The Capitanian stage was introduced into scientific literature by George Burr Richardson in 1904. The name comes from the Capitan Reef in the Guadalupe Mountains. The Capitanian was first used as a stratigraphic subdivision of the Guadalupian in 1961, when both names were still only used regionally in the southern US. The stage was added to the internationally used ICStimescalein 2001.
Definitions
The base of the Capitanian stage is defined as the place in the stratigraphic record where fossils of conodont species Jinogondolella postserrata first appear. The global reference profile for this stratigraphic boundary is located at Nipple Hill in the southern Guadalupe Mountains of Texas. The top of the Capitanian is defined as the place in the stratigraphic record where the conodont species Clarkina postbitteri postbitteri first appears. The Capitanian stage was part of the time in which the Zechstein was deposited in Europe. It is coeval with the old European regional Saxonian stage. In the eastern Tethys domain, the Capitanian overlaps the regional Murgabian stage, the Midian stage and the lower part of the Laibinian stage. In Russia the Capitanian equals the lower part of the regional Severodvinian stage.
Biostratigraphy
The Capitanian contains one ammonitebiozone and three conodont biozones:
zone of Clarkina postbitteri hongshuiensis
zone of Jinogondolella altudaensis
zone of Jinogondolella postserrata
Larger fusulinid species permit a division in two biozones:
zone of Rausserella
zone of Afganella schenki
Biodiversity
, in the early Guadalupian, led to an extended period of low diversity when worldwide two-thirds of terrestrial vertebrate life was lost. Global diversity rose dramatically in the Capitanian, probably the result of disaster taxa filling empty guilds, only to fall again when the end-Guadalupian event caused a diversity drop in the Wuchiapingian.
Events
s in marinelimestone from the Capitanian age show an increase in δ13C values. The change in carbon isotopes in the sea water reflects cooling of global climates. This climatic cooling may have caused the end-Capitanian extinction event among species that lived in warm water, like larger fusulinids, large bivalves and rugose corals, and Waagenophyllidae.