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

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 ...

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 The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

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 The Gzhelian ( ) is an age in the ICS geologic time scale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from to Ma. It follows the Ka ...

) 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 Ishimbay (; ) is a types of inhabited localities in Russia, town in the Republic of Bashkortostan, Russia, located on the banks of the Belaya River (Kama), Belaya and Tayruk Rivers, south of Ufa. Population: Administrative and municipal stat ...

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 ''Streptognathodus'' is an extinct genus of conodonts from the Late Carboniferous to Early Permian. Use in stratigraphy Late Carboniferous The top of the Kasimovian stage is close to the first appearance of ''Streptognathodus zethus''. The ...

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 Aktobe (, ; ) is a major city located on the Ilek River in western Kazakhstan. It serves as the administrative center of the Aktobe Region and is an important cultural, economic, and industrial hub in the region. As of 2023, the city has a popu ...

in the Ural Mountains of Kazakhstan.

Geography

The World of the Carboniferous-Permian boundary

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

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 The Variscan orogeny, or Hercynian orogeny, was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan ...

continued. This created the large supercontinent,

Pangea Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia (continent), Siberia during the Carboniferous period ...

, 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 lycophytes, when broadly circumscribed, are a group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineage ...

. The series saw the appearance of beetles and flies. The coal swamps from the

declined but the herbivores,''

Diadectes ''Diadectes'' (meaning ''crosswise-biter'') is an extinct genus of large reptiliomorphs or synapsids that lived during the early Permian period ( Artinskian- Kungurian stages of the Cisuralian epoch, between 290 and 272 million years ago). ''Dia ...

''and ''

Edaphosaurus ''Edaphosaurus'' (, meaning "pavement lizard" for dense clusters of its teeth) is a genus of extinct edaphosaurid synapsids that lived in what is now North America and Europe around 303.4 to 272.5 million years ago, during the Late Carboniferous ...

'' persisted until the end of this series, approximately. The dry interior had small insectivores.

Caseids Caseidae are an Extinction, extinct Family (biology), family of Basal (phylogenetics), basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the so ...

and prototherapsid''

Tetraceratops ''Tetraceratops insignis'' ("four-horned face emblem") is an extinct synapsid from the Early Permian that was formerly considered the earliest known representative of Therapsida, a group that includes mammals and their close extinct relatives. It ...

'' made their appearance. The marine life was probably more diverse than modern times as the climate warmed. Unusual sharks such as ''

Helicoprion ''Helicoprion'' is an Extinction, extinct genus of shark-like Chondrichthyes, cartilaginous fish in the order Eugeneodontiformes. Almost all ''Helicoprion'' Fossil, fossils consist of spirally-arranged clusters of fused teeth, called "tooth whor ...

'' continued in this series. Early Permian terrestrial faunas were dominated by

pelycosaurs Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile was used, and Pelycosauria was considered an order, but this is now thoug ...

(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 Diadectidae is an extinct family (biology), family of early tetrapods that lived in what is now North America and Europe during the Late Carboniferous and Early Permian, and in Asia during the Late Permian. They were the first herbivorous tetrapo ...

, 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 Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

, and reached their apex in the Cisuralian remaining the dominant land animals for some 40 million years. A few continued into 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 t ...

. They were succeeded by the therapsids. File:Dimetrodon grandis.jpg, ''

Dimetrodon ''Dimetrodon'' ( or ; ) is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian (Early Permian) Epoch (geology), epoch of the Permian period, around 295–272 million years ago. With most species measuring long and ...

'', a

pelycosaur Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile was used, and Pelycosauria was considered an order, but this is now thoug ...

, was at the top of the food chain in the Cisuralian File:Helicoprion bessonovi cropped.png, ''

bessonovi'' with characteristic 'tooth-whorl' at front of jaw

Subdivisions

Global

Asselian In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between and million years ago (Ma ...

stage (298.9 ± 0.15 – 294.6 ± 0.8 Ma) *

Sakmarian In the geologic timescale, the Sakmarian is an age or stage of the Permian period. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and fo ...

stage (294.6 ± 0.8 – 290.1 ± 0.7 Ma) *

Artinskian In the geologic timescale, the Artinskian is an age (geology), age or stage (stratigraphy), stage of the Permian. It is a subdivision of the Cisuralian Epoch (geology), Epoch or series (stratigraphy), Series. The Artinskian likely lasted between ...

stage (290.1 ± 0.7 – 283.5 ± 0.7 Ma) *

Kungurian In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between and million years ago (Ma). It was preceded by the Arti ...

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