Mats Eriksson

This paper deals with a diverse fauna of polychaetes possessing jaws (= scolecodonts) from the late Silurian Kopanina Formation of the Prague Basin (Czech Republic). The most common genera are Kettnerites, Oenonites and Pistoprion; the entire collection contains at least 16 genera. This is in stark contrast to the four genera recorded from this region by previous authors. The fauna described shows great similarities with coeval ones reported from the Baltic area (Gotland and Estonia), Siberia, Arctic Canada and the British Isles. These new data thus extend the palaeobiogeographical and palaeolatitudinal distribution of several taxa, particularly at the genus but also the species level. The sampled interval embraces the Kozlowskii event and its effects on the polychaetes are briefly discussed. Although the collections are relatively small, particularly from post-event strata, a faunal reorganisation is apparent. The studied collection enabled the stratigraphical ranges of some taxa, including tretoprionids and possibly polychaeturids, to be extended into the late Ludlow. One new species, "Mochtyella" pragensis, is described.