Ordovizische Spongien aus dem Anstehenden in Estland und der St. