The Campanian is the fifth of six

ages Ages may refer to: *Advanced glycation end-products, known as AGEs *Ages, Kentucky, census-designated place, United States * ''Ages'' (album) by German electronic musician Edgar Froese *The geologic time scale, a system of chronological measuremen ...

of the Late Cretaceous Epoch on 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 geochronol ...

of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six

stages 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 * S ...

in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...

and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks.

Etymology

The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of

Aubeterre-sur-Dronne Aubeterre-sur-Dronne (, literally ''Aubeterre on Dronne''; oc, Aubaterra or ''Aubaterra de Drona''), commonly referred to as Aubeterre, is a commune in the Charente department in the Nouvelle-Aquitaine region of Southwestern France. In 2017, it h ...

in the same region.

Definition

The base of the Campanian Stage is defined as a place in the stratigraphic column where the extinction of crinoid species ''

Marsupites ''Marsupites'' is an extinct genus of crinoids from the Santonian stage of the Late Cretaceous.Global Boundary Stratotype Section and Point or GSSP had not yet been ratified as of 2009: one possible candidate is a section near a dam at Waxahachie, Texas.) The top of the Campanian stage is defined as the place in the stratigraphic column where the

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

'' Pachydiscus neubergicus'' first appears.

Subdivisions

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 ammonite '' Baculites obtusus'' (80.97 Ma) and the base of the Upper Campanian defined as the first occurrence of the ammonite '' Didymoceras nebrascense.'' (76.27 Ma) In the Tethys domain, the Campanian encompasses six ammonite biozones. They are, from young to old: * zone of '' Nostoceras hyatti'' * zone of ''

Didymoceras ''Didymoceras'' is an extinct genus of ammonite cephalopod from the Late Cretaceous epoch (approximately 76 Ma). It is one of the most bizarrely shaped genera, with a shell that spirals upwards into a loose, hooked tip. It is thought to have drif ...

chayennense'' * zone of '' Bostrychoceras polyplocum'' * zone of '' Hoplitoplacenticeras marroti'' / ''Hoplitoplacenticeras vari'' * zone of '' Delawarella delawarensis'' * zone of ''

Placenticeras ''Placenticeras'' is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America. Taxonomy ''Placenticeras'', named by Fielding Bradford Meek, 1870, is the type genus for the Placenticerat ...

bidorsatum''

Paleontology

During the Campanian age, a

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

among dinosaur species occurred. In North America, for example, the number of known dinosaur

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

rises from 4 at the base of the Campanian to 48 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.See Weishampel ''et al.'' (2004)

References

External links

GeoWhen Database – Campanian

Late Cretaceous timescale
at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Late Cretaceous
at the website of Norges Network of offshore records of geology and stratigraphy
Campanian Microfossils: 75+ images of Foraminifera
{{Geological history, p, m *05 Geological ages Cretaceous geochronology