In the

geologic time scale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochrono ...

, the Changhsingian or Changxingian is the latest

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

or uppermost

stage Stage or stages may refer to: 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 British theatre newspaper * Sta ...

of the

Permian The Permian ( ) is a geologic period and 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 of the Paleoz ...

. It is also the upper or latest of two subdivisions of the

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms l ...

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

Series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used i ...

. The Changhsingian lasted from to 251.902 million years ago (Ma). It was preceded by the

Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. The ...

and followed by the

Induan The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is sometimes ...

. The greatest

mass extinction An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. It ...

in the

Phanerozoic The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 538.8 million years to the present, and it began with the Cambrian Period, when anima ...

eon Eon or Eons may refer to: Time * Aeon, an indefinite long period of time * Eon (geology), a division of the geologic time scale Arts and entertainment Fictional characters * Eon, in the 2007 film ''Ben 10: Race Against Time'' * Eon, in the ...

, the

Permian–Triassic extinction event The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as ...

, occurred during this age. The extinction rate peaked about a million years before the end of this stage.

Stratigraphic definitions

The Changhsingian is named after

Changxing () is a county of the prefecture-level city of Huzhou, in the northwest of Zhejiang province, China. Situated on the southwest shore of Lake Tai, it borders the provinces of Jiangsu to the north and Anhui to the west. It has a total area of an ...

() in northern

Zhejiang Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Jiang ...

, China. The stage was named for the Changhsing Limestone. The name was first used for a stage in 1970; 1973: ''Permian stages names'', in: : ''The Permian and Triassic systems and their mutual boundary'',

Canadian Society of Petroleum Geologists The Canadian Society of Petroleum Geologists (CSPG) is a professional geological society in Canada. The CSPG works to advance the science of geology, foster professional development of members and promote community awareness of the profession. The ...

Memoir 2, pp 522–548. and was anchored in the international timescale in 1981.; 2006: ''The Global Boundary Stratotype Section and Point (GSSP) for the base of Changhsingian Stage (Upper Permian)'' Episodes 29(3), p. 175-182
PDF
The base of the Changhsingian Stage is at the first appearance of the

conodont Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...

species ''

Clarkina ''Clarkina'' is an extinct genus of conodonts. It is considered to be an offshore, outer shelf or basinal, deep-water taxon. The genus name is a tribute to David Leigh Clark. Synonyms ''Clarkina'' Soodan 1975 is a junior synonym for the preh ...

wangi''. The global reference profile is profile D at

Meishan Meishan (; Sichuanese Pinyin: Mi2san1; local pronunciation: ; ), formerly known as Meizhou () or Qingzhou (), is a prefecture-level city with 2,955,219 inhabitants as of 2020 census whom 1,232,648 lived in the built-up (or metro) area made of th ...

, in the type area in Changxing. The top of the Changhsingian (the base of the Induan Stage and the Triassic

System A system is a group of Interaction, 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 (systems), environment, is described by its boundaries, ...

is at the first appearance of the conodont species '' Hindeodus parvus''. The Changhsingian stage contains only one

ammonite 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) ...

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

: that of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Iranites''.

Palaeontology

The Changhsingian ended with the

when both global biodiversity and

alpha diversity In ecology, alpha diversity (α-diversity) is the mean species diversity in a site at a local scale. The term was introduced by R. H. WhittakerWhittaker, R. H. (1960) Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monograp ...

(community-level diversity) were devastated. The world after the extinction was almost lifeless, deserted, hot, and dry.

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 cuttle ...

fishes Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

insects 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 pairs of j ...

, and the

tetrapods 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 therapsids ...

(

cynodonts The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety ...

amphibians Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbore ...

reptiles Reptiles, as most commonly defined are the animals in the Class (biology), class Reptilia ( ), a paraphyletic grouping comprising all sauropsid, sauropsids except birds. Living reptiles comprise turtles, crocodilians, Squamata, squamates (lizar ...

therapsids Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented mor ...

, etc.) remained rare and terrestrial ecosystems did not recover for 30 million years.

References

External links

GeoWhen Database - ChanghsingianUpper Paleozoic stratigraphic chart
at the website of the subcommission for stratigraphic information of the ICS {{Geological history, p, p Permian geochronology Geological ages