In the

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 geochr ...

, the Wuchiapingian or Wujiapingian (from in the Liangshan area of

Hanzhong Hanzhong (; abbreviation: Han) is a prefecture-level city in the southwest of Shaanxi province, China, bordering the provinces of Sichuan to the south and Gansu to the west. The founder of the Han dynasty, Liu Bang, was once enfeoffed as th ...

Shaanxi Province Shaanxi (alternatively Shensi, see § Name) is a landlocked province of China. Officially part of Northwest China, it borders the province-level divisions of Shanxi (NE, E), Henan (E), Hubei (SE), Chongqing (S), Sichuan (SW), Gansu (W), Ni ...

) is an age or

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 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 ...

. It is also the lower or earlier 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 in ...

. The Wuchiapingian spans the time between and million years ago (Ma). It was preceded by the

Capitanian In the geologic timescale, the Capitanian is an age or stage of the Permian. It is also the uppermost or latest of three subdivisions of the Guadalupian Epoch or Series. The Capitanian lasted between and million years ago. It was preceded by ...

and followed by the Changhsingian. Regional stages with which the Wuchiapingian is coeval or overlaps include the Djulfian or Dzhulfian, Longtanian, Rustlerian, Saladoan, and Castilian.

Stratigraphic definitions

The Wuchiapingian was first used in 1962, when the Lopingian Series of southwestern China was divided in the Changhsingian and Wuchiapingian Formations. In 1973 the Wuchiapingian was first used as a chronostratigraphic unit (i.e. a stage, as opposed to a formation, which is a

lithostratigraphic Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are primarily igneou ...

unit). The base of the Wuchiapingian Stage is defined as the place in the stratigraphic record where the conodont 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 pre ...

postbitteri postbitteri'' first appears. A global reference profile for this boundary (a

GSSP 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 ...

) is located near

Laibin Laibin (, Zhuang: Laizbinh) is a prefecture-level city in the central part of the Guangxi Zhuang Autonomous Region, China. History Laibin is an ancient town with more than 2000 years of history. The area was settled in prehistoric times, more th ...

in the Chinese province of Guangxi.; 2006: ''The Global Stratotype Section and Point (GSSP) for the boundary between the Capitanian and Wuchiapingian Stage (Permian)'', Episodes 29(4), pp. 253–262 The top of the Wuchiapingian (the base of the Changhsingian) is at the first appearance of conodont species ''

wangi''. The Wuchiapingian contains two ammonite

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 ...

s: that of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' Araxoceras'' and that of the genera '' Roadoceras'' and '' Doulingoceras''.

Biodiversity

An extinction pulse occurred during the Wuchiapingian; faunas were recovering when another larger extinction pulse, 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 ...

devastated life.

Wuchiapingian life

Chondrichthyans

Actinopterygians

Coelacanths

†Temnospondyls

†Chroniosuchians

†Seymouriamorphs

†Procolophonomorphs

Eureptiles

Diapsids

=Archosauromorphs

Synapsids

Therapsids

References

External links

GeoWhen Database - Wuchiapingian

Upper Paleozoic stratigraphic chart
at the website of the subcommission for stratigraphic information of the ICS {{Geological history, p, p Permian geochronology . Lopingian Hanzhong Paleontology in Shaanxi Permian Asia