Type
Zone
Age range
298–297.5 Ma
Cisuralian
Asselian
Streptognathodus constrictus-Mesogondolella belladontae
Streptognathodus sigmoidalis-Streptognathodus cristellaris
Streptognathodus isolatus
298.02298.00297.98297.96297.94297.92297.90297.88297.86297.84297.82297.80297.78297.76297.74297.72297.70297.68297.66297.64297.62297.60297.58297.56297.54297.52297.50297.48