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The Carboniferous ( ) is a
geologic period 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 geochr ...
and system of the
Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...
that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the
Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...
Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
'' carbō'' ("
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...
") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and
William Phillips William Phillips may refer to: Entertainment * William Phillips (editor) (1907–2002), American editor and co-founder of ''Partisan Review'' * William T. Phillips (1863–1937), American author * William Phillips (director), Canadian film-make ...
in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period.
Tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct t ...
s (four limbed vertebrates), which had originated from
lobe-finned fish Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass includ ...
during the preceding Devonian, became
pentadactylous In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος (''dáktylos'') = "finger". Sometimes the ending "-dactylia" is use ...
in and diversified during the Carboniferous, including early amphibian lineages such as
temnospondyls Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carbo ...
, with the first appearance of amniotes, including
synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ...
s (the group to which modern mammals belong) and reptiles during the late Carboniferous. The period is sometimes called the Age of Amphibians, during which amphibians became dominant land vertebrates and diversified into many forms including lizard-like, snake-like, and crocodile-like. Insects would undergo a major radiation during the late Carboniferous. Vast swaths of forest covered the land, which would eventually be laid down and become the coal beds characteristic of the Carboniferous stratigraphy evident today. The later half of the period experienced
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 ...
s, low sea level, and
mountain building Mountain formation refers to the geological processes that underlie the formation of mountains. These processes are associated with large-scale movements of the Earth's crust (tectonic plates). Folding, faulting, volcanic activity, igneous int ...
as the continents collided to form
Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...
. A minor marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred at the end of the period, caused by climate change.


Etymology and history

The term "Carboniferous" had first been used as an adjective by Irish geologist
Richard Kirwan Richard Kirwan, LL.D, FRS, FRSE MRIA (1 August 1733 – 22 June 1812) was an Irish geologist and chemist. He was one of the last supporters of the theory of phlogiston. Kirwan was active in the fields of chemistry, meteorology, and geol ...
in 1799, and later used in a heading entitled "Coal-measures or Carboniferous Strata" by John Farey Sr. in 1811, becoming an informal term referring to coal-bearing sequences in Britain and elsewhere in Western Europe. Four units were originally ascribed to the Carboniferous, in ascending order, the
Old Red Sandstone The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also exte ...
,
Carboniferous Limestone Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian epoch (geology), Epoch of the Carboniferous period (geology), Period. T ...
, Millstone Grit and the Coal Measures. These four units were placed into a formalised Carboniferous unit by William Conybeare and
William Phillips William Phillips may refer to: Entertainment * William Phillips (editor) (1907–2002), American editor and co-founder of ''Partisan Review'' * William T. Phillips (1863–1937), American author * William Phillips (director), Canadian film-make ...
in 1822, and later into the Carboniferous System by Phillips in 1835. The Old Red Sandstone was later considered Devonian in age. Subsequently, separate stratigraphic schemes were developed in Western Europe, North America, and Russia. The first attempt to build an international timescale for the Carboniferous was during the Eighth International Congress on Carboniferous Stratigraphy and Geology in Moscow in 1975, when all of the modern ICS stages were proposed.


Stratigraphy

The Carboniferous is divided into two subsystems, the lower Mississippian and upper Pennsylvanian, which are sometimes treated as separate geological periods in North American stratigraphy. Stages can be defined globally or regionally. For global stratigraphic correlation, the
International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigr ...
(ICS) ratify global stages based on a
Global Boundary Stratotype Section and Point A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted b ...
(GSSP) from a single
formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...
(a
stratotype A stratotype or type section in geology 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 stan ...
) identifying the lower boundary of the stage. The ICS subdivisions from youngest to oldest are as follows:Cohen, K.M., Finney, S.C., Gibbard, P.L. & Fan, J.-X. (2013; updated
The ICS International Chronostratigraphic Chart
Episodes 36: 199-204.


ICS units

The Mississippian was first proposed by
Alexander Winchell Alexander Winchell (December 31, 1824, in North East, New York – February 19, 1891, in Ann Arbor, Michigan) was a United States geologist who contributed to this field mainly as an educator and a popular lecturer and author. His views on evol ...
, and the Pennsylvanian was proposed by J. J. Stevenson in 1888, and both were proposed as distinct and independent systems by H. S. Williams in 1881. The Tournaisian was named after the Belgian city of Tournai. It was introduced in scientific literature by Belgian geologist
André Hubert Dumont André — sometimes transliterated as Andre — is the French and Portuguese form of the name Andrew, and is now also used in the English-speaking world. It used in France, Quebec, Canada and other French-speaking countries. It is a variation ...
in 1832. The GSSP for the base of the Tournaisian is located at the
La Serre La Serre (; oc, La Sèrra) is a commune in the Aveyron department in southern France. Population The GSSP Golden Spike for the Tournaisian is in La Serre, with the first appearance of the conodont '' Siphonodella sulcata''. In 2006 it wa ...
section in Montagne Noire, southern France. It is defined by the
first appearance datum First appearance datum (FAD) is a term used by geologists and paleontologists to designate the first appearance of a species in the geologic record. FADs are determined by identifying the geologically oldest fossil discovered, to date, of a particu ...
of the conodont '' Siphonodella sulcata'', which was ratified in 1990. However, the GSSP was later shown to have issues, with ''Siphonodella sulcata'' being shown to occur 0.45 m below the proposed boundary. The Viséan Stage was introduced by André Dumont in 1832. Dumont named this stage after the city of
Visé Visé (; nl, Wezet, ; wa, Vizé) is a city and municipality of Wallonia, located on the river Meuse in the province of Liège, Belgium. The municipality consists of the following districts: Argenteau, Cheratte, Lanaye, Lixhe, Richelle ...
in Belgium's
Liège Province Liège (; wa, Lîdje ; nl, Luik ; german: Lüttich ) is the easternmost province of the Wallonia region of Belgium. Liège Province is the only Belgian province that has borders with three countries. It borders (clockwise from the north) the Du ...
. The GSSP for the Visean is located in Bed 83 at the Pengchong section, Guangxi, southern China, which was ratified in 2012. The GSSP for the base of the Viséan is the first appearance datum of
fusulinid The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was dif ...
(an extinct group of
forams Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an ...
) '' Eoparastaffella simplex.'' The Serpukhovian Stage was proposed in 1890 by Russian stratigrapher Sergei Nikitin. It is named after the city of Serpukhov, near
Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...
. The Serpukhovian Stage currently lacks a defined GSSP. The proposed definition for the base of the Serpukhovian is the first appearance of conodont '' Lochriea ziegleri.'' The Bashkirian was named after Bashkiria, the then Russian name of the republic of
Bashkortostan The Republic of Bashkortostan or Bashkortostan ( ba, Башҡортостан Республикаһы, Bashqortostan Respublikahy; russian: Республика Башкортостан, Respublika Bashkortostan),; russian: Респу́блик ...
in the southern
Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
of Russia. The stage was introduced by Russian stratigrapher Sofia Semikhatova in 1934. The GSSP for the base of the Bashkirian is located at Arrow Canyon in Nevada, USA, which was ratified in 1996. The GSSP for the base of the Bashkirian is defined by the first appearance of the conodont ''Declinognathodus noduliferus''.'''' The Moscovian is named after Moscow, Russia, and was first introduced by Sergei Nikitin in 1890. The Moscovian currently lacks a defined GSSP. The Kasimovian is named after the Russian city of
Kasimov Kasimov (russian: Каси́мов; tt-Cyrl, Касыйм;, Ханкирмән,Ханкирмән, Хан-Кермень, means "Khan's fortress" historically Gorodets Meshchyorsky, Novy Nizovoy) is a town in Ryazan Oblast, Russia, located on the ...
, and originally included as part of Nikitin's original 1890 definition of the Moscovian. It was first recognised as a distinct unit by A.P. Ivanov in 1926, who named it the "'' Tiguliferina''" Horizon after a kind of
brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...
. The Kasimovian currently lacks a defined GSSP. The Gzhelian is named after the Russian village of
Gzhel Gzhel is a Russian style of blue and white ceramics which takes its name from the village of Gzhel and surrounding area, where it has been produced since 1802. Overview About thirty villages located southeast of Moscow produce pottery and shi ...
(russian: Гжель), nearby Ramenskoye, not far from Moscow. The name and type locality were defined by Sergei Nikitin in 1890. The base of the Gzhelian currently lacks a defined GSSP. The GSSP for the base of the Permian is located in the Aidaralash River valley near
Aqtöbe Aktobe ( kz, Ақтөбе, Aqtöbe; russian: Актобе, Aktobe) is a city on the Ilek River in Kazakhstan. It is the administrative center of Aktobe Region. In 2020, it had a population of 500,757 people. Aktobe is located in the west of K ...
, Kazakhstan, which was ratified in 1996. The beginning of the stage is defined by the first appearance of the conodont '' Streptognathodus postfusus.''


