The Serravallian is, 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 geochr ...

, an age or a

stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

in the middle

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

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 ...

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 in ...

, which spans the time between 13.82 Ma and 11.63 Ma (million years ago). The Serravallian follows the

Langhian The Langhian is, in the International Commission on Stratigraphy, ICS geologic timescale, an age (geology), age or stage (stratigraphy), stage in the middle Miocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between 15 ...

and is followed by the

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Torto ...

. It overlaps with the middle of the

Astaracian The Astaracian age is a period of geologic time (), equivalent with the Middle Miocene and used more specifically with European Land Mammal Ages. It precedes the Vallesian age and follows the Orleanian age. The Astaracian overlaps the Langhian and ...

European Land Mammal Mega Zone The European Land Mammal Mega Zones (abbreviation: ELMMZ, more commonly known as European land mammal ages or ELMA) are zones in rock layers that have a specific assemblage of fossils (biozones) based on occurrences of fossil assemblages of Europe ...

, the upper Barstovian and lower

Clarendonian The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 13,600,000 to 10,300,000 years BP, a period of . It is ...

North American Land Mammal Ages and the

Laventan The Laventan ( es, Laventense) age is a period of geologic time (13.8 to 11.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Colloncuran and precedes th ...

and lower

Mayoan The Mayoan ( es, Mayoense) age is a period of geologic time from 11.8 to 10 Ma, within the Middle to Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Laventan and precedes ...

South American Land Mammal Ages The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...

. It is also coeval with the Sarmatian and upper Badenian Stages of the Paratethys time scale of Central and eastern Europe.

Definition

The Serravallian Stage was introduced in stratigraphy by the

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

geologist

Lorenzo Pareto Lorenzo Nicolò Pareto ( Genoa, 6 December 1800 – Genoa, 19 June 1865) was an Italian geologist and statesman. As a man of science, he is considered one of the fathers of modern geology. A member of the Italian National Academy of Sciences, ...

in 1865. It was named after the town of

Serravalle Scrivia Serravalle Scrivia is a ''comune'' (municipality) in the Province of Alessandria in the Italian region of Piedmont, located about southeast of Turin and about southeast of Alessandria. Serravalle Scrivia borders the following municipalities: Ar ...

in northern Italy. The base of the Serravallian is at the first occurrence of fossils of the

nanoplankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...

species '' Sphenolithus heteromorphus'' and is located in the chronozone C5ABr. The official

Global Boundary Stratotype Section and Point 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 ...

(GSSP) for the Serravallian is in the 'Ras il-Pellegrin' section, located at the 'Ras il-Pellegrin' headland in the vicinity of 'Fomm ir-Rih' Bay, SW Malta.The base of the Serravallian is represented in the field as the formation boundary between the Globigerina Limestone formation and the Blue Clay formation. The base of the Serravallian is related to the Mi3b oxygen isotope excursion marking the onset of the Middle Miocene Cooling step. The top of the Serravallian (the base of the Tortonian Stage) is at the last common appearance of calcareous nanoplanktons '' Discoaster kugleri'' and planktonic

foram Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly a ...

'' Globigerinoides subquadratus''. It is also associated with the short normal-polarized chronozone C5r.2n.

Paleontology

Cartilaginous fish

Lamniformes The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the grea ...

Otodontidae Otodontidae is an extinct family of sharks belonging to the order Lamniformes. Its members have been described as megatoothed sharks. They lived from the Early Cretaceous to the Pliocene, and included genera such as ''Carcharocles'' and ''Otod ...

: †''

Otodus ''Otodus'' is an extinct genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name ''Otodus'' comes from Ancient Greek (, meaning "ear") and (, meaning "tooth") – thus, "ear-shaped tooth". Anatomy This shark is ...

Birds

* Anseriformes **

Anatidae The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating ...

: '' Clangula sp.''

Mammals

* Primates ** Hominidae: †'' Anoiapithecus''.

Reptiles

Squamata Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species ...

** Agamidae: ''

Pogona ''Pogona'' is a genus of reptiles containing six lizard species which are often known by the common name bearded dragons. The name "bearded dragon" refers to the underside of the throat (or "beard") of the lizard, which can turn black and gain we ...

'' and ''

Diporiphora ''Diporiphora'' is a genus of lizards in the family Agamidae. Most species in the genus are endemic to Australia, but two (''D. australis'' and ''D. bilineata'') are also found in New Guinea. Species The genus includes these 28 species wh ...

'' diverged from their last common ancestor during the Serravallian. *

Crocodylomorpha Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. During Mesozoic and early Cenozoic times, cro ...

**The last known

sebecid Sebecidae is an extinct family of prehistoric terrestrial sebecosuchian crocodylomorphs. The oldest known member of the group is ''Ogresuchus furatus'' known from the Upper Cretaceous (Maastrichtian) Tremp Formation (Spain). Sebecids were di ...

, ''

Barinasuchus ''Barinasuchus'' (meaning " Barinas crocodile," in reference to where the type material was found) is an extinct genus of sebecid mesoeucrocodylian. Its fossils have been found in middle Eocene-age rocks of the Divisadero Largo Formation of Arg ...

'', goes extinct about 11.8 mya. Thus ending the lineage of the

notosuchians Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group (see below); if S ...

References

Notes

Literature

*; 2004: ''A Geologic Time Scale 2004'',

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209 and granted a royal charter by Henry III of England, Henry III in 1231, Cambridge is the world' ...

Press. *; 1865: ''Note sur la subdivision que l'on pourrait etablir dans les terrains de l'Apennin septentrional'', Bulletin de la Société Géologique de France 2(22), p. 210-277.

External links

GeoWhen Database - SerravallianNeogene timescale
at the website of the subcommission for stratigraphic information of the ICS
Neogene timescale
at the website of the Norwegian network of offshore records of geology and stratigraphy {{Geological history, p, c *04 Miocene geochronology Geological ages