Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch (or, in chronostratigraphy: the fifth of six stages in the Upper Cretaceous series). The Campanian spans the time from 83.6 ± 0.7 Ma to 72.1 ± 0.6 Ma (million years ago). It is preceded by the Santonian and it is followed by the Maastrichtian.
Campanian
The base of the Campanian stage is laid at the extinction of crinoid species "Marsupites testudinarius". A GSSP had not yet been ratified in 2009. One possible candidate is in a section near a dam at Waxahachie, Texas.