The Serpukhovian is in the ICS

geologic timescale 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 geochron ...

the uppermost

stage Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly Brit ...

or youngest

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

of the

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

, the lower

subsystem A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and is exp ...

of the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

. The Serpukhovian age lasted from Ma to Ma. It is preceded by the Visean and is followed by the

Bashkirian The Bashkirian is in the International Commission on Stratigraphy geologic timescale the lowest stage (stratigraphy), stage or oldest age (geology), age of the Pennsylvanian (geology), Pennsylvanian. The Bashkirian age lasted from to Mega annu ...

. The Serpukhovian correlates with the lower part of the

Namurian The Namurian is a stage in the regional stratigraphy of northwest Europe, with an age between roughly 331 and 319 Ma (million years ago). It is a subdivision of the Carboniferous system or period, as well as the regional Silesian series. The Na ...

Stage of European stratigraphy and the middle and upper parts of the

Chesterian The Mississippian ( ), also known as Lower Carboniferous or Early Carboniferous, is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from rough ...

Stage of North American stratigraphy.

Name and definition

The Serpukhovian Stage was proposed in 1890 by Russian stratigrapher Sergei Nikitin and was introduced in the official stratigraphy of European Russia in 1974. It was named after the city of

Serpukhov Serpukhov ( rus, Серпухов, p=ˈsʲerpʊxəf) is a types of inhabited localities in Russia, city in Moscow Oblast, Russia, located at the confluence of the Oka River, Oka and the Nara (Oka), Nara Rivers, 99 kilometers (62 miles) south fro ...

, near

Moscow Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...

. The ICS later used the upper Russian subdivisions of the Carboniferous in its international geologic time scale. The base of the Serpukhovian is informally defined by the first appearance of the

conodont Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ...

'' Lochriea ziegleri'', though the utility and systematic stability of this species is not yet certain. No lower

GSSP A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. ...

has been assigned to the Serpukhovian Stage yet. Two candidate GSSPs have been proposed: the Verkhnyaya Kardailovka section in the South

Urals The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, and the Naqing (Nashui) section in

Guizhou ) , image_skyline = , image_caption = , image_map = Guizhou in China (+all claims hatched).svg , mapsize = 275px , map_alt = Map showing the location of Guizhou Province , map_caption = Map s ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. The top of the stage (the base of the

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

subsystem and Bashkirian stage) is at the first appearance of the conodont '' Declinognathodus nodiliferus'' in the lower Bird Spring Formation, which overlies the Battleship Formation in Nevada. It is also slightly above the first appearance of the

foram Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of Rhizarian protists characterized by streaming granular ectoplasm for catching food and other uses; and commonl ...

'' Globivalvulina bulloides'', genozone of the

ammonoid Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Homoceras'' and the ammonoid

biozone In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxon, taxa, as opposed to a Lithostratigraphy, lithostratigraphic unit which is defined by the ...

of '' Isohomoceras subglobosum''.

Subdivision

Biostratigraphy

In Europe, the Serpukhovian Stage includes three conodont biozones: the ''

Gnathodus ''Gnathodus'' is an extinct conodont genus in the family Idiognathodontidae. Use in stratigraphy The Tournaisian, the oldest age of the Mississippian (geology), Mississippian (also known as Lower Carboniferous), contains eight conodont biozon ...

postbilineatus'' Zone (youngest), ''Gnathodus bollandensis'' Zone, and ''Lochriea ziegleri'' Zone (in part, oldest). There are three

foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

biozones: the '' Monotaxinoides transitorius'' Zone (youngest), '' Eostaffellina protvae'' Zone, and '' Neoarchaediscus postrugosus'' Zone (oldest). In North America, the stage encompassed four conodont biozones: the '' Rhachistognathus muricatus'' Zone (youngest), '' Adetognathus unicornis'' Zone, ''

Cavusgnathus ''Cavusgnathus'' is an extinct genus of conodonts. Glen K. Merrill stated in 1963 that "conodont workers have considered ''Idiognathoides'' to be a junior synonym of ''Polygnathodella ''Polygnathodella'' is an extinct genus of conodont. Gl ...

naviculus'' Zone, and ''Gnathodus bilineatus'' Zone (in part, oldest).

