Pridoli
Period
In the geologic timescale, the Přídolí Epoch is the uppermost subdivision of the Silurian Period, dated at between 423 ± 2.3 and 419.2 ± 3.2 mya. The Přídolí Epoch succeeds the Ludfordian Stage and precedes the Lochkovian, the lowest of three... Wikipedia
Period: Silurian
Occurred: 423 (+/- 2.3) million years ago - 419.2 (+/- 3.2) million years ago
Lower GSSP ratified: 1984
Upper boundary definition: FAD of the graptolite Monograptus uniformis
Upper boundary GSSP: Klonk, Prague, Czech Republic; 49°51′18″N 13°47′31″E / 49.8550°N 13.7920°E
Upper GSSP ratified: 1972