Regional stratigraphy


North America

In North American stratigraphy, the Mississippian is divided, in ascending order, into the Kinderhookian, Osagean, Meramecian and Chesterian series, while the Pennsylvanian is divided into the Morrowan, Atokan, Desmoinesian, Missourian and Virgilian series. The Kinderhookian is named after the village of Kinderhook, Pike County, Illinois. It corresponds to the lower part of the Tournasian. The Osagean is named after the
Osage River The Osage River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed May 31, 2011 tributary of the Missouri River in central Missouri in the United States. The eighth-largest river ...
in St. Clair County, Missouri. It corresponds to the upper part of the Tournaisian and the lower part of the Viséan. The Meramecian is named after the Meramec Highlands Quarry, located the near the
Meramec River The Meramec River (), sometimes spelled Maramec River, is one of the longest free-flowing waterways in the U.S. state of Missouri, draining Blanc, Caldwell, and Hawk. "Location" while wandering Blanc, Caldwell, and Hawk. "Executive Summary" fr ...
, southwest of
St. Louis St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the bi-state metropolitan area, which e ...
, Missouri. It corresponds to the mid Viséan. The Chesterian is named after the
Chester Group Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Local ...
, a sequence of rocks named after the town of
Chester, Illinois Chester is a city in and the county seat of Randolph County, Illinois, United States, on a bluff above the Mississippi River. The population was 6,814 at the 2020 census. It lies south of St. Louis, Missouri. History Founding Samuel Smith is ...
. It corresponds to the upper Viséan and all of the Serpukhovian. The Morrowan is named after the Morrow Formation located in NW Arkansas, it corresponds to the lower Bashkirian. The Atokan was originally a formation named after the town of Atoka in southwestern Oklahoma. It corresponds to the upper Bashkirian and lower Moscovian The Desmoinesian is named after the Des Moines Formation found near the
Des Moines River The Des Moines River () is a tributary of the Mississippi River in the upper Midwestern United States that is approximately long from its farther headwaters.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe Na ...
in central Iowa. It corresponds to the middle and upper Moscovian and lower Kasimovian. The Missourian was named at the same time as the Desmoinesian. It corresponds to the middle and upper Kasimovian. The Virgilian is named after the town of Virgil, Kansas, it corresponds to the Gzhelian.


Europe

The European Carboniferous is divided into the lower
Dinantian Dinantian is the name of a series or epoch from the Lower Carboniferous system in Europe. It can stand for a series of rocks in Europe or the time span in which they were deposited. The Dinantian is equal to the lower part of the Mississippian s ...
and upper Silesian, the former being named for the Belgian city of Dinant, and the latter for the
Silesia Silesia (, also , ) is a historical region of Central Europe that lies mostly within Poland, with small parts in the Czech Republic and Germany. Its area is approximately , and the population is estimated at around 8,000,000. Silesia is split ...
region of Central Europe. The boundary between the two subdivisions is older than the Mississippian-Pennsylvanian boundary, lying within the lower Serpukhovian. The boundary has traditionally been marked by the first appearance of the ammonoid '' Cravenoceras leion.'' In Europe, the Dinantian is primarily marine, the so-called "Carboniferous Limestone", while the Silesian primarily known for its coal measures. The Dinantian is divided up into two stages, the Tournaisian and Viséan. The Tournaisian is the same length as the ICS stage, but the Viséan is longer, extending into the lower Serpukhovian. The Silesian is divided into three stages, in ascending order, the
Namurian The Namurian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 326 and 313 Ma (million years ago). It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Namurian ...
, Westphalian, Stephanian. The Autunian, which corresponds to the middle and upper Gzhelian, is considered a part of the overlying
Rotliegend The Rotliegend, Rotliegend Group or Rotliegendes (german: the underlying red) is a lithostratigraphic unit (a sequence of rock strata) of latest Carboniferous to Guadalupian (middle Permian) age that is found in the subsurface of large areas in wes ...
. The Namurian is named after the city of Namur in Belgium. It corresponds to the middle and upper Serpukhovian and the lower Bashkirian. The Westphalian is named after the region of
Westphalia Westphalia (; german: Westfalen ; nds, Westfalen ) is a region of northwestern Germany and one of the three historic parts of the state of North Rhine-Westphalia. It has an area of and 7.9 million inhabitants. The territory of the regio ...
in Germany it corresponds to the upper Bashkirian and all but the uppermost Moscovian. The Stephanian is named after the city of Saint-Étienne in eastern France. It corresponds to the uppermost Moscovian, the Kasimovian, and the lower Gzhelian.