Regional subdivisions

In the regional stratigraphy of Russia (and Eastern Europe as a whole), the Serpukhovian is subdivided into four substages, from oldest to youngest: the Tarusian, Steshevian, Protvian, and Zapaltyubian. The former three are found in the

Moscow Basin The Moscow Basin is a major sedimentary basin and tectonic structural feature in the stable East European Craton. It has been widely studied by Russian and Scandinavian geologists. Formation and geological history The Fennoscandia Shield and its ...

and are named after places near Serpukhov (

Tarusa Tarusa () is a types of inhabited localities in Russia, town and the administrative center of Tarussky District in Kaluga Oblast, Russia, located on the left bank of the Oka River, northeast of Kaluga, the administrative center of the oblast. ...

and

Protva The Protva () is a river in the Moscow and Kaluga oblasts in Russia. It is a left tributary of the Oka. It is long, and has a drainage basin of .Donets Basin The Seversky Donets () or Siverskyi Donets (), usually simply called the Donets (), is a river on the south of the East European Plain. It originates in the Central Russian Upland, north of Belgorod, flows south-east through Ukraine (Kharkiv ...

and the

. In the regional stratigraphy of the United Kingdom (and Western Europe as a whole), the Serpukhovian corresponds to the lower half of the

regional stage. This portion of the Namurian includes three substages, from oldest to youngest: the Pendleian, Arnsbergian and Chokierian. Only the lowermost Chokierian falls in the Serpukhovian, the upper part of the substage corresponds to the earliest

. In North America, the Serpukhovian corresponds to the upper part of the

regional stage, while in

the Serpukhovian is roughly equivalent to the Dewuan regional stage.

Serpukhovian extinction

The largest extinction event of the Carboniferous Period occurred in the early Serpukhovian. This extinction came in the form of ecological turnovers, with the demise of diverse Mississippian assemblages of

crinoids Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are ...

and

rugose corals The Rugosa or rugose corals are an extinct class of solitary and colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., '' Caninia'', '' Lophophyllidium'', '' Neozaphrentis'', '' Streptelasma ...

. After the extinction, they were replaced by species-poor cosmopolitan ecosystems. The extinction selectively targeted species with a narrow range of temperature preferences, as cooling seawater led to habitat loss for tropical specialists. Ammonoids appear to have not been impacted by this event, as they reached a zenith in diversity at this time. The long-term ecological impact of the Serpukhovian extinction may have exceeded that of the Ordovician-Silurian extinction, where taxonomic diversity was abruptly devastated but quickly recovered to pre-extinction levels. Sepkoski (1996) plotted an extinction rate of around 23-24% for the Serpukhovian as a whole, based on marine

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

which persist through multiple stages. Bambach (2006) found an early Serpukhovian extinction rate of 31% among all marine genera. Using an

extinction probability In population genetics, extinction probability is the chance of an inherited trait becoming extinct as a function of time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succes ...

procedure generated from the

Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...

, McGhee ''et al''. (2013) estimated an extinction rate as high as 39% for marine genera. On the other hand, Stanley (2016) estimated that the extinction was much smaller, at a loss of only 13-14 % of marine genera. Relative to other biological crises, the Serpukhovian extinction was much more selective in its effects on different evolutionary faunas. Stanley (2007) estimated that the early Serpukhovian saw the loss of 37.5% of marine genera in the Paleozoic evolutionary fauna. Only 15.4% of marine genera in the modern evolutionary fauna would have been lost along the same time interval. This disconnect, and the severity of the extinction as a whole, is reminiscent of the

Late Devonian extinction The Late Devonian mass extinction, also known as the Kellwasser event, was a mass extinction event which occurred around 372 million years ago, at the boundary between the Frasnian and Famennian ages of the Late Devonian period.Racki, 2005McGh ...

events. Another similarity is how the Serpukhovian extinction was seemingly driven by low rates of speciation, rather than particularly high rates of extinction. It is disputed whether the aftermath of the extinction saw a relative stagnation of biodiversity or a major increase. Some studies have found that in the following Late Paleozoic Ice Age (LPIA) of the

Late Carboniferous Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

and

Early Permian 01 or 01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), ''01'' (Richard Müller album), 2001 * 01 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

, both speciation and extinction rates were low, with this stagnation in biological diversity driven by a reduction of carbonate platforms, which otherwise would have helped to maintain high biodiversity. More recent studies have instead argued that biodiversity surged during the LPIA in what is known as the

Carboniferous-Earliest Permian Biodiversification Event The Carboniferous ( ) is a geologic period and system of the Paleozoic era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period ...

(CPBE). Foraminifera especially saw extremely rapid diversification. The CPBE may have been caused by the dramatically increased marine provincialism resulting from sea level fall during the LPIA, combined with the assembly of Pangaea, which limited the spread of taxa from one region of the world ocean to another.

References

External links

Carboniferous timescale
at the website of the Norwegian network of offshore records of geology and stratigraphy

www.palaeos.com {{Geological history, p, p, state=collapsed Mississippian geochronology Geological ages