|Subdivision of the Neogene Period|
according to the ICS, as of 2017.
The Serravallian is in the geologic timescale an age or a stage in the middle Miocene epoch/series, that spans the time between 13.65 ± 0.05 Ma and 11.608 ± 0.005 Ma (million years ago). The Serravallian follows the Langhian and is followed by the Tortonian.
It overlaps with the middle of the Astaracian European Land Mammal Mega Zone, the upper Barstovian and lower Clarendonian North American Land Mammal Ages and the Laventan and lower Mayoan South American Land Mammal Ages. It is also coeval with the Sarmatian and upper Badenian stages of the Paratethys time scale of Central and eastern Europe.
The base of the Serravallian is at the first occurrence of fossils of the nanoplankton species Sphenolithus heteromorphus and is located in the magnetic chronozone C5ABr. The official Global Boundary Stratotype Section and Point (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 nannoplanktons Discoaster kugleri and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal-polarized magnetic chronozone C5r.2n. It was about 13 million years ago when the possible common ancestor of humans and other bipedal apes, Pierolapithecus, first began to drag their knuckles and walk upright in modern-day Spain.
- "Tinescale Chart". www.stratigraphy.org.
- Gradstein et al. (2004)
- Lorenzo Pareto, Note sur les subdivisions que l'on pourrait établir dans les terrains tertaires de l'Apennin septentrional In Bulletin de la Société Géologique de France, volume 22, série 2, pp. 210-277
|Wikisource has original works on the topic: Cenozoic#Neogene|
- Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Pareto, L.; 1865: Note sur la subdivision que l'on pourrait etablir dans les terrains de l'Apennin septentrional, Bulletin de la Societé Géologique de France 2(22), p. 210-277. (in French)