Paleozoic
Carboniferous
Pennsylvanian
Bashkirian
Mississippian
Serpukhovian
Visean
Tournaisian
1.9 Ma
Paleozoic
Carboniferous
Mississippian
Tournaisian
3.4 Ma
Paleozoic
Devonian
Late Devonian
Famennian
22.7 Ma
Paleozoic
Devonian
Middle Devonian
Givetian
Eifelian
Early Devonian
Emsian
Pragian
Lochkovian
Silurian
Pridoli
7.1 Ma
Paleozoic
Silurian
Ludlow
Gorstian
Wenlock
Homerian
Sheinwoodian
Llandovery
Telychian
Aeronian
Rhuddanian
4.4 Ma
Paleozoic
Ordovician
Late Ordovician
Hirnantian
Katian
Sandbian
Middle Ordovician
Darriwilian
6.0 Ma
Paleozoic
Ordovician
Middle Ordovician
Dapingian
Early Ordovician
Floian
Tremadocian
Cambrian
Furongian
Stage 10
Jiangshanian
4.3 Ma
Paleozoic
Cambrian
Series 3
Guzhangian
Drumian
Stage 5
Series 2
Stage 4
839.0 Ma
Mesoproterozoic
Ectasian
Calymmian