Kasimovian

The Kasimovian is an geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from 307.0 ± 0.1 to 303.7 ± 0.1 Ma. The Kasimovian stage follows the Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse.