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 geoch ...

, the Capitanian is an age or stage 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 Pale ...

. 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 the Wordian and followed by the Wuchiapingian.; 2004: ''A Geologic Time Scale 2004'',

Cambridge University , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

Press A significant mass extinction event occurred at the end of this stage, which was associated with

anoxia The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of di ...

and acidification in the oceans and possibly caused by the volcanic eruptions that produced the Emeishan Traps. This extinction event may be related to the much larger

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, a ...

that followed about 10 million years later.

Stratigraphy

The Capitanian Stage was introduced into scientific literature by George Burr Richardson in 1904. The name comes from the Capitan Reef in the Guadalupe Mountains (

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, United States). The Capitanian was first used as a stratigraphic subdivision of the Guadalupian in 1961, when both names were still only used regionally in the southern US. The stage was added to the internationally used

ICS ICS may refer to: Computing * Image Cytometry Standard, a digital multidimensional image file format used in life sciences microscopy * Industrial control system, computer systems and networks used to control industrial plants and infrastructu ...

timescale in 2001.

Definitions

The base of the Capitanian Stage is defined as the place in the stratigraphic record where fossils of

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, w ...

species '' Jinogondolella postserrata'' first appear. The global reference profile for this stratigraphic boundary is located at Nipple Hill in the southern Guadalupe Mountains of Texas. The top of the Capitanian (the base of the Wuchiapingian and Lopingian series) is defined as the place in the stratigraphic record where the conodont species '' Clarkina postbitteri postbitteri'' first appears. The Capitanian Stage was part of the time in which the Zechstein was deposited in Europe. It is coeval with the old European regional Saxonian Stage. In the eastern Tethys domain, the Capitanian overlaps the regional Murgabian Stage, the Midian Stage and the lower part of the Laibinian Stage. In Russia the Capitanian equals the lower part of the regional Severodvinian Stage.

Biostratigraphy

The Capitanian contains 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 cuttle ...

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 ...

(''Timorites'') and three conodont biozones: *zone of '' Clarkina postbitteri hongshuiensis'' *zone of ''Jinogondolella altudaensis'' *zone of ''Jinogondolella postserrata'' Larger fusulinid species permit a division in two biozones: *zone of ''Rausserella'' *zone of ''Afganella schenki''

Biodiversity

Olson’s Extinction, in the early Guadalupian ( Roadian, Wordian), led to an extended period of low diversity when worldwide two-thirds of terrestrial vertebrate life was lost. Global diversity rose dramatically in the Capitanian, probably the result of disaster taxa filling empty guilds, only to fall again when the end-Guadalupian event caused a diversity drop in the Wuchiapingian.

Events

Carbon isotopes in marine

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 wh ...

from the Capitanian age show an increase in δ¹³C values. The change in carbon isotopes in the sea water reflects cooling of global climates. This climatic cooling may have caused the end-Capitanian extinction event among species that lived in warm water, like larger fusulinids (Verbeekninidae), large

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...

s ( Alatoconchidae) and

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 ...

corals, and Waagenophyllidae.

References

External links

GeoWhen Database - CapitanianUpper Paleozoic stratigraphic chart
at the website of the subcommission for stratigraphic information of the ICS {{Geological history, p, p Permian geochronology Guadalupian . Permian geology of Texas