossilization is taphonomy, which is its own significant and developing field of paleontology. The combination of reconstructions of ancient environments with the evolution of these environments over time is termed evolutionary paleoecology. Global patterns of diversity can be investigated through paleoecology, suggesting large bursts of diversification and the temporal separation of major faunas forms. However, these interpretations of changing diversity may be due to biases towards the preservation and discovery of more recent environments over older ones, where the field of taphonomy can become significant. Paleoecology has been able to identify several large-scale patterns in evolution and different faunas. It has been interpreted that communities living nearshore exhibit earlier diversification before spreading to offshore environments, or that tropical latitudes exhibit greater diversification. A largely
detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...
-feeding Cambrian fauna appears to be replaced by a suspension-feeding Paleozoic fauna, before itself being replaced by a modern fauna of marine invertebrates, though these faunas and their distinctiveness have also been questioned. Some communities show very little modification over time in a form of statis with stable composition, which changes during brief periods of turnover before stabilizing again. Competition and coevolution driving evolution may be studied through the fossil record, as well as predation and other forms of species interactions. The study of trace fossils, ichnology, also related to paleoecology as the study of fossils arising from behavioral patterns in organisms. Paleobiogeography, paleoclimatology and conservation paleobiology are also related fields of paleoecology, with the latter in particular being relevant to policies that attempt to preserve
biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...
.


Paleohistology

Paleohistology is the study of the hard tissues of fossils, analogous to the field of histology that studies biological tissues. The field is comparatively restricted as fossils preserve only superficial tissue structure and not molecules that can be found in modern histology, but it still has a long history following the use of
microscopes A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
to study both living and extinct organisms. Fossilization changes the composition of bones and to a lesser extent teeth, though their histology can still be examined through
thin section In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron ...
s. The first use of thin sections in studying tissues in fossils was that of
Richard Owen Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomy, comparative anatomist and paleontology, palaeontologist. Owen is generally considered to have been an outstanding naturalist with a remarkabl ...
in a set of volumes in the 1840s that included dinosaurs and pterosaurs, which was simultaneously the first large comparative study of hard tissue histology. The microscopic structure of the bones, dermal armor, and teeth of early vertebrates and fossil fish was studies soon after, though polished bone surfaces were used rather than thin sections. The hard tissue structure of these early vertebrates has been used to classify them and separate jawless vertebrates (
ostracoderm Ostracodermi () or ostracoderms is an informal group of vertebrate animals that include all armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic (excluding jawed fishes and ...
s) from those with jaws such as
placoderms Placoderms (from Ancient Greek πλάξ 'plax'', ''plakos plate' and δέρμα 'dermaskin') are vertebrate animals of the class Placodermi, an extinct group of prehistoric fish known from Paleozoic fossils during the Silurian and the Dev ...
and
acanthodian Acanthodii or acanthodians is an extinct class of Gnathostomata, gnathostomes (jawed fishes). They are currently considered to represent a paraphyletic Evolutionary grade, grade of various fish lineages Basal (phylogenetics), basal to extant tax ...
s. Similarly, the paleohistology of
tetrapods A tetrapod (; from Ancient Greek τετρα- ''(tetra-)'' 'four' and πούς ''(poús)'' 'foot') is any four- limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all extant and extinct amphibians and amniotes, with the lat ...
has been used as evidence of both their classifications and their function. The internal structure of bones of many tetrapods can be used to identify their age quantitatively through the count of growth arrest lines. Paleohistology combines structural knowledge with functional interpretations and evolutionary processes to help understand evolution.


Paleopathology

Paleopathology is the study of ancient
disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...
, with the clarification that "disease" is not limited to
pathogens In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ...
but also any other impairments that can impact health. Though paleopathology is most often discussed in the context of archaeology and human history, it has also included the study of pathologies in any fossil organism since the word was first introduced by Robert Schufeldt in
1892 In Samoa, this was the only leap year spanned to 367 days as July 4 repeated. This means that the International Date Line was drawn from the east of the country to go west. Events January * January 1 – Ellis Island begins processing imm ...
. It is important to separate pathological conditions from alterations that have arisen due to taphonomy, and from that distinction modern
diagnostic Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...
techniques can be used to interpret the causes and impacts of pathologies in fossil organisms. Biomolecular studies have been able to isolate genetic material in fossil animals and humans to identify specific pathogens, and questioning the strength of these identifications has led to re-evaluations of the history of disease in humans and a more nuanced approach towards the study of disease in humans. Multiple factors can cause skeletal lesions that preserve well in fossils and it can be difficult to distinguish these causes due to not being able to confidently identify causes of mortality and predispositions for vulnerability. Most of the focus of paleopathology remains on human disease, though the field of animal paleopathology emerged in 1999 and expanded to cover much of the same scope of studies as human paleopathology. Specific studies into the
stress fractures A stress fracture is a Mechanical fatigue, fatigue-induced bone fracture caused by repeated Stress (mechanics), stress over time. Instead of resulting from a single severe impact, stress fractures are the result of accumulated injury from repeat ...
in the bones of dinosaurs have used their presence and distribution to identify the activity levels of the impacted animals such as running, migrating, or restraining prey.


