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 geochro ...

, the Changhsingian or Changxingian is the latest

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 ...

or uppermost stage 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 251.902 Mya. It is the s ...

. 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 te ...

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 b ...

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 251.9 Ma ago. It is 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 S ...

age/stage and is 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 251.9 Ma and 249.9 Ma (million years ago). The Induan is so ...

age/stage (

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

epoch). 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 fall in the diversity and abundance of multicellular organisms. It occ ...

in the

Phanerozoic The Phanerozoic is the current and the latest of the four eon (geology), geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and ...

eon, the

Permian–Triassic extinction event The Permian–Triassic extinction event (also known as the P–T extinction event, the Late Permian extinction event, the Latest Permian extinction event, the End-Permian extinction event, and colloquially as the Great Dying,) was an extinction ...

, occurred around the end of this age.

Stratigraphic definitions

The Changhsingian is named after Changxing () in northern

Zhejiang ) , translit_lang1_type2 = , translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese) , image_skyline = 玉甑峰全貌 - panoramio.jpg , image_caption = View of the Yandang Mountains , image_map = Zhejiang i ...

, China. The stage was named for the Changhsing Limestone. The name was first used for a stage in 1970 and was anchored in the international timescale in 1981.. The base of the Changhsingian Stage is at 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 ...

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

Meishan natively Meishan ( zh, s=眉山; Sichuanese Pinyin: Mi2san1; local pronunciation: ; zh, p=Méishān , w=Mei-shan), formerly known as Meizhou () or Qingzhou (), is a prefecture-level city with 2,955,219 inhabitants as of 2020 census of whom ...

, in the type area in Changxing, just below the Changhsingian foraminifer index fossil '' Palaeofusulina'' and the first appearance of the ammonoid '' Tapashanites''. The top of the Changhsingian (the base of the

Stage and the Triassic

System 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 open system (systems theory), environment, is described by its boundaries, str ...

) is at the first appearance of the conodont species '' Hindeodus parvus''. In the second part of the 20th century, appearance of the

ammonite 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 ...

'' Otoceras'', that existed no more than 100,000 years, in the boreal region was considered a marker of the Lower Triassic boundary. However, a more detailed study of Lower Induan biostratigraphy revealed the diachronicity of the appearance of these mollusks in different regions of the Earth. The Changhsingian contains only one ammonoid biozone: that of the

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 ...

'' Iranites''.

Changhsingian life

The Changhsingian ended with the

, the largest

event of the

Era, when both global biodiversity and alpha diversity (community-level diversity) were devastated. On land, the Changhsingian fauna comprised gorgonopsid

synapsids Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...

like ''

Inostrancevia ''Inostrancevia'' is an extinction, extinct genus of large carnivorous therapsids which lived during the Late Permian in what is now European Russia and Southern Africa. The first-known fossils of this gorgonopsian were discovered in the context ...

'',

anomodont Anomodontia is an extinct group of non-mammalian therapsids from the Permian and Triassic periods. By far the most speciose group are the dicynodonts, a clade of beaked, tusked herbivores. Anomodonts were very diverse during the Middle Pe ...

synapsids like '' Daptocephalus'' and '' Dicynodon'', and parareptiles like ''

Elginia ''Elginia'' is an extinct genus of pareiasaurid known from the Late Permian of Scotland and China. It was named for the area around Elgin, Moray, Elgin in Scotland, which has yielded many fossils referred to as the Elgin Reptiles. Discovery ...

'', milleretids and '' Nanoparia''. Among fishes, the bobasatraniiforms ''

Bobasatrania ''Bobasatrania'' is an extinct genus of prehistoric marine Actinopterygii, ray-finned fish that survived the Permian-Triassic extinction event. Fossils of ''Bobasatrania'' were found in beds of Changhsingian (Lopingian, late Permian) to Ladinian ...

'' and '' Ebenaqua'' are known from Changhsingian deposits of Greenland and Australia, respectively. Another deep-bodied fish, '' Sinoplatysomus'', is known from

province of China, along with the elongate saurichthyiform '' Eosaurichthys'' and the coelacanths '' Changxingia'' and '' Youngichthys''. Within the Eugeneodontida, the helicoprionids are represented by the genus '' Sinohelicoprion''; as well as some edestids such as '' Helicampodus''; and other eugeneodontids. Several fish

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 ...

were described from Changhsingian deposits of Russia and South Africa. The Hambast Formation of Iran yielded chondrichthyan faunas of

to Changhsingian age. The

'' Vjalovognathus carinatus'' is known from the Selong Formation of Tibet; more common conodonts include the genera '' Clarkina'' and ''

Hindeodus ''Hindeodus'' is an extinct genus of conodonts in the family Anchignathodontidae. The generic name ''Hindeodus'' is a tribute to George Jennings Hinde, a British geologist and paleontologist from the 1800s and early 1900s. The suffix -odus typica ...

''. Changhsingian aged beds of the Tesero Member of the Werfen Formation produced fossils of a

crown 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 ...

echinoid, '' Eotiaris teseroensis'' and other

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

. The '' Paratirolites'' Limestone near Julfa (

Azerbaijan Azerbaijan, officially the Republic of Azerbaijan, is a Boundaries between the continents, transcontinental and landlocked country at the boundary of West Asia and Eastern Europe. It is a part of the South Caucasus region and is bounded by ...

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

) contains a diverse pre-extinction ammonoid fauna, including the

'' Neoaganides'', '' Pseudogastrioceras'', '' Dzhulfites'', ''Paratirolites'', '' Julfotirolites'', '' Alibashites'', '' Abichites'', '' Stoyanowites'' and '' Arasella'' The ''Bellerophon'' Formation in northern Italy documents a pre-extinction

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

community with 26 species adapted to stressful conditions (high temperatures, high salinity, shallow water depths, low oxygen and high terrigenous input). The formation is otherwise known for abundant '' Bellerophon'' fossils. Only a few

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

genera are present by the Changhsingian. The last of the Trilobita include the genus Kathwaia of

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

. Perhaps the most widespread and diverse genus was Pseudophillipsia, other genera include Acropyge, Cheiropyge, and Paraphillipsia. In Australia, fossils of one of the last surviving

eurypterids Eurypterids, often informally called sea scorpions, are a group of extinct marine 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 ...

, '' Woodwardopterus? freemanorum'', were found.

Notable formations

* Ali Bashi Formation (

Armenia Armenia, officially the Republic of Armenia, is a landlocked country in the Armenian Highlands of West Asia. It is a part of the Caucasus region and is bordered by Turkey to the west, Georgia (country), Georgia to the north and Azerbaijan to ...

) * ''Bellerophon'' Formation (

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

) * Dalong formation (

Yangtze The Yangtze or Yangzi ( or ) is the longest river in Eurasia and the third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows including Dam Qu River the longest source of the Yangtze, i ...

, China) * Hambast Formation (Iran) * Hopeman Sandstone Formation (

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

) * Moradi Formation (

Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...

) * Quartermaster Formation (

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, USA) * Schuchert Dal Formation (

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

) * Tesero Member of the Werfen Formation (

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

Bosnia and Herzegovina Bosnia and Herzegovina, sometimes known as Bosnia-Herzegovina and informally as Bosnia, is a country in Southeast Europe. Situated on the Balkans, Balkan Peninsula, it borders Serbia to the east, Montenegro to the southeast, and Croatia to th ...

, Italy) * Lower part of Wordie Creek Formation (Greenland)

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 Lopingian