Type
Zone
Age range
395–393.47 Ma
Middle Devonian
Eifelian
Early Devonian
Emsian
Polygnathus costatus partitus
Polygnathus costatus patulus
Linguipolygnathus serotinus
395.0394.9394.8394.7394.6394.5394.4394.3394.2394.1394.0393.9393.8393.7393.6393.5