The Pennsylvanian is a subperiod of the Carboniferous period lasting from roughly to Ma (million years ago). As with most other geologic periods, the rock beds that define the period are well identified, but the exact date of the start and end are uncertain by a few million years. The Pennsylvanian is named after the state of Pennsylvania, where rocks from this age are widespread.
In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian is treated as a full fledged geologic period between the Mississippian and the Permian. In Europe, the Mississippian and Pennsylvanian are one more-or-less continuous sequence of lowland continental deposits and are grouped together as the Carboniferous period.
All modern classes of fungi were present in the Late Carboniferous (Pennsylvanian Epoch).