Paleophysiology

Paleophysiology is the study of how ancient life coped with its chemical and physical surroundings. Much is known about
physiological Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...
changes on a short time scale, but less so about long-term responses including genetic modification. Paleophysiological analysis can investigate how species evolved or went extinct from gradual or rapid environmental change and apply that to modern scenarios to predict responses in the future. Past geological records can be found that resemble those predicted for the future. Extinctions of ancient organisms tend to be selective to certain traits like
metabolic rate Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...
, temperature tolerance,
photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...
and
homeostasis In biology, homeostasis (British English, British also homoeostasis; ) is the state of steady internal physics, physical and chemistry, chemical conditions maintained by organism, living systems. This is the condition of optimal functioning fo ...
, but much is not yet understood about the physiology of ancient organisms. The most useful tool for assessing paleophysiology is through the studies of "
living fossils A living fossil is a deprecated term for an extant taxon that phenotypically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the ...
" that has presumably changed very little physiologically over long periods of time and therefor can be used to indicate paleophysiological conditions. It remains largely unknown how calcifying organisms built robust skeletons at times when atmospheric carbon dioxide levels were high, but the understanding of this process can be applicable to current rising carbon dioxide levels. Similar work may explain how photosynthetic corals and reefs can exist in times of higher acidity and temperatures as in the past. Plants respond to changes in temperature,
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
, soil quality, and atmospheric gas composition, which can be seen in their fossils. Fossils offer a large array of phenotypes and physiologies that are rare or absent in modern biotas making it possible to assess adaptations that are not found in living species.


Paleoichnology

Paleoichnology is the study of trace fossils, which can display interactions between organisms or other aspects of behavior. Common trace fossils are the burrows of bivalves or
worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...
s in shallow water, feeding traces on the deep
ocean floor The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...
, and the footprints of dinosaurs and other animals in mud and sand beside bodies of water. The description of dinosaur tracks goes back to the early 19th century, but larger discussions about paleoichnology and its uses came with the reidentification of supposed plant fossils as invertebrate trackways in the 1880s to 1920s, where modern analogues were introduced to interpret these trace fossils. Advancements by Adolf Seilacher in the 1960s identified the shortcomings of ichnology: trace fossils were limited in their ability to establish the paleoenvironment, and as they lacked a consistent naming scheme it was difficult to classify and compare trace fossils. Seilacher expanded upon
ichnotaxonomy An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an Artifact (archaeology), artifact. ''Ichnotaxon'' comes from the Ancient Greek (''íchnos'') meaning "track" and English ...
as a way to classify trace fossils according to the behavior that caused them allowing the identification of sedimentary or environmental contexts. From this, ichnotaxonomy differentiates between trace fossils created by tracks, burrows or borings,
excrement Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
, and other types of behaviours, rather than describing the organism that created them. One animal can make many different kinds of traces, and one trace can be made my many different kinds of animals. Footprints made by vertebrates can often be compared more with the organism that could have created them, but this identification is not definitive and can be reinterpreted over time. Different kinds of trace fossils can also be dependent on the type of sediment the organisms were interacting with, with feeding traces on the ocean floor fossilizing differently over different substrates, and trackways of vertebrates being able to be followed across distances. The understanding that trace fossils directly correlate to sediments means that they can be used as indicators of environment types, termed
ichnofacies An ichnofacies is an assemblage of trace fossils that provides an indication of the conditions that their formative organisms inhabited. Concept Trace fossil assemblages are far from random; the range of fossils recorded in association is constra ...
and
paleosols In geoscience, paleosol (''palaeosol'' in Great Britain and Australia) is an ancient soil that formed in the past. The definition of the term in geology and paleontology is slightly different from its use in soil science. In geology and paleon ...
. In rare cases trace fossils can also be preserved alongside body fossils, such as the dinosaur ''
Oryctodromeus ''Oryctodromeus'' (meaning "digging runner") was a genus of small orodromine thescelosaurid dinosaur. Fossils are known from the Late Cretaceous Blackleaf Formation of southwestern Montana and the Wayan Formation of southeastern Idaho, USA, b ...
'' that is the first to show definitive evidence of
burrowing An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of s ...
behavior as its body fossils were found buried within a fossilized burrow. Trace fossils are able to be used as markers of biochronology and biogeography for correlation, and some such as coprolites can be used to understand the diets, diseases, parasites, or climates of the organisms that created them. Some trace fossils show evidence of
gregariousness Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies. Sociality is a survival response to evolutionary pressures. For example, when a mother wasp ...
in animals travelling together in the same direction or congregating at a site, while others can show
pathologies Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...
in the form of uneven
gait Gait is the pattern of Motion (physics), movement of the limb (anatomy), limbs of animals, including Gait (human), humans, during Animal locomotion, locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on s ...
s or pathologic foot impressions. Trackways of footprints can even be used to estimate the size and speed of their creators and their courtship and nesting behaviors.


