Analyse of acritarch assemblages at the Tremadocian-Arenigian boundary
Abstract
The world-wide spatial distribution of selected upper "Tremadocian" and lower "Arenigian" acritarch taxa is analysed. The database consists of more or less comprehensive lists of taxa available from Gondwana, peri-Gondwana, South China, Baltica, North China, while spotty data come from Laurentia, and Australia. The data are plotted on the recent palaeogeographic map. The pattern of distribution of the acritarch taxa shows an obvious relation between composition of acritarch assemblages and their palaeolatitudinal position. Five taxa are limited on the polar and subpolar areas, other six forms are typical for the subpolar and temerate areas, while there genera occur in the tropical areas only.