Palaeogeography

A global drop in
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 standardise ...
at the end of the Devonian reversed early in the Carboniferous; this created the widespread
inland seas An inland sea (also known as an epeiric sea or an epicontinental sea) is a continental body of water which is very large and is either completely surrounded by dry land or connected to an ocean by a river, strait, or "arm of the sea". An inland se ...
and the
carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate ...
deposition of the Mississippian. There was also a drop in south polar temperatures; southern Gondwanaland was
glaciated A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...
for much of the period, though it is uncertain if the ice sheets were a holdover from the Devonian or not. These conditions apparently had little effect in the deep tropics, where lush swamps, later to become coal, flourished to within 30 degrees of the northernmost
glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...
s. Mid-Carboniferous, a drop in sea level precipitated a major marine extinction, one that hit
crinoids Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
and
ammonites Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttl ...
especially hard. This sea level drop and the associated
unconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...
in North America separate the Mississippian Subperiod from the Pennsylvanian Subperiod. This happened about 323 million years ago, at the onset of the Permo-Carboniferous Glaciation. The Carboniferous was a time of active
mountain-building Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted t ...
as the
supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leav ...
Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...
came together. The southern
continent A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions In geography, regions, otherwise referred to as zones, lands or territories, are areas t ...
s remained tied together in the supercontinent Gondwana, which collided with North America–Europe (
Laurussia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...
) along the present line of eastern North America. This continental collision resulted in the
Hercynian orogeny The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan'', comes f ...
in Europe, and the
Alleghenian orogeny The Alleghanian orogeny or Appalachian orogeny is one of the geological mountain-forming events that formed the Appalachian Mountains and Allegheny Mountains. The term and spelling Alleghany orogeny was originally proposed by H.P. Woodward in 195 ...
in North America; it also extended the newly uplifted
Appalachians The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
southwestward as the
Ouachita Mountains The Ouachita Mountains (), simply referred to as the Ouachitas, are a mountain range in western Arkansas and southeastern Oklahoma. They are formed by a thick succession of highly deformed Paleozoic strata constituting the Ouachita Fold and Thru ...
. In the same time frame, much of present eastern
Eurasian plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
welded itself to Europe along the line of the
Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
. Most of the
Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...
supercontinent of Pangea was now assembled, although North China (which would collide in the Latest Carboniferous), and South China continents were still separated from Laurasia. The Late Carboniferous Pangaea was shaped like an "O". There were two major oceans in the Carboniferous:
Panthalassa Panthalassa, also known as the Panthalassic Ocean or Panthalassan Ocean (from Greek "all" and "sea"), was the superocean that surrounded the supercontinent Pangaea, the latest in a series of supercontinents in the history of Earth. During th ...
and
Paleo-Tethys The Paleo-Tethys or Palaeo-Tethys Ocean was an ocean located along the northern margin of the paleocontinent Gondwana that started to open during the Middle Cambrian, grew throughout the Paleozoic, and finally closed during the Late Triassic; ex ...
, which was inside the "O" in the Carboniferous Pangaea. Other minor oceans were shrinking and eventually closed: the
Rheic Ocean The Rheic Ocean was an ocean which separated two major palaeocontinents, Gondwana and Laurussia (Laurentia- Baltica-Avalonia). One of the principal oceans of the Palaeozoic, its sutures today stretch from Mexico to Turkey and its closure result ...
(closed by the assembly of South and North America), the small, shallow
Ural Ocean The Ural Ocean (also called the Uralic Ocean) was a small, ancient ocean that was situated between Siberia and Baltica. The ocean formed in the Late Ordovician epoch, when large islands from Siberia collided with Baltica, which was then part of ...
(which was closed by the collision of
Baltica Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains. The thick core of Baltica, the East European Craton, ...
and Siberia continents, creating the
Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
), and the
Proto-Tethys Ocean The Proto-Tethys or Theic Ocean was an ancient ocean that existed from the latest Ediacaran to the Carboniferous (550–330 Ma). History of concept The name "Proto-Tethys" has been used inconsistently for several concepts for a supposed predecess ...
(closed by North China collision with
Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...
/
Kazakhstania Kazakhstania ( kk, Qazaqstaniya), the Kazakh terranes, or the Kazakhstan Block, is a geological region in Central Asia which consists of the area roughly centered on Lake Balkhash, north and east of the Aral Sea, south of the Siberian craton and ...
).


Climate

Average global temperatures in the Early Carboniferous Period were high: approximately 20 °C (68 °F). However, cooling during the Middle Carboniferous reduced average global temperatures to about 12 °C (54 °F). Atmospheric
carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
levels fell during the Carboniferous Period from roughly 8 times the current level in the beginning, to a level similar to today's at the end. The Carboniferous is considered part of the Late Palaeozoic Ice Age, which began in the latest Devonian with the formation of small glaciers in Gondwana. During the Tournaisian the climate warmed, before cooling, there was another warm interval during the Viséan, but cooling began again during the early Serpukhovian. At the beginning of the Pennsylvanian around 323 million years ago, glaciers began to form around the
South Pole The South Pole, also known as the Geographic South Pole, Terrestrial South Pole or 90th Parallel South, is one of the two points where Earth's axis of rotation intersects its surface. It is the southernmost point on Earth and lies antipod ...
, which would grow to cover a vast area of Gondwana. This area extended from the southern reaches of the Amazon basin and covered large areas of
southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...
, as well as most of Australia and Antarctica.
Cyclothems In geology, cyclothems are alternating stratigraphy, stratigraphic sequences of Marine (ocean), marine and non-marine sediments, sometimes interbedded with coal seams. Historically, the term was defined by the European coal geologists who worked ...
, which began around 313 million years ago, and continue into the following Permian indicate that the size of the glaciers were controlled by
Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...
akin to recent
ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
s, with
glacial period 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 betwe ...
s and interglacials. Deep ocean temperatures during this time were cold due to the influx of cold bottom waters generated by seasonal melting of the ice cap. The cooling and drying of the climate led to the Carboniferous Rainforest Collapse (CRC) during the late Carboniferous. Tropical rainforests fragmented and then were eventually devastated by climate change.


Rocks and coal

Carboniferous rocks in Europe and eastern North America largely consist of a repeated sequence of
limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
,
sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...
, shale and
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...
beds. In North America, the early Carboniferous is largely marine limestone, which accounts for the division of the Carboniferous into two periods in North American schemes. The Carboniferous coal beds provided much of the fuel for power generation during the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
and are still of great economic importance. The large coal deposits of the Carboniferous may owe their existence primarily to two factors. The first of these is the appearance of
wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...
tissue and bark-bearing trees. The
evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
of the wood fiber lignin and the bark-sealing, waxy substance
suberin Suberin, cutin and lignins are complex, higher plant epidermis and periderm cell-wall macromolecules, forming a protective barrier. Suberin, a complex polyester biopolymer, is lipophilic, and composed of long chain fatty acids called suberin aci ...
variously opposed decay organisms so effectively that dead materials accumulated long enough to fossilise on a large scale. The second factor was the lower sea levels that occurred during the Carboniferous as compared to the preceding Devonian Period. This fostered the development of extensive lowland swamps and
forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
s in North America and Europe. Based on a genetic analysis of mushroom fungi, it was proposed that large quantities of
wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...
were buried during this period because animals and decomposing
bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
and fungi had not yet
evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
enzymes that could effectively digest the resistant phenolic lignin polymers and waxy suberin polymers. They suggest that fungi that could break those substances down effectively only became dominant towards the end of the period, making subsequent coal formation much rarer. The delayed fungal evolution hypothesis is controversial, however, and has been challenged by other researchers, who conclude that a combination of vast depositional systems present on the continents during the formation of Pangaea and widespread humid, tropical conditions were responsible for the high rate of coal formation. The Carboniferous trees made extensive use of lignin. They had bark to wood ratios of 8 to 1, and even as high as 20 to 1. This compares to modern values less than 1 to 4. This bark, which must have been used as support as well as protection, probably had 38% to 58% lignin. Lignin is insoluble, too large to pass through cell walls, too heterogeneous for specific enzymes, and toxic, so that few organisms other than
Basidiomycetes Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Ba ...
fungi can degrade it. To oxidize it requires an atmosphere of greater than 5% oxygen, or compounds such as peroxides. It can linger in soil for thousands of years and its toxic breakdown products inhibit decay of other substances. One possible reason for its high percentages in plants at that time was to provide protection from insects in a world containing very effective insect herbivores (but nothing remotely as effective as modern plant eating insects) and probably many fewer protective toxins produced naturally by plants than exist today. As a result, undegraded carbon built up, resulting in the extensive burial of biologically fixed
carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon mak ...
, leading to an increase in
oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...
levels in the atmosphere; estimates place the peak oxygen content as high as 35%, as compared to 21% today. This oxygen level may have increased
wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...
activity. It also may have promoted gigantism of
insect Insects (from Latin ') are pancrustacean 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 ...
s and amphibians, creatures whose size is today limited by their
respiratory The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gre ...
systems' ability to transport and distribute oxygen at lower atmospheric concentrations. In eastern North America, marine beds are more common in the older part of the period than the later part and are almost entirely absent by the late Carboniferous. More diverse geology existed elsewhere, of course. Marine life is especially rich in
crinoids Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
and other echinoderms.
Brachiopods Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, wh ...
were abundant.
Trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
s became quite uncommon. On land, large and diverse
plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...
populations existed. Land
vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
included large amphibians.


