The Guadalupian is the second and middle

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 Guadalupian was preceded by the

Cisuralian The Cisuralian, also known as the Early Permian, is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mou ...

and followed by 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 ...

. It is named after the

Guadalupe Mountains The Guadalupe Mountains () are a mountain range located in West Texas and southeastern New Mexico. The range includes the highest summit in Texas, Guadalupe Peak, , and the "signature peak" of West Texas, El Capitan, both of which are located wi ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

and

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 ...

, and dates between 272.95 ± 0.5 – 259.1 ± 0.4 Mya. The series saw the rise of the therapsids, a minor

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

event called

Olson's Extinction Olson's Extinction was a mass extinction that occurred in the late Cisuralian or early Guadalupian epoch of the Permian period, predating the much larger Permian–Triassic extinction event. The event is named after American paleontologist E ...

and a significant

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 ...

called the

end-Capitanian extinction event The Capitanian mass extinction event (also known as the end-Guadalupian extinction event, the Guadalupian-Lopingian boundary mass extinction, the pre-Lopingian crisis, or the Middle Permian extinction) was a major mass extinction event that occu ...

. The Guadalupian is also known as the Middle Permian.

Name and background

The Guadalupian is the second and middle series or epoch of the Permian. Previously called Middle Permian, the name of this epoch is part of a revision of Permian stratigraphy for standard global correlation. The name "Guadalupian" was first proposed in the early 1900s, and approved by the International Subcommission on Permian Stratigraphy in 1996. References to the Middle Permian still exist. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains in New Mexico. The International Chronostratigraphic Chart V2021/07 provides a numerical age of 273.01 ± 0.14 – 259.51 ± 0.21 mya.

Biodiversity

Therapsids became the dominant land animals in Guadalupian, displacing the

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 ...

s. Therapsids evolved from a group of pelycosaurs called sphenacodonts. Therapsida consists of four major

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

: the

dinocephalia Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. ...

ns, the herbivorous

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 ...

s, the carnivorous

biarmosuchia Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly built carnivores, intermediate in form between basal sphenacodont " pel ...

ns, and the mostly carnivorous

theriodont The theriodonts (clade Theriodontia) are a major group of therapsids which appeared during the Middle Permian and which includes the gorgonopsians and the eutheriodonts, itself including the therocephalians and the cynodonts. Naming In 1876, ...

s. After a brief burst of evolutionary diversity, the dinocephalians died out in the later Guadalupian. Titanophoneus chart2 DB15

occurred in the early Guadalupian before the larger

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 ...

. This extinction was originally called Olson's Gap because it was thought to be a problem in preservation of fossils. Since the 1990s it has been renamed

. This extinction event occurred near the beginning of the epoch and led to an extended period of low diversity when two-thirds of terrestrial vertebrate life was lost worldwide. Global diversity rose dramatically by the end 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 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 ...

. There is no agreed cause for the Olson's Extinction.

Climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

may be a possible cause. Extreme environments were observed from the Permian of Kansas which resulted from a combination of hot climate and acidic waters particularly coincident with Olson's Extinction. Whether this climate change was a result of Earth's natural processes or exacerbated by another event is unknown.

Climate

The climate resembled that of much of central Asia today.

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 ...

was a supercontinent and had very hot dry summers and cold bitter winters. At this time on the equator there was a desert that reached 74 degrees Celsius. The coasts were tropical and had monsoons. The first two-thirds of the epoch were the continuation of a temperate and tropical climate. This started to dry out and the coal forming of the previous epoch stopped. The change in climate also provided a new environment for new tetrapods, reptiles, fish, plants, and invertebrates. In the last third the temperature started to drop and many coral reefs died out. If that was not enough, increased volcano activity brought a reduction in oxygen, a greenhouse and mass extinction.

Subdivisions

There are three stages in the guadalupian, they are the

Roadian In the geologic timescale, the Roadian is an age or stage of the Permian. It is the earliest or lower of three subdivisions of the Guadalupian Epoch or Series. The Roadian lasted between and million years ago (Ma). It was preceded by the Kun ...

Wordian In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian Epoch or Series. The Wordian lasted between and million years ago (Ma). It was preceded by the Roadian and fo ...

, and

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 ...

Roadian

The

Stage was between 272.3 ± 0.5 – 268.8 ± 0.5 Mya.

was a worldwide loss of terrestrial vertebrate life that occurred during the Roadian and Wordian. Fauna did not recover fully from Olson's Extinction before the impact of the Permian-Triassic extinction event. Estimates of recovery time vary, where some authors indicated recovery was prolonged, lasting 30 million years into the Triassic. Several important events took place during Olson's Extinction, most notably the origin of

therapsids Therapsida is a clade comprising a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including li ...

, a group that includes the evolutionary ancestors of mammals. Further research on the recently identified primitive therapsid of the Xidagou Formation (Dashankou locality) in China of Roadian age may provide more information on this topic.

Wordian

The

Stage was between 268.8 ± 0.5 – 265.1 ± 0.4 Mya. The base of the Wordian Stage is defined as the place in the stratigraphic record where fossils of

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 ''

Jinogondolella ''Jinogondolella'' is an extinct genus of conodonts. Mesogondolella and Jinogondolella (Conodonta): Multielement definition of the taxa that bracket the basal Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/ ...

aserrata'' first appear. The global reference profile for this stratigraphic boundary is located at Getaway Ledge in the

. The top of the Wordian (the base of the Capitanian Stage) is defined as the place in the stratigraphic record where the conodont species ''Jinogondolella postserrata'' first appears.

Capitanian

The

Stage was between 265.1 ± 0.4 – 259.8 ± 0.4 Mya. The Guadalupian ended with a deteriorating environment, Greenhouse conditions, and several series of mass-extinctions; both the great dinocephalians, other taxa on land and various invertebrates in the sea. They would be succeeded by new types of therapsids, especially the

gorgonopsia Gorgonopsia (from the Greek Gorgon, a mythological beast, and 'aspect') is an extinct clade of Saber-toothed predator, sabre-toothed therapsids from the Middle Permian, Middle to the Upper Permian, roughly between 270 and 252 million years ago. ...

ns among others. A significant mass extinction event (the

End-Capitanian extinction event The Capitanian mass extinction event (also known as the end-Guadalupian extinction event, the Guadalupian-Lopingian boundary mass extinction, the pre-Lopingian crisis, or the Middle Permian extinction) was a major mass extinction event that occu ...

) occurred at the end of this epoch, which was associated with anoxia 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

that followed about 10 million years later.

Carbon isotope Carbon (6C) has 14 known isotopes, from to as well as , of which only and are stable. The longest-lived radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature, as trace quantities are formed ...

s in marine

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

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 () 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 ...

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 tra ...

corals, and Waagenophyllidae.

Other subdivisions

Subdivisions that are sometimes used are, :* Kazanian or Maokovian (in Europe) 70.6 ± 0.7 – 260.4 ± 0.7 Myaref> :* Braxtonian (in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

) 70.6 ± 0.7 – 260.4 ± 0.7 Mya

References

{{Geological history of Earth, p, m Geological epochs *02