REORGANIZATION OF MARINE BIOTA DURING THE MID-EARLY PERMIAN EPOCH

Abstract

The evolution history of fusulinids, brachiopods, ammonoids, and conodonts shows that while advancing across the Sakmarian-Artinskian boundary, all these faunal groups suffered a crisis that was followed by a peak of their speciation during the Kungurian (Bolorian) Stage. The regenerated Artinskian-Kungurian biota differs from that of the Asselian-Sakmarian time by a higher taxonomic diversity, and by the first appearance of the Late Permian elements. The critical moment coincides with a period of global regression, while the active development of rejuvenated biota and its expansion correspond to the transgression stage. The climatic changes were evidently another important factor, which affected the evolutionary trend of the studied fossils. Copyright © 1996 by MAEe cyrillic signK Hayκa/Interperiodica Publishing.