Life


Plants

Early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * ...
land plants, some of which were preserved in
coal ball A coal ball is a type of concretion, varying in shape from an imperfect sphere to a flat-lying, irregular slab. Coal balls were formed in Carboniferous Period swamps and mires, when peat was prevented from being turned into coal by the high am ...
s, were very similar to those of the preceding Late Devonian, but new groups also appeared at this time. The main Early Carboniferous plants were the
Equisetales Equisetales is an order of subclass Equisetidae with only one living family, Equisetaceae Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which ...
(horse-tails),
Sphenophyllales Sphenophyllales is an extinct order of articulate land plants and a sister group to the present-day Equisetales (horsetails). They are fossils dating from the Devonian to the Triassic. They were common during the Late Pennsylvanian to Early ...
(scrambling plants),
Lycopodiales The Lycopodiaceae (class Lycopodiopsida, order Lycopodiales) are an old family of vascular plants, including all of the core clubmosses and firmosses, comprising 16 accepted genera and about 400 known species. This family originated about 380 mil ...
(club mosses),
Lepidodendrales Lepidodendrales (from the Greek for "scale tree") were primitive, vascular, heterosporous, arborescent (tree-like) plants related to present day lycopsids. Members of Lepidodendrales are the best understood of the fossil lycopsids due to the vas ...
(scale trees),
Filicales The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four class (biology), subclasses of ferns, and the largest of these, being the largest group of living ferns, including some 11,000 species worldwide ...
(ferns),
Medullosales The Medullosales is an extinct order of pteridospermous seed plants characterised by large ovules with circular cross-section and a vascularised nucellus, complex pollen-organs, stems and rachides with a dissected stele, and frond-like leaves. ...
(informally included in the " seed ferns", an assemblage of a number of early
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν ...
groups) and the
Cordaitales Cordaitales are an extinct order of gymnosperms, known from the early Carboniferous to the late Permian. Many Cordaitales had elongated strap-like leaves, resembling some modern-day conifers of the Araucariaceae and Podocarpaceae. They had cone ...
. These continued to dominate throughout the period, but during
late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...
, several other groups,
Cycadophyta Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male o ...
(cycads), the Callistophytales (another group of "seed ferns"), and the
Voltziales Voltziales is an extinct order of conifers. The group contains the ancestral lineages from which all modern conifer groups emerged. The earliest Voltzialean conifers appear in the Late Carboniferous ( Pennsylvanian). Modern conifer lineages em ...
(related to and sometimes included under the conifers), appeared. The Carboniferous lycophytes of the order Lepidodendrales, which are cousins (but not ancestors) of the tiny club-moss of today, were huge trees with trunks 30 meters high and up to 1.5 meters in diameter. These included ''
Lepidodendron ''Lepidodendron'' is an extinct genus of primitive vascular plants belonging to the family Lepidodendraceae, part of a group of Lycopodiopsida known as scale trees or arborescent lycophytes, related to quillworts and lycopsids (club mosses). Th ...
'' (with its cone called Lepidostrobus), '' Anabathra'', '' Lepidophloios'' and ''
Sigillaria ''Sigillaria'' is a genus of extinct, spore-bearing, arborescent (tree-like) plants. It was a lycopodiophyte, and is related to the lycopsids, or club-mosses, but even more closely to quillworts, as was its associate ''Lepidodendron''. Fossil ...
''. The roots of several of these forms are known as
Stigmaria ''Stigmaria'' is a form taxon for common fossils found in Carboniferous rocks. They represent the underground rooting structures of coal forest lycopsid trees such as '' Sigillaria'' and '' Lepidodendron''. These swamp forest trees grew to ...
. Unlike present-day trees, their
secondary growth In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of ...
took place in the
cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...
, which also provided stability, instead of the
xylem Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
. The Cladoxylopsids were large trees, that were ancestors of ferns, first arising in the Carboniferous. The fronds of some Carboniferous ferns are almost identical with those of living species. Probably many species were
epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...
. Fossil ferns and "seed ferns" include ''
Pecopteris ''Pecopteris'' is a very common form genus of leaves. Most ''Pecopteris'' leaves and fronds are associated with the marattialean tree fern ''Psaronius''. However, ''Pecopteris''-type foliage also is borne on several filicalean ferns, and at le ...
'', ''
Cyclopteris ''Cyclopteris'' is an extinct genus of seed ferns in the extinct family † Cyclopteridaceae. Species are from the Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end ...
'', '' Neuropteris'', ''
Alethopteris ''Alethopteris'' is a prehistoric plant genus of fossil Pteridospermatophyta (seed ferns) that developed in the Carboniferous period (around ). It is in the family Alethopteridaceae. The genus Alethopteris is among the seed ferns ( Pteridosp ...
'', and ''
Sphenopteris ''Sphenopteris'' is a genus of seed ferns containing the foliage of various extinct plants, ranging from the Devonian to Late Cretaceous. One species, ''S. höninghausi'', was transferred to the genus '' Crossotheca'' in 1911. Biology The fro ...
''; '' Megaphyton'' and '' Caulopteris'' were tree ferns. The Equisetales included the common giant form ''
Calamites ''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights o ...
'', with a trunk diameter of 30 to and a height of up to . ''
Sphenophyllum ''Sphenophyllum'' is a genus in the order Sphenophyllales Sphenophyllales is an extinct order of articulate land plants and a sister group to the present-day Equisetales (horsetails). They are fossils dating from the Devonian to the Triassi ...
'' was a slender climbing plant with whorls of leaves, which was probably related both to the calamites and the lycopods. ''
Cordaites ''Cordaites'' is an important genus of extinct gymnosperms which grew on wet ground similar to the Everglades in Florida. Brackish water mussels and crustacea are found frequently between the roots of these trees. The fossils are found in rock ...
'', a tall plant (6 to over 30 meters) with strap-like leaves, was related to the cycads and conifers; the catkin-like reproductive organs, which bore ovules/seeds, is called ''
Cardiocarpus ''Cordaites'' is an important genus of extinct gymnosperms which grew on wet ground similar to the Everglades in Florida. Brackish water mussels and crustacea are found frequently between the roots of these trees. The fossils are found in rock ...
''. These plants were thought to live in swamps. True coniferous trees (''
Walchia ''Walchia'' is a fossil conifer, Cupressaceae, cypress-like genus found in upper Pennsylvanian (geology), Pennsylvanian (Carboniferous) and lower Permian (about 310-290 Mya (unit), Mya) rocks of Europe and North America. A forest of In situ, in-s ...
'', of the order Voltziales) appear later in the Carboniferous, and preferred higher drier ground.


