Wuchiapingian (early Lopingian, Permian) global brachiopod palaeobiogeography: a quantitative approach

A global presence/absence database of 212 Wuchiapingian (early Lopingian, P ermian) brachiopod genera from 30 stations is analysed by cluster analysis, nonmetric multidimensional scaling and minimum spanning tree to document t he global palaeobiogeographical patterns. Five core groups an revealed by t he quantitative analysis and interpreted as representing five marine biotic provinces. They are the Cathaysian (tropical), Western Tethyan (tropical), Himalayan (warm temperate), Austrazean (cold temperate) and Greenland-Sval bard Provinces (cold temperate). The Cathaysian Province is composed of man y isolated or semi-isolated islands situated in the Palaeotethys, whereas t he other four provinces occurred mainly on the continental shelves of Pange a: the Western Tethyan Province along the western coast of the Palaeotethys , the Himalayan Province on the northern margin of Gondwanaland, the Austra zean Province along the southeastern margin of Gondwanaland, and the Greenl and-Svalbard Province on the northern margin of Pangea. In addition, nonmet ric multidimensional scaling helped to identify key biogeographic determina nts: latitude-related thermal gradient appears to have accounted for most o f the variance in the data; geographic distance and ocean circulation may h ave also played a major, but subordinate, role in the delineation and/or en hancement of some of the provinces. Comparison with Early and Middle Permia n global marine provincialism indicates that marine biotic provinces had si gnificantly reduced during the Lopingian (Late Permian) in the lead up to t he end-Permian mass extinction. (C) 2000 Elsevier Science B.V. All rights r eserved.