A new Late Ordovician erratic anthaspidellid sponge (Porifera) originating from Baltica

The new anthaspidellid taxon Brevaspidella dispersa is erected for specimens recovered from the Late Ordovician sponge assemblages of the island of Gotland, Sweden and the Dutch-German border region. In the latter area, they are collected from Early Pleistocene fluvial deposits of the Baltic River System, whereas those from Gotland are part of Late Pleistocene glacial or fluvio-glacial deposits. The provenance of both assemblages is uncertain, but they probably originated from an Ordovician basin in the northern Baltic Sea or the Bothnian Gulf, west of Finland. As yet, Brevaspidella dispersa gen. et sp. nov. is restricted to the Gotland-German-Dutch sponge association and has not been found in the assemblage of nearly-coeval ‘lavender-blue cherts’ and ‘blue sponges’. The new taxon is closely related to the genus Anthaspidella, but differs in the aquiferous system and in having a well developed concentrically wrinkled dermal layer.