Marine invertebrates

In the oceans the
marine invertebrate Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some hav ...
groups are the
Foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly ...
,
corals Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secr ...
,
Bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a ...
,
Ostracoda Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typical ...
,
brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...
s,
ammonoids Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
, hederelloids,
microconchids The order Microconchida is a group of small, spirally-coiled, encrusting fossil "worm" tubes from the class Tentaculita found from the Upper Ordovician to the Middle Jurassic (Bathonian) around the world. They have lamellar calcitic shells, u ...
and
echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the s ...
s (especially
crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
s). The diversity of brachiopods and fusilinid foraminiferans, surged beginning in the Visean, continuing through the end of the Carboniferous, although cephalopod and nektonic conodont diversity declined. For the first time foraminifera take a prominent part in the marine faunas. The large spindle-shaped genus
Fusulina The Fusulinidae is a family of fusulinacean foraminifera from the upper Carboniferous (Lower Pennsylvanian, Morrowan) to the Upper Permian (Guadalupian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was ...
and its relatives were abundant in what is now Russia, China, Japan, North America; other important genera include ''Valvulina'', ''Endothyra'', ''Archaediscus'', and ''Saccammina'' (the latter common in Britain and Belgium). Some Carboniferous genera are still extant. The first true
priapulid Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' 'Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertility ...
s appeared during this period. The microscopic shells of
radiolaria The Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The el ...
ns are found in
chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a ...
s of this age in the Culm of
Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devo ...
and
Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
, and in Russia, Germany and elsewhere. Sponges are known from
spicule Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: *Spicule (sponge), small skeletal elements of sea sponges *Spicule (nematode), reproductive structures found in male nematodes ( ...
s and anchor ropes, and include various forms such as the Calcispongea ''Cotyliscus'' and ''Girtycoelia'', the
demosponge Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide (World Porifera Database). They are sponges with a soft body that covers a har ...
''Chaetetes'', and the genus of unusual colonial glass sponges '' Titusvillia''. Both
reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock o ...
-building and solitary corals diversify and flourish; these include both
rugose Rugose means "wrinkled". It may refer to: * Rugosa, an extinct order of coral, whose rugose shape earned it the name * Rugose, adjectival form of rugae Species with "rugose" in their names * ''Idiosoma nigrum'', more commonly, a black rugose trap ...
(for example, '' Caninia'', ''Corwenia'', ''Neozaphrentis''), heterocorals, and
tabulate Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to a ...
(for example, ''Chladochonus'', ''Michelinia'') forms. Conularids were well represented by ''Conularia''
Bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a ...
are abundant in some regions; the fenestellids including ''Fenestella'', ''Polypora'', and '' Archimedes'', so named because it is in the shape of an Archimedean screw.
Brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...
s are also abundant; they include productids, some of which reached very large for brachiopods size and had very thick shells (for example, the -wide ''
Gigantoproductus ''Gigantoproductus'' is a genus of extinct brachiopods in the order Productida and the family Monticuliferidae. The species were the largest of the carboniferous brachiopods, with the largest known species reaching in shell width. Such huge ...
''), while others like ''
Chonetes ''Chonetes'' is an extinct genus of brachiopods. It ranged from the Late Ordovician to the Middle Jurassic. Species The following species of ''Chonetes'' have been described: * ''C. (Paeckelmannia)'' * ''C. baragwanathi'' * ''C. billingsi' ...
'' were more conservative in form. Athyridids, spiriferids, rhynchonellids, and terebratulids are also very common. Inarticulate forms include '' Discina'' and '' Crania''. Some species and genera had a very wide distribution with only minor variations. Annelids such as ''Serpulites'' are common fossils in some horizons. Among the mollusca, the bivalves continue to increase in numbers and importance. Typical genera include '' Aviculopecten'', '' Posidonomya'', ''
Nucula ''Nucula'' is a genus of very small saltwater clams. They are part of the family Nuculidae. Fossil records This genus is very ancient. Fossils are known from the Arenig to the Quaternary (age range: from 478.6 to 0.0 million years ago). Fossils ...
'', '' Carbonicola'', ''Edmondia'', and ''Modiola''. Gastropods are also numerous, including the genera ''Murchisonia'', ''
Euomphalus ''Euomphalus'' is a genus of fossil marine gastropods known to have lived from the Silurian to the Middle Permian.J.B.Knight,et al 1960. Treatise on Invertebrate Paleontology, Part I, Mollusca 1, ch on systematic descriptions. Geol Soc of Amer ...
'', ''Naticopsis''.
Nautiloid Nautiloids are a group of marine cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and '' Allonautilus''. Fossil nautiloids are diverse and speciose, with over 2,500 recorded specie ...
cephalopods are represented by tightly coiled nautilids, with straight-shelled and curved-shelled forms becoming increasingly rare.
Goniatite Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago (around Eifelian stage). Goniatites (goniatitids) survi ...
ammonoids Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
such as Aenigmatoceras are common.
Trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
s are rarer than in previous periods, on a steady trend towards extinction, represented only by the proetid group.
Ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typi ...
a, a class of
crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s, were abundant as representatives of the meiobenthos; genera included ''Amphissites'', ''Bairdia'', ''Beyrichiopsis'', ''Cavellina'', ''Coryellina'', ''Cribroconcha'', ''Hollinella'', ''Kirkbya'', ''Knoxiella'', and ''Libumella''. Amongst the
echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the s ...
s, the
crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
s were the most numerous. Dense submarine thickets of long-stemmed crinoids appear to have flourished in shallow seas, and their remains were consolidated into thick beds of rock. Prominent genera include ''Cyathocrinus'', ''Woodocrinus'', and ''Actinocrinus''. Echinoids such as '' Archaeocidaris'' and ''Palaeechinus'' were also present. The
blastoid Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississ ...
s, which included the Pentreinitidae and Codasteridae and superficially resembled crinoids in the possession of long stalks attached to the seabed, attain their maximum development at this time. File:Aviculopecten subcardiformis01.JPG, ''Aviculopecten subcardiformis''; a bivalve from the
Logan Formation The Logan Formation is the name given to a Lower Carboniferous (early Osagean) siltstone, sandstone and conglomeratic unit exposed in east-central Ohio and parts of western West Virginia, USA. Stratigraphy and paleoenvironment The Logan Format ...
(Lower Carboniferous) of
Wooster, Ohio Wooster ( ) is a city in the U.S. state of Ohio and the county seat of Wayne County. Located in northeastern Ohio, the city lies approximately south-southwest of Cleveland, southwest of Akron and west of Canton. The population was 27,232 at ...
(external mold) File:LoganFauna011312.jpg, Bivalves (''Aviculopecten'') and brachiopods (''Syringothyris'') in the Logan Formation (Lower Carboniferous) in Wooster, Ohio File:Syringothyris01.JPG, ''Syringothyris'' sp.; a spiriferid
brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...
from the Logan Formation (Lower Carboniferous) of Wooster, Ohio (internal mold) File:Palaeophycus01.JPG, ''Palaeophycus'' ichnosp.; a
trace fossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...
from the Logan Formation (Lower Carboniferous) of Wooster, Ohio File:PlatyceratidMississippian.JPG,
Crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
calyx from the Lower Carboniferous of Ohio with a conical platyceratid gastropod (''Palaeocapulus acutirostre'') attached File:Conulariid03.jpg, Conulariid from the Lower Carboniferous of Indiana File:Syringoporid.jpg, Tabulate coral (a syringoporid); Boone Limestone (Lower Carboniferous) near Hiwasse, Arkansas


Freshwater and lagoonal invertebrates

Freshwater Carboniferous invertebrates include various bivalve molluscs that lived in brackish or fresh water, such as ''Anthraconaia'', '' Naiadites'', and '' Carbonicola''; diverse
crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s such as '' Candona'', ''
Carbonita Carbonita is a municipality in the northeast of the Brazilian state of Minas Gerais. the population was 9,414 in a total area of 1,454 km2. The elevation of the town center is 751 meters. It is part of the IBGE statistical meso-region of Jeq ...
'', ''
Darwinula ''Darwinula'' is a genus of ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several ...
'', '' Estheria'', ''Acanthocaris'', ''Dithyrocaris'', and ''Anthrapalaemon''. The
eurypterid Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is l ...
s were also diverse, and are represented by such genera as ''
Adelophthalmus ''Adelophthalmus'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Adelophthalmus'' have been discovered in deposits ranging in age from the Early Devonian to the Early Permian, which makes it the longest lived of ...
'', ''
Megarachne ''Megarachne'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Megarachne'' have been discovered in deposits of Late Carboniferous age, from the Gzhelian stage, in San Luis, Argentina. The fossils of the single and ...
'' (originally misinterpreted as a giant spider, hence its name) and the specialised very large ''
Hibbertopterus ''Hibbertopterus'' is a genus of eurypterid, a group of extinct aquatic arthropods. Fossils of ''Hibbertopterus'' have been discovered in deposits ranging from the Devonian period in Belgium, Scotland and the United States to the Carboniferous ...
''. Many of these were amphibious. Frequently a temporary return of marine conditions resulted in marine or brackish water genera such as '' Lingula'', ''Orbiculoidea'', and '' Productus'' being found in the thin beds known as marine bands.


