Search Result：pennsylvanian period
pennsylvanian period 
(TTS Sound)
(TTS Sound)Overview of noun pennsylvanian_period
The noun pennsylvanian period has 1 sense
- Pennsylvanian, Pennsylvanian period, Upper Carboniferous, Upper Carboniferous period -- (from 310 million to 280 million years ago; warm climate; swampy land)