Type
Zone
Age range
302–301 Ma
Pennsylvanian
Gzhelian
Streptognathodus simplex-Streptognathodus bellus
Streptognathodus virgilicus
Streptognathodus vitali
302.0301.9301.9301.9301.8301.8301.7301.6301.6301.6301.5301.4301.4301.4301.3301.3301.2301.1301.1301.1301.0