Type
Zone
Age range
85.56–85.23 Ma
Late Cretaceous
Santonian
Desmoscaphites erdmanni
Clioscaphites choteauensis
Clioscaphites vermiformis
85.5685.5485.5285.5085.4885.4685.4485.4285.4085.3885.3685.3485.3285.3085.2885.2685.2485.22