Terrestrial invertebrates

Fossil remains of air-breathing
insect Insects (from Latin ') are pancrustacean 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 ...
s,
myriapod Myriapods () are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial. The fossil record of myriapods reaches back into the late Silurian, ...
s and
arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegar ...
s are known from the late Carboniferous, but so far not from the early Carboniferous. Their diversity when they do appear, however, shows that these arthropods were both well-developed and numerous. Their large size can be attributed to the moistness of the environment (mostly swampy fern forests) and the fact that the oxygen concentration in the Earth's atmosphere in the Carboniferous was much higher than today. This required less effort for respiration and allowed arthropods to grow larger with the up to millipede-like ''
Arthropleura ''Arthropleura'' () is a genus of extinct millipede arthropods that lived in what is now North America and Europe around 345 to 290 million years ago, from the Viséan stage of the lower Carboniferous Period to the Sakmarian stage of the lower ...
'' being the largest-known land invertebrate of all time. Among the insect groups are the huge predatory
Protodonata Meganisoptera is an extinct order of very large to gigantic insects, informally called griffinflies. The order was formerly named Protodonata, the "proto-Odonata", for their similar appearance and supposed relation to modern Odonata (damselflies ...
(griffinflies), among which was ''
Meganeura ''Meganeura'' is a genus of extinct insects from the Late Carboniferous (approximately 300 million years ago). They resembled and are related to the present-day dragonflies and damselflies, and were predatory, with their diet mainly consisting o ...
'', a giant dragonfly-like insect and with a wingspan of ca. —the largest flying insect ever to roam the planet. Further groups are the Syntonopterodea (relatives of present-day
mayflies Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the order ...
), the abundant and often large sap-sucking
Palaeodictyopteroidea The Palaeodictyopteroidea or Paleodictyopterida are an extinct superorder of Palaeozoic beaked insects, characterised by unique mouthparts consisting of 5 stylets. They represent the first important terrestrial herbivores, and the first major gr ...
, the diverse herbivorous
Protorthoptera The Protorthoptera are an extinct order of Palaeozoic insects, and represent a wastebasket taxon and paraphyletic assemblage of basal neoptera. They appear during the Middle Carboniferous (late Serpukhovian or early Bashkirian), making them a ...
, and numerous basal
Dictyoptera Dictyoptera (from Greek δίκτυον ''diktyon'' "net" and πτερόν ''pteron'' "wing") is an insect superorder that includes two extant orders of polyneopterous insects: the order Blattodea (termites and cockroaches together) and the o ...
(ancestors of
cockroach Cockroaches (or roaches) are a Paraphyly, paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are we ...
es). Many insects have been obtained from the coalfields of Saarbrücken and
Commentry Commentry (; Auvergnat: ''Comentriac'') is a commune in the department of Allier in central France. It lies southwest of Moulins in the valley of the Œil. It is within 8 km of one of the geographic centres of France. The film actress ...
, and from the hollow trunks of fossil trees in Nova Scotia. Some British coalfields have yielded good specimens: ''Archaeoptilus'', from the Derbyshire coalfield, had a large wing with preserved part, and some specimens ('' Brodia'') still exhibit traces of brilliant wing colors. In the Nova Scotian tree trunks land snails (''Archaeozonites'', ''Dendropupa'') have been found. File:Meganeura monyi au Museum de Toulouse.jpg, The late Carboniferous giant dragonfly-like insect ''
Meganeura ''Meganeura'' is a genus of extinct insects from the Late Carboniferous (approximately 300 million years ago). They resembled and are related to the present-day dragonflies and damselflies, and were predatory, with their diet mainly consisting o ...
'' grew to wingspans of . File:20210116 Pulmonoscorpius kirktonensis.png, The gigantic '' Pulmonoscorpius'' from the early Carboniferous reached a length of up to . File:20211224 Arthropleura armata diagrammatic reconstruction.png, ''Arthropleura'' was a giant millipede that fed on the Carboniferous plants. File:Mazothairos1.jpg, ''
Mazothairos ''Mazothairos'' (from Mazo, derived from its location of Mazon Creek and θαιρός, ''thairos'', meaning 'hinge' in Greek) is an extinct genus of very large insect from the Carboniferous period. It was a member of the order Palaeodictyoptera ...
'' was a large
palaeodictyoptera The Palaeodictyoptera are an extinct order of medium-sized to very large, primitive Palaeozoic paleopterous insects. They are informative about the evolution of wings in insects. Overview They were characterized by beak-like mouthparts, used ...
n insect from
Mazon Creek The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concreti ...
. File:Helenodora inopinata.jpg, ''Helenodora inopinata'', a
Stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
onychophora Onychophora (from grc, ονυχής, , "claws"; and , , "to carry"), commonly known as velvet worms (due to their velvety texture and somewhat wormlike appearance) or more ambiguously as peripatus (after the first described genus, '' Peripatus ...
n known from
Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...
File:Blattoidae - Fossil.JPG, A Blattoid
Cockroach Cockroaches (or roaches) are a Paraphyly, paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are we ...
found in Carboniferous rocks of France


