The Furongian is the fourth and final

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 ...

and

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 ...

of the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

. It lasted from to million years ago. It succeeds the

Miaolingian The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018. It lasted from about to million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is prec ...

series of the Cambrian and precedes the

Lower Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The ...

Tremadocian The Tremadocian is the lowest stage of Ordovician. Together with the later Floian Stage it forms the Lower Ordovician Epoch. The Tremadocian lasted from to million years ago. The base of the Tremadocian is defined as the first appearance of the ...

Stage. It is subdivided into three stages: the

Paibian The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian ( 3rd series of the Cambrian) and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite ''Glyptagnostus r ...

Jiangshanian The Jiangshanian is the middle stage of the Furongian series. It follows the Paibian Stage and is succeeded by the still unnamed Stage 10 of the Cambrian. The base is defined as the first appearance of the trilobite ''Agnostotes orientalis'' whic ...

and the unnamed 10th stage of the Cambrian.

Naming

The Furongian was also known as the Cambrian Series 4, and the name replaced the older term Upper Cambrian and equivalent to the local term Hunanian. The present name was ratified by the

International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigra ...

in 2003. () means '

lotus Lotus may refer to: Plants *Lotus (plant), various botanical taxa commonly known as lotus, particularly: ** ''Lotus'' (genus), a genus of terrestrial plants in the family Fabaceae **Lotus flower, a symbolically important aquatic Asian plant also ...

' in Mandarin and refers to

Hunan Hunan (, ; ) is a landlocked province of the People's Republic of China, part of the South Central China region. Located in the middle reaches of the Yangtze watershed, it borders the province-level divisions of Hubei to the north, Jiangxi to ...

which is known as the "lotus state".

Definition

The lower boundary is defined in the same way as the

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 b ...

of the

Stage. Both begin with the

first appearance In American comic books and other stories with a long history, first appearance refers to the first issue to feature a fictional character. These issues are often highly valued by collectors due to their rarity and iconic status. Reader intere ...

of the

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...

Glyptagnostus reticulatus ''Glyptagnostus reticulatus'' is a species of agnostid trilobite belonging to the genus '' Glyptagnostus''. It existed during the Paibian Age ( million years ago) of the Cambrian. It has a cosmopolitan distribution and is an important index fossi ...

'' around million years ago. The upper boundary is the lower boundary and GSSP of the

Stage which is the first appearance of the

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, which ...

Iapetognathus fluctivagus ''Iapetognathus fluctivagus'' is a species of denticulate cordylodan conodonts belonging to the genus '' Iapetognathus''. It existed during the Tremadocian Age ( million years ago) of the Ordovician. It is an important index fossil in biostratig ...

'' around million years ago.

Subdivisions

The following table shows the subdivisions of the Furongian series/epoch:

Biostratigraphy

The base of two of three stages of the Furongian are defined as the first appearance of a trilobite. The base of the Paibian is the first appearance of ''

'' and the base of the

is the first appearance of ''

Agnostotes orientalis ''Agnostotes orientalis'' is a species of agnostid trilobite belonging to the genus '' Agnostotes''. It existed during the Jiangshanian Age ( million years ago) of the Cambrian. It is an important index fossil in biostratigraphy. Description ''A ...

''. The still unnamed

Cambrian Stage 10 Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite '' Lotagnos ...

might be defined as the first appearance of '' Lotagnostus americanus'' or the

Eoconodontus notchpeakensis ''Eoconodontus'' is an extinct genus of conodonts of the Late Cambrian. It is a two-elements (rounded and compressed) genus from the '' Proconodontus'' lineage. Use in stratigraphy It is suggested that ''Eoconodontus notchpeakensis'' can be a ...

''. The Furongian can be divided into a number of

trilobite zone Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The ''Olenellus''-zone has traditionally marked the top of the Lower Cambrian, and is followed by the '' Eokochaspis'' zone. ...

References

*04 Geological epochs {{cambrian-stub