Prehistoric life
At the end of the Carboniferous, shallow seas drained away leaving broad coastal plains covered in swampy forests in their stead. These lasted right through until the Permian period. Their vegetation was dense and lush and had evolved to cope with the shifting courses of rivers and the appearance and silting up of lakes. The coal forests resembled our flooded prone rainforests, mangrove swamps and cypress swamps, although the actual plants were quite different - dominated by giant relatives of horsetails and club mosses. When leaves, branches and whole trees toppled into the water, instead of decaying away they formed a layer of peat that would eventually become coal.
In order to see this content you need to have an up-to-date version of Flash installed and Javascript turned on.
Humid history
Fossil trees tell of a time when Britain was covered in tropical rainforest.
Fossil trees tell of a time when Britain was covered in tropical rainforest.
Tropical swampland
Carboniferous Wales was dominated by giant versions of today's tiny club mosses.
Carboniferous Wales was dominated by giant versions of today's tiny club mosses.
Coal plants
Vast carbon deposits from the giant plants of Wales' tropical forests formed today's coal fields.
Vast carbon deposits from the giant plants of Wales' tropical forests formed today's coal fields.
Coal forests were the vast swathes of wetlands that extended over much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times. As vegetable matter from these forests decayed, enormous deposits of peat accumulated, which later changed into coal.
Much of the carbon in the peat deposits produced by coal forests came from the photosynthetic splitting of existing carbon dioxide, which released the accompanying split-off oxygen went into the atmosphere. This process may have greatly increased the oxygen level, possibly as high as about 35 percent, making the air more breathable for animals, as indicated by the size of Meganeura compared to modern dragonflies.[citation needed]
Coal forests covered tropical Euramerica (Europe, eastern North America, northwesternmost Africa) and Cathaysia (mainly China). Climate change devastated these tropical rainforests during the Carboniferous Period. The Carboniferous Rainforest Collapse was caused by a cooler, drier climate that initially fragmented, then collapsed the rainforest ecosystem. During most of the rest of Carboniferous times, the coal forests were mainly restricted to refugia in North America (such as the Appalachian and Illinois coal basins) and central Europe.
At the very end of the Carboniferous period, the coal forests underwent a resurgence, expanding mainly in eastern Asia, notably China; they never recovered fully in Euramerica. The Chinese coal forests continued to flourish well into Permian times. This resurgence of the coal forests in very late Carboniferous times seems to have coincided with a lowering of global temperatures and a return of extensive polar ice in southern Gondwana, perhaps due to lessening of the greenhouse effect as the massive coal deposition process abstracted carbon dioxide from the atmosphere.
This entry is from Wikipedia, the user-contributed encyclopedia. If you find the content in the 'About' section factually incorrect, defamatory or highly offensive you can edit this article at Wikipedia. For more information on our use of Wikipedia please read our FAQ.
BBC © 2013 The BBC is not responsible for the content of external sites. Read more.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.
Sea scorpions
Synapsids