Taphonomy

Taphonomy is the field of study of the process of fossilization and the processes that occur between burial and discovery. The term taphonomy was introduced in
1940 A calendar from 1940 according to the Gregorian calendar, factoring in the dates of Easter and related holidays, cannot be used again until the year 5280. Events Below, events related to World War II have the "WWII" prefix. January *Janu ...
by
Ivan Yefremov Ivan Antonovich (Antipovich) Yefremov, sometimes Efremov (; 23 April 1908 – 5 October 1972) was a Soviet paleontologist, science-fiction author and social thinker. He founded taphonomy, the study of fossilization patterns. Biography He ...
as a new branch of paleontology, though the consideration of how an organism becomes a fossil predates his work. Taphonomy did not gain prominence as a field until the 1960s when it became important to consider how fossilized deposits relate to their original ecosystems, and the incompleteness of the fossil record became important for evolutionary theories such as punctuated equilibrium. Taphonomic studies of this time involved experimentations to see how the properties of water can transport, sort, or bury bones. It is unlikely that an organism will become a fossil after death, as many factors can damage or destroy both soft and hard tissues before they are buried. The hardest parts of an organism, such as shells or skeletons, are the most likely to survive to be buried and fossilized, though in rare cases soft tissues can be preserved as well. If a dead organism is buried immediately, and particularly in an
anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic ad ...
environment where decay is slowed or stopped, a complete body fossil including both soft and hard tissues may be formed, but even then different chemical or geological processes can alter the fossil, through the mineralization of organic material, or the forming of
concretion A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes a ...
s around them. When not buried immediately, many different taphonomic processes can be involved in the completeness and type of preservation. The transport of organisms from their original position can result in
disarticulation In medical terminology, disarticulation is the separation of two bones at their joint, either traumatically by way of injury or by a surgeon during arthroplasty or amputation. See also * Joint dislocation * Acrotomophilia * Apotemnophilia * Am ...
or the incompleteness of material, and exposure to scavengers or the surrounding environment can result in decay, fragmentation, or abrasion. After burial the rock containing fossils may be flattened geologically or deformed by the
distortion In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...
of
metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...
activity. Plants can commonly be fossilized as layers of
carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...
where all soluble elements of the plant have been removed, and large accumulations of these carbonaceous materials may be transformed into
coal seam Coal mining is the process of extracting coal from the ground or from a mine. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extrac ...
s. Many filters influence the preservation and recovery of fossils, all of which impact the completeness of the fossil record. Common organisms in an environment, that lived around shallow bodies of water with little natural erosion is more likely to be preserved, and after preservation is more likely to be discovered if the rock does not undergo severe metamorphosis, is moved to the surface geologically, and is in a location where it can be exposed to humans. Nearly every paleobiological study incorporates a taphonomic assessment and recognizes biases in the fossil record that can impact their reconstructions.


