conodont turnover in the GSSP. A 2012 ICS timescale based on rough radioisotopic records estimated the Famennian began around 372.2 ± 1.6 Ma, and ended at 358.9 ± 0.4 Ma. In 2020 this was revised to a start at 371.1 ± 1.1 Ma and an end at 359.3 ± 0.3 Ma. References See also List of fossil sites (with link directory) Late Devonian Devonian geochronology .