Work on the distribution of Permian faunas and floras has suggested to several palaeontologists (Stehli, 1971; Chaloner and Lacey, 1973; Yancey, 1975) that the variations found in the biotas from various parts of the world can be best explained by the existence of a marked thermal gradient between equatorial and polar regions. There were also geographical variations within the equatorial belt, as there were in the Carboniferous, enabling several faunal provinces to be distinguished. These are shown especially well by the fusulinid foraminiferida (Ross, 1967).The Eurasian/Boreal province, covering most of Asia, eastern Europe and the Arctic area (including northern Canada) is characterised by foraminifera such as Quasifusulina and Schwagerina, and brachiopods including Horri-donia and Licharewia. There was also a Cordilleran Province and a mid-Continent/South American province, each with characteristic faunas. Although there was a cosmopolitan element in most Permian faunas (e.g. Pseudoschwagerina) most areas also contain their own characteristic species. The explanation for the distribution of these faunas, and the communities which provide the data for such conclusions, appears to be the combination of the above-mentioned thermal gradient, the winds, and the ocean currents, as in the earlier Carboniferous.
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