Cultural significance

Paleontology is one of the most high profile of the sciences. Discoveries, especially on dinosaurs and human evolution, are commonly reported in the
mass media Mass media include the diverse arrays of media that reach a large audience via mass communication. Broadcast media transmit information electronically via media such as films, radio, recorded music, or television. Digital media comprises b ...
, with only
astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the ...
and global health comparable in the level of press attention. Prehistoric life is drawn as inspiration for
toys A toy or plaything is an object that is used primarily to provide entertainment. Simple examples include toy blocks, board games, and dolls. Toys are often designed for use by children, although many are designed specifically for adults and ...
, television and films,
computer games A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...
, and attractions in
tourism Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...
. Environments and organisms from the deep past are some of the most familiar concepts drawn from modern science, such as the dinosaurs ''Tyrannosaurus'', ''Triceratops'' and ''Brontosaurus'', early humans like the neanderthal and ''Homo floresiensis'', extinct megafauna like mammoths and sabre-toothed cats, and invertebrates like trilobites and ammonites. Paleontology academically is not a particularly profitable field of science; the operational budget of the American Museum of Natural History in 2021 was USD, $178 million while the budget of the film ''Jurassic World II'' was $516.1 million. The influence of paleontology in public consciousness may be due to a number of causes such as the mystery, the immense scale of time and some organisms, or the similarities between myths of dragons and
giant In folklore, giants (from Ancient Greek: ''wiktionary:gigas, gigas'', cognate wiktionary:giga-, giga-) are beings of humanoid appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''gia ...
s and their representation in extinct faunas. Paleontologists will draw from public funding and use appeal to gain sponsorships, but the public aspect also overshadows some portions of the field to the benefit of others. There is an overwhelming focus in paleontology on the study of dinosaurs or specific geographical regions, with the most iconic taxa almost exclusively coming from the late 19th and early 20th excavations in North America. The marketing to children of paleontological items can make the field be regarded as "childish" and undermine the utility of the science in popular consciousness. Public perception of paleontology goes back to mythological interpretations of fossils discovery by numerous
indigenous peoples There is no generally accepted definition of Indigenous peoples, although in the 21st century the focus has been on self-identification, cultural difference from other groups in a state, a special relationship with their traditional territ ...
of many continents. Traditional Chinese medicine made use of Pleistocene mammal fossils as "dragon bones" or "dragon teeth", indigenous peoples of Australia and North America made reference to landforms and fossils, and fossils have been interpreted as Nephilim mentioned in the Book of Genesis of European and North American Christianity. Early reconstructions of deep time following the foundation of paleontology saw paleoartistic reconstructions of past ecosystems, including the creation of the Crystal Palace Dinosaurs sculptures and landscaping in the 1850s under the direction of Benjamin Waterhouse Hawkins. Hawkins would also create the first free-standing skeletal mount of a dinosaur in the 1860s: ''Hadrosaurus'' at the Academy of Natural Sciences in Philadelphia. The Bone Wars between American paleontologists Othniel Charles Marsh and Edward Drinker Cope in the late 19th century engaged with the media at the time, and has since been used as a common popular narrative of paleontology through novels, comics, popular books, and even a musical theatre, musical. Following Marsh and Cope, a second American dinosaur rush would occur at the start of the 20th century where new museums and institutions aimed to excavate and display the highest-quality dinosaur fossils, accompanied by paleoart, news media, and exchanges with overseas institutions. This exploitation for popular appeal also intertwined paleontology of the time with
imperialism Imperialism is the maintaining and extending of Power (international relations), power over foreign nations, particularly through expansionism, employing both hard power (military and economic power) and soft power (diplomatic power and cultura ...
, where fossils from Africa, Asia, and South America were excavated and taken by North American and European institutions. Further public engagement of paleontology has taken the form of fictional novels and films focused on paleontology and dinosaurs, beginning with stone-age Europeans in stories of the 1890s, but notably with the publication of ''The Lost World (Doyle novel), The Lost World'' by Arthur Conan Doyle in 1912 in paleontology, 1912. Paleontology would be characterized by many tropes in the following The Lost World (1925 film), film adaptation of the book as well as ''King Kong (1933 film), King Kong'' and ''Fantasia (1940 film), Fantasia'' in the 1920s to 1940s. Popular representations of paleontology would decline coinciding with the Cold War, but resurge in the 1970s with numerous popular works such as ''The Dinosaur Heresies'' by paleontologist Robert Bakker and papers by John Ostrom that would reframe dinosaurs as active animals in a time termed the "dinosaur renaissance". The most significant establishment of paleontology in public would be in the 1990s with the publications of the ''
Jurassic Park ''Jurassic Park'', later referred to as ''Jurassic World'', is an American science fiction media franchise created by Michael Crichton, centered on a disastrous attempt to create a theme park of De-extinction#Cloning, cloned dinosaurs. It bega ...
'' novel by Michael Crichton and the subsequent Steven Spielberg Jurassic Park (film), film, where the story frames warmings about scientific development and genetic technology. Global expansion of paleontology following has been met with the creation of new institutions globally to study and preserve fossils, but the focus since the ''Jurassic Park'' works has been on dinosaurs. New media have risen to paleontological blogging and podcasts and a greater online presence of those in the field. Conjectural forms of paleoart have arisen that engage with new science, and the boundaries between an artist, hobbyist, and professional have blurred. Paleontology has significant amounts of public outreach to drive its engagement and maintain its presence in the public sphere, and this public significance has in turn led to additional resources, recognition, and funding for the science.


Footnotes


References


Further reading

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External links


The Paleontological Society

The Palaeontological Association

The Society of Vertebrate Paleontology
{{Good article Paleontology, Earth sciences Evolutionary biology Fossils, * Historical geology