Tournaisian

The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 358.9 ± 0.4 Ma to 346.7 ± 0.4 Ma. It is preceded by the Famennian (the uppermost stage of the Devonian) and is followed by the Viséan.