| Campanian | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 83.6 ± 0.2 – 72.2 ± 0.2Ma | |||||||||
| Chronology | |||||||||
| |||||||||
| Etymology | |||||||||
| Name formality | Formal | ||||||||
| Usage information | |||||||||
| Celestial body | Earth | ||||||||
| Regional usage | Global (ICS) | ||||||||
| Time scale(s) used | ICS Time Scale | ||||||||
| Definition | |||||||||
| Chronological unit | Age | ||||||||
| Stratigraphic unit | Stage | ||||||||
| Time span formality | Formal | ||||||||
| Lower boundary definition | Base ofChron C33r[2] | ||||||||
| Lower boundary GSSP | Bottaccione,Gubbio,Italy[2] 43°21′46″N12°34′58″E / 43.3627°N 12.5828°E /43.3627; 12.5828[3] | ||||||||
| Lower GSSP ratified | October 2022[4] | ||||||||
| Upper boundary definition | Mean of 12 biostratigraphic criteria | ||||||||
| Upper boundary GSSP | Grande Carrière quarry,Landes,France 43°40′46″N1°06′48″W / 43.6795°N 1.1133°W /43.6795; -1.1133 | ||||||||
| Upper GSSP ratified | February 2001[5] | ||||||||
TheCampanian is the fifth of sixages of theLate Cretaceousepoch on thegeologic timescale of theInternational Commission on Stratigraphy (ICS). Inchronostratigraphy, it is the fifth of sixstages in theUpper CretaceousSeries. Campanian spans the time from 83.6 (± 0.2) to 72.2 (± 0.2) million years ago. It is preceded by theSantonian and it is followed by theMaastrichtian.[6]
The Campanian was an age when a worldwidesea level rise covered many coastal areas. Themorphology of some of these areas has been preserved: it is anunconformity beneath a cover of marinesedimentary rocks.[7][8]
The Campanian was introduced in scientific literature byHenri Coquand in 1857. It is named after the French village ofChampagne in the department ofCharente-Maritime. The originaltype locality was a series ofoutcrops near the village ofAubeterre-sur-Dronne in the same region.[9]
The base of the Campanian Stage is defined as a place in the stratigraphic column where theextinction ofcrinoid speciesMarsupites testudinarius is located. AGSSP was ratified for the base of the Campanian in October 2022, having been placed in Bottaccione,Gubbio,Italy.[2] The top of the Campanian stage is defined as the place in the stratigraphic column where theammonitePachydiscus neubergicus first appears.[5]
The Campanian can be subdivided into Lower, Middle and Upper Subages. In the western interior of the United States, the base of the Middle Campanian is defined as the first occurrence of the ammoniteBaculites obtusus (80.97 Ma) and the base of the Upper Campanian defined as the first occurrence of the ammoniteDidymoceras nebrascense (76.27 Ma).[10] In theTethys domain, the Campanian encompasses six ammonitebiozones. They are, from young to old:[11]
During the Campanian age, aradiation amongdinosaur species occurred. In North America, for example, the number of known dinosaurgenera rises from four at the base of the Campanian to forty-eight in the upper part. This development is sometimes referred to as the "Campanian Explosion". However, it is not yet clear if the event is artificial, i.e. the low number of genera in the lower Campanian can be caused by a lower preservation chance for fossils in deposits of that age. The generally warm climates and large continental area covered in shallow sea during the Campanian probably favoured the dinosaurs. In the following Maastrichtian stage, the number of North American dinosaur genera found is 30% less than in the upper Campanian.[12]
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