Pennsylvanian
The rainforest system collapsed about halfway through the Pennsylvanian, and was replaced by a cooler, drier climate. The wetland forests ended when the land level was raised by the pressure of the Gondwana continent against Laurussia, causing the zone of contact to be raised. The end of the Coal Measures marks the end of the Carboniferous period. China was too far away to be affected, and there the wetland forests continued for another 50 million years, into the early Permian.p30