Type
Zone
Age range
393.47–391.5 Ma
Middle Devonian
Eifelian
Early Devonian
Emsian
Polygnathus costatus costatus
Polygnathus costatus partitus
Polygnathus costatus patulus
393.5393.4393.3393.2393.1393.0392.9392.8392.7392.6392.5392.4392.3392.2392.1392.0391.9391.8391.7391.6391.5