Mats Eriksson

Genus-level relative frequency changes, based on scolecodont data, show that the polychaete faunas went through dramatic turnovers during the Llandovery-Wenlock Ireviken Event on Gotland. In addition several taxa show range ends (FADs and LADs) and gaps in this interval; at least 20% of the lineages disappeared or became extinct during the event. Datum points 2 and 4 seem to have been particularly harsh. This is the first detailed data set showing the effects of the Ireviken Event on vagrant benthos.