The Cisuralian, also known as the Early Permian, is the first series/

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 ...

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 ...

. The Cisuralian was preceded by the Pennsylvanian and followed by the

Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico an ...

. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Ma. In the regional stratigraphy of southwestern North America, the Cisuralian encompasses two series: the Wolfcampian (Asselian to mid-Artinskian) and Leonardian (mid-Artinskian to Kungurian). The series saw the appearance of

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s and

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

and was a relatively stable warming period of about 21 million years.

Name and background

The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch ( Gzhelian) and is followed by the Permian

Epoch. The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan. Limestones on the edge of Russian Platform and make up the Ishimbay oil fields. These oil fields were vital to the Soviet Union during WW2 when the Germans controlled the oil fields to the west. The International Chronostratigraphic Chart (v2018/07) provides a numerical age of 298.9 ± 0.15 – 272.3 ± 0.5 Ma. The base of the Cisuralian series and the Permian

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 defined as the place in the stratigraphic record where fossils of the conodont '' Streptognathodus isolatus'' first appear. The global reference profile for the base (the GSSP or golden spike) is located in the valley of the Aidaralash River, near Aqtöbe in the Ural Mountains of Kazakhstan.

Geography

The World of the Carboniferous-Permian boundary

Gondwana collided with

Laurussia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around (Million years ago, Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during ...

and created the Alleghenian orogeny in present-day North America. In northwestern Europe, the Hercynian orogeny continued. This created the large supercontinent, Pangea, by the middle of the early Permian, which was to have an impact on the climate.

Climate

At the start of the Permian, the Late Palaeozoic Ice Age, which began in 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 ...

, was at its peak.

Glaciers A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

receded over the course of the late Cisuralian as the Earth's climate gradually warmed, particularly during the Artinskian Warming Event, drying the continent's interiors.Palaeos: Life Through Deep Time > The Permian Period
Accessed 1 April 2013. The pan-tropical belt of Pangaea experienced particularly significant aridification during this epoch.

Biodiversity

The swampy fringes were mostly ferns, seed ferns, and lycophytes. The series saw the appearance of beetles and flies. The coal swamps from the

declined but the herbivores,'' Diadectes ''and '' Edaphosaurus'' persisted until the end of this series, approximately. The dry interior had small insectivores. Caseids and prototherapsid'' Tetraceratops'' made their appearance. The marine life was probably more diverse than modern times as the climate warmed. Unusual sharks such as '' Helicoprion'' continued in this series. Early Permian terrestrial faunas were dominated by pelycosaurs (a paraphyletic group of early

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 ...

), diadectids, and

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...

s,Huttenlocker, A. K., and E. Rega. 2012. The Paleobiology and Bone Microstructure of Pelycosaurian-grade Synapsids. Pp. 90–119 in A. Chinsamy (ed.) Forerunners of Mammals: Radiation, Histology, Biology. Indiana University Press. The pelycosaurs appeared during the Late Carboniferous, and reached their apex in the Cisuralian remaining the dominant land animals for some 40 million years. A few continued into the Capitanian. They were succeeded by the therapsids. File:Dimetrodon grandis.jpg, '' Dimetrodon'', a pelycosaur, was at the top of the food chain in the Cisuralian File:Helicoprion bessonovi cropped.png, '' Helicoprion bessonovi'' with characteristic 'tooth-whorl' at front of jaw

Subdivisions

Global

* Asselian stage (298.9 ± 0.15 – 294.6 ± 0.8 Ma) * Sakmarian stage (294.6 ± 0.8 – 290.1 ± 0.7 Ma) * Artinskian stage (290.1 ± 0.7 – 283.5 ± 0.7 Ma) * Kungurian stage (283.5 ± 0.7 – 272.3 ± 0.5 Ma)

Regional

*New Zealand **Telfordian (289 – 278 Ma) **Mangapirian (278 – 270.6 Ma)

References

{{Geological history, p, m Geological epochs *01