ABSTRACT
Brachiopod species diversity in the Frasnian of southern Poland reveals that the fauna was most diversified in the early part of the stage. Following this, diversity gradually decreased, reaching a minimum just above the Frasnian-Famennian boundary. Recovery started in the late P. triangularis Chron. During the P. crepida Chron, surviving brachiopods seem to have fully recovered, reaching highest taxonomic diversification for the Famennian. The same data plotted as turnover rates show a sharp negative pulse expressing high extinction rates, and very low numbers of newly originating species. The second negative turnover pulse occurred during the later part of the P. crepida to P. rhomboidea chrons. This event was associated with strong regression in the basin, and migration of the brachiopod fauna out of the area. Co-occurring conodonts reveal a similar pattern of evolutionary dynamic.
