Type
Zone
Age range
259–258.5 Ma
Lopingian
Wuchiapingian
Clarkina asymmetrica
Clarkina dukouensis
Clarkina postitteri postitteri
259.02259.00258.98258.96258.94258.92258.90258.88258.86258.84258.82258.80258.78258.76258.74258.72258.70258.68258.66258.64258.62258.60258.58258.56258.54258.52258.50258.48