In the Carboniferous period, coal forests, great tropical wetlands, extended over much of Euramerica (Europe and America). This land supported towering lycopsids which fragmented and collapsed abruptly.[11] The collapse of the rainforests during the Carboniferous has been attributed to multiple causes, including climate change.[12] Specifically, at this time climate became cooler and drier, conditions that are not favourable to the growth of rainforests and much of the biodiversity within them.