Fish

Many fish inhabited the Carboniferous seas; predominantly
Elasmobranch Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of g ...
s (sharks and their relatives). These included some, like '' Psammodus'', with crushing pavement-like teeth adapted for grinding the shells of brachiopods, crustaceans, and other marine organisms. Other sharks had piercing teeth, such as the Symmoriida; some, the
petalodont Petalodontiformes ("thin-plate teeth") is an extinct order of marine cartilaginous fish related to modern day chimaera found in what is now the United States of America and Europe.Lund, Richard, E. D. Grogan, and M. Fath. "On the relationships ...
s, had peculiar cycloid cutting teeth. Most of the sharks were marine, but the
Xenacanthida Xenacanthida (or Xenacanthiforms) is a super-order of extinct shark-like elasmobranchs that appeared during the Lower Carboniferous period. The order includes the families Xenacanthidae, Sphenacanthidae, Diplodoselachidae, and Orthacanthidae. T ...
invaded fresh waters of the coal swamps. Among the bony fish, the
Palaeonisciformes The Palaeonisciformes (Palaeoniscida) are an extinct order of early ray-finned fishes ( Actinopterygii). Palaeonisciformes ''sensu lato'' first appeared in the fossil record in the Late Silurian and last appeared in the Late Cretaceous. The na ...
found in coastal waters also appear to have migrated to rivers. Sarcopterygian fish were also prominent, and one group, the
Rhizodont Rhizodontida is an extinct group of predatory tetrapodomorphs known from many areas of the world from the Givetian through to the Pennsylvanian - the earliest known species is about 377 million years ago (Mya), the latest around 310 Mya. Rhizodo ...
s, reached very large size. Most species of Carboniferous marine fish have been described largely from teeth, fin spines and dermal ossicles, with smaller freshwater fish preserved whole. Freshwater fish were abundant, and include the genera '' Ctenodus'', ''Uronemus'', ''
Acanthodes ''Acanthodes'' (from el, ἄκανθώδης , 'provided with spines') is an extinct genus of spiny shark. Fossils have been found in Europe, North America, Asia, and Australia. ''Acanthodes'' was most common in the Carboniferous and Early Perm ...
'', ''Cheirodus'', and '' Gyracanthus''.
Chondrichthyes Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. ...
(especially the ''Stethacanthids'') underwent a major
evolutionary radiation An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. Radiations may affect one clade or many, and be rapid ...
during the Carboniferous. It is believed that this evolutionary radiation occurred because the decline of the
placoderms Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally 'plate-skinned') is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were ...
at the end of the Devonian Period caused many environmental niches to become unoccupied and allowed new organisms to evolve and fill these niches. As a result of the evolutionary radiation Carboniferous sharks assumed a wide variety of bizarre shapes including '' Stethacanthus'' which possessed a flat brush-like dorsal fin with a patch of denticles on its top. '' Stethacanthus'' unusual fin may have been used in mating rituals. File:Stethacanthus BW.jpg, '' Akmonistion'' of the
Holocephali Holocephali ("complete heads"), sometimes given the term Euchondrocephali, is a subclass of cartilaginous fish in the class Chondrichthyes. The earliest fossils are of teeth and come from the Devonian period. Little is known about these primitiv ...
order Symmoriida roamed the oceans of the early Carboniferous. File:Falcatus.jpg, ''
Falcatus ''Falcatus'' is an extinct genus of falcatid chondrichthyan which lived during the early Carboniferous Period in Bear Gulch bay in what is now Montana. Description This fish was quite small, only getting to around 25–30 cm or 10-12 i ...
'' was a Carboniferous holocephalan, with a high degree of sexual dimorphism. File:Dracopristis hoffmanorum.png, '' Dracopristis'' was a
Ctenacanthiform Ctenacanthiformes is an extinct order of chondrichthyan fish. They possessed ornamented fin spines and cladodont dentition. Members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of ...
elasmobranch from the late Carboniferous of
New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...
. File:Ornithoprion hertwigi.png, Ornithoprion was a small-sized Eugeneodont holocephalan that had an elongated lower jaw. File:Allenypterus montanus (Restoration) (cropped).jpg, '' Allenypterus'' was a
Coelacanth The coelacanths ( ) are fish belonging to the order Actinistia that includes two extant species in the genus ''Latimeria'': the West Indian Ocean coelacanth (''Latimeria chalumnae''), primarily found near the Comoro Islands off the east coast ...
fish known from the
Bear Gulch Limestone The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often consider ...
in
Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...
. File:Echinochimaera meltoni (fossil fish) (Bear Gulch Limestone, Upper Mississippian; Montana, USA) (33784748875).jpg, A fossil of '' Echinochimaera'', a fish known from the
Bear Gulch Limestone The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often consider ...
in Montana File:†Phanerosteon phonax Carboniferous Bear Gulch.jpg, '' Phanerosteon'' was a Bony fish belonging to the extinct order
Palaeonisciformes The Palaeonisciformes (Palaeoniscida) are an extinct order of early ray-finned fishes ( Actinopterygii). Palaeonisciformes ''sensu lato'' first appeared in the fossil record in the Late Silurian and last appeared in the Late Cretaceous. The na ...
. File:Rhizodus.jpg, ''
Rhizodus ''Rhizodus'' (root tooth) is an extinct genus of basal, finned tetrapodomorphs (the group of sarcopterygians that contains modern tetrapods and their extinct relatives). It belonged to Rhizodontida, one of the earliest-diverging tetrapodomorph c ...
'' was a large freshwater
Rhizodont Rhizodontida is an extinct group of predatory tetrapodomorphs known from many areas of the world from the Givetian through to the Pennsylvanian - the earliest known species is about 377 million years ago (Mya), the latest around 310 Mya. Rhizodo ...
sarcopterygian Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass includ ...
from Europe and North America. File:Squatinactis NT small.jpg, ''
Squatinactis ''Squatinactis'' is a genus of extinct Elasmobranchii, elasmobranch Chondrichthyes known from the Carboniferous aged Bear Gulch Limestone, Bear gulch limestone in Montana. This fish was discovered in 1974 by Richard Lund. The Holotype, type speci ...
'', a genus of
Elasmobranch Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of g ...
fish from Montana


Tetrapods

Carboniferous amphibians were diverse and common by the middle of the period, more so than they are today; some were as long as 6 meters, and those fully terrestrial as adults had scaly skin. They included a number of basal tetrapod groups classified in early books under the Labyrinthodontia. These had long bodies, a head covered with bony plates and generally weak or undeveloped limbs. The largest were over 2 meters long. They were accompanied by an assemblage of smaller amphibians included under the
Lepospondyli Lepospondyli is a diverse taxon of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco ('' Diplocaulus minumus''), lepospondyls lived from the Early Carboniferous ( Mississippian) to the Early Pe ...
, often only about long. Some Carboniferous amphibians were aquatic and lived in rivers ('' Loxomma'', '' Eogyrinus'', ''
Proterogyrinus ''Proterogyrinus'' is an extinct genus of early tetrapods from the order Embolomeri. Fossil remains of ''Proterogyrinus'' have been found in Scotland, UK, and West Virginia, United States, and date back to the Serpukhovian (mid-Carboniferous pe ...
''); others may have been semi-aquatic ('' Ophiderpeton'', ''
Amphibamus ''Amphibamus'' is a genus of amphibamid temnospondyl amphibians from the Carboniferous (middle Pennsylvanian) of North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisp ...
'', ''
Hyloplesion ''Hyloplesion'' is an extinct genus of microbrachomorph microsaur. It is the type and only genus within the family Hyloplesiontidae. Fossils have been found from the Czech Republic near the towns of Plzeň, Nýřany, and Třemošná, and da ...
'') or terrestrial (''
Dendrerpeton ''Dendrerpeton'' (from el, δένδρον , 'tree' and el, ἑρπετόν , 'creeping thing') is a genus of an extinct group of temnospondyl amphibians. Its fossils have been found primarily in the Joggins Formation of Eastern Canada and in ...
'', '' Tuditanus'', '' Anthracosaurus''). The Carboniferous Rainforest Collapse slowed the evolution of amphibians who could not survive as well in the cooler, drier conditions. Amniotes, however, prospered due to specific key adaptations. One of the greatest evolutionary innovations of the Carboniferous was the amniote egg, which allowed the laying of eggs in a dry environment, as well as keratinized scales and claws, allowing for the further exploitation of the land by certain
tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct t ...
s. These included the earliest sauropsid reptiles (''
Hylonomus ''Hylonomus'' (; ''hylo-'' "forest" + ''nomos'' "dweller") is an extinct genus of reptile that lived 312 million years ago during the Late Carboniferous period. It is the earliest unquestionable reptile (''Westlothiana'' is older, but in fact it ...
''), and the earliest known
synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ...
(''
Archaeothyris ''Archaeothyris'' is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, ''Archaeothyris'', along with a more poorly known synapsid called '' Echinerpe ...
''). Synapsids quickly became huge and diversified in the
Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...
, only for their dominance to stop during the Mesozoic Era. Sauropsids (reptiles, and also, later, birds) also diversified but remained small until the Mesozoic, during which they would dominate the land, as well as the water and sky. Reptiles underwent a major evolutionary radiation in response to the drier climate that preceded the rainforest collapse. By the end of the Carboniferous Period, amniotes had already diversified into a number of groups, including several
families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...
of synapsid
pelycosaur Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term ''mammal-like reptile'' had been used, and pelycosaur was considered an order, but this is ...
s, protorothyridids,
captorhinids Captorhinidae (also known as cotylosaurs) is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late Carboniferous to the Late Permian. They had a cosmopolitan distribution across Pangea. Description C ...
,
sauria Sauria is the clade containing the most recent common ancestor of archosaurs (such as crocodilians, dinosaurs, etc.) and lepidosaurs ( lizards and kin), and all its descendants. Since most molecular phylogenies recover turtles as more closely ...
ns and araeoscelids. File:Pederpes22small.jpg, The amphibian-like '' Pederpes'', the most primitive tetrapod found in the Mississippian, and known from Scotland. File:Hylonomus BW.jpg, ''
Hylonomus ''Hylonomus'' (; ''hylo-'' "forest" + ''nomos'' "dweller") is an extinct genus of reptile that lived 312 million years ago during the Late Carboniferous period. It is the earliest unquestionable reptile (''Westlothiana'' is older, but in fact it ...
'', the earliest sauropsid reptile, appeared in the Pennsylvanian, and is known from the
Joggins Formation The Joggins Formation is a geologic formation in Nova Scotia. It preserves fossils dating back to the Carboniferous period, including ''Hylonomus'', the earliest known reptile. In addition to fossils, the Joggins Formation was a valuable source of ...
in Nova Scotia, and possibly
New Brunswick New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. It is the only province with both English and ...
. File:Petrolacosaurus BW.jpg, ''
Petrolacosaurus ''Petrolacosaurus'' ("rock lake lizard") is an extinct genus of diapsid reptile from the late Carboniferous period. It was a small, long reptile, and the earliest known reptile with two temporal fenestrae (holes at the rear part of the skull ...
'', the earliest known
diapsid Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The group first appeared about three hundred million years a ...
reptile, lived during the late Carboniferous. File:Archaeothyris BW.jpg, ''
Archaeothyris ''Archaeothyris'' is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, ''Archaeothyris'', along with a more poorly known synapsid called '' Echinerpe ...
'' is the oldest known
synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ...
, and is found in rocks from
Nova Scotia Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native Eng ...
. File:Coloraderpeton.jpg, '' Coloraderpeton'' was a
snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...
-like aïstopod
tetrapodomorph The Tetrapodomorpha (also known as Choanata) are a clade of vertebrates consisting of tetrapods (four-limbed vertebrates) and their closest sarcopterygian relatives that are more closely related to living tetrapods than to living lungfish. Advance ...
from the late Carboniferous of
Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
. File:Crassygyrinus scoticusDB (flipped).jpg, ''Crassygyrinus'' was a carnivorous stem-tetrapod from the
early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * ...
of Scotland. File:Microbrachis BW.jpg, '' Microbrachis'' was a
lepospondyl Lepospondyli is a diverse taxon of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco (''Diplocaulus minumus''), lepospondyls lived from the Early Carboniferous ( Mississippian) to the Early Per ...
amphibian known from the
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
. File:Amphibamus BW.jpg, ''
Amphibamus ''Amphibamus'' is a genus of amphibamid temnospondyl amphibians from the Carboniferous (middle Pennsylvanian) of North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisp ...
'' was a
dissorophoid Dissorophoideans are a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and the Early Triassic of Gondwana. They are distinguished by various details of the ...
temnospondyl Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carbo ...
from the Late Carboniferous of
Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...
.


Fungi

As plants and animals were growing in size and abundance in this time (for example, ''
Lepidodendron ''Lepidodendron'' is an extinct genus of primitive vascular plants belonging to the family Lepidodendraceae, part of a group of Lycopodiopsida known as scale trees or arborescent lycophytes, related to quillworts and lycopsids (club mosses). Th ...
''), land
fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
diversified further. Marine fungi still occupied the oceans. All modern classes of fungi were present in the Late Carboniferous ( Pennsylvanian Epoch). During the Carboniferous, animals and bacteria had great difficulty with processing the lignin and
cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell w ...
that made up the gigantic trees of the period. Microbes had not evolved that could process them. The trees, after they died, simply piled up on the ground, occasionally becoming part of long-running wildfires after a lightning strike, with others very slowly degrading into
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...
. White rot fungus were the first organisms to be able to process these and break them down in any reasonable quantity and timescale. Thus, some have proposed that fungi helped end the Carboniferous Period, stopping accumulation of undegraded plant matter, although this idea remains highly controversial.


Extinction events


Romer's gap

The first 15 million years of the Carboniferous had very limited terrestrial fossils. This gap in the fossil record is called
Romer's gap Romer's gap is an example of an apparent gap in the tetrapod fossil record used in the study of evolutionary biology. Such gaps represent periods from which excavators have not yet found relevant fossils. Romer's gap is named after paleontologist ...
after the American palaentologist
Alfred Romer Alfred Sherwood Romer (December 28, 1894 – November 5, 1973) was an American paleontologist and biologist and a specialist in vertebrate evolution. Biography Alfred Romer was born in White Plains, New York, the son of Harry Houston Romer an ...
. While it has long been debated whether the gap is a result of fossilisation or relates to an actual event, recent work indicates the gap period saw a drop in atmospheric oxygen levels, indicating some sort of
ecological collapse Ecological collapse refers to a situation where an ecosystem suffers a drastic, possibly permanent, reduction in carrying capacity for all organisms, often resulting in mass extinction. Usually, an ecological collapse is precipitated by a disast ...
. The gap saw the demise of the Devonian fish-like
ichthyostegalia Ichthyostegalia is an order of extinct amphibians, representing the earliest landliving vertebrates. The group is thus an evolutionary grade rather than a clade. While the group are recognized as having feet rather than fins, most, if not all, ...
n labyrinthodonts, and the rise of the more advanced
temnospondyl Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carbo ...
and
reptiliomorpha Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was def ...
n amphibians that so typify the Carboniferous terrestrial vertebrate fauna.


Carboniferous rainforest collapse

Before the end of the Carboniferous Period, an extinction event occurred. On land this event is referred to as the Carboniferous Rainforest Collapse (CRC). Vast tropical rainforests collapsed suddenly as the climate changed from hot and humid to cool and arid. This was likely caused by intense
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 a drop in sea levels. The new climatic conditions were not favorable to the growth of rainforest and the animals within them. Rainforests shrank into isolated islands, surrounded by seasonally dry habitats. Towering
lycopsid Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...
forests with a heterogeneous mixture of vegetation were replaced by much less diverse tree-fern dominated flora. Amphibians, the dominant vertebrates at the time, fared poorly through this event with large losses in biodiversity; reptiles continued to diversify due to key adaptations that let them survive in the drier habitat, specifically the hard-shelled egg and scales, both of which retain water better than their amphibian counterparts.


See also

* Carboniferous tetrapods * Carboniferous Rainforest Collapse * Important Carboniferous Lagerstätten **
East Kirkton Quarry East Kirkton Quarry is a former limestone quarry in West Lothian, Scotland (East Kirkton Limestone), now better known as a fossil site known for terrestrial fossils from the fossil-poor Romer's gap, a 15 million year period at the beginning of th ...
; c. 350 mya;
Bathgate Bathgate ( sco, Bathket or , gd, Both Chèit) is a town in West Lothian, Scotland, west of Livingston, Scotland, Livingston and adjacent to the M8 motorway (Scotland), M8 motorway. Nearby towns are Armadale, West Lothian, Armadale, Blackburn, ...
, Scotland **
Hamilton Quarry Hamilton Quarry is a Late Carboniferous lagerstätte near Hamilton, Kansas, United States. It has a diverse assemblage of unusually well-preserved marine, euryhaline, freshwater, flying, and terrestrial fossils (invertebrates, vertebrates, and pl ...
; 320 mya;
Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to th ...
, US **
Mazon Creek The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concreti ...
; 300 mya;
Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockf ...
, US *
List of fossil sites This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of t ...
''(with link directory)''


References


Sources

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *


External links

*
Examples of Carboniferous Fossils60+ images of Carboniferous Foraminifera
{{Authority control Geological periods