"Mosses, lycopods, sphenopsids, ferns, seed ferns and cordaites." The next part of the description we have of the Pennsylvanian is a laundry list of plant kinds which sounds like an ecosystem or habitat, not a period of time.
"Mosses, lycopods, sphenopsids, ferns, seed ferns and cordaites." The next part of the description we have of the Pennsylvanian is a laundry list of plant kinds which sounds like an ecosystem or habitat, not a period of time.