A quantitative palaeobiogeographical analysis on the distribution of Sterlitamakian-Aktastinian (Early Permian) western Pacific brachiopod faunas

A presence/absence data matrix of 183 genera from 29 faunal stations (selected from 33 initially compiled faunal stations on the basis of sampling and study adequacies) is analysed by cluster analysis, nonmetric multidimensional scaling, principal coordinate analysis and minimum spanning tree. Five core faunal groups are revealed and interpreted as representing five biotic provinces. They are the Verkolyma Province embracing the Kolyma Massif, Verchoyan Mountains, east Zabaikal, central north Mongolia, Inner Mongolia and the Sikhote Alin terrane; the Cathaysian Province of the Yangtze block, North China block, the Tarim Basin and the Kitakami Masssif; an incipient Cimmerian Province composed of western peninsular Malaysia and south Thailand; the Westralian Province of the Western Australian intracratonic basins, Timor, Irian Jaya, peninsular India, the Himalaya, Lhasa terrane, western Qiangtang block and the Baoshan block; and the Austrazean Province of eastern Australia and New Zealand. The palaeogeographical implications of the provincial patterns recognised are discussed and a modified version of Sterlitamakian-Aktastinian western Pacific palaeogeography is presented.