'This coal-forming period of geologic time is split into Mississippian & Pennsylvanian periods'
carboniferous
PREHISTORIC TIMES: This coal-forming period of geologic time is split into Mississippian & Pennsylvanian periods
This coal-forming period of geologic time is split into Mississippian & Pennsylvanian periods
This coal-forming period of geologic time is split into Mississippian & Pennsylvanian periods
PREHISTORIC TIMES
carboniferous
PREHISTORIC TIMES