Type
Zone
Age range
294.1–293.5 Ma
Cisuralian
Sakmarian
Asselian
Sweetognathus anceps-Mesogondolella bisselli
Sweetognathus binodosus
Sweetognathus merrilli-Mesogondolella uralensis
294.10294.05294.00293.95293.90293.85293.80293.75293.70293.65293.60293.55293.50