Acritarchs and prasinophytes of the Silurian-Devonian GSSP (Klonk, Barrandian area, Czech Republic)

Abstract

At the GSSP for the Silurian-Devonian boundary at Klonk, Czech Republic, a comparatively poorly diversified palynomorph assemblage has been documented. The boundary interval is characterized by the predominance of thick-and/or thin-walled prasinophytes (Leiosphaeridia spp., ?Pleurozonaria spp.), while the other organic-walled microfossil groups are relatively rare (chitonozoans, acritarchs, scolecodonts, certain prasinophytes, mazuelloids). The highest taxonomic diversity of palynomorphs has been documented in the uppermost Přídolí and in the lower part of the Lochkovian. Such a pattern of distribution could be connected with transgressive and regressive pulses occurring at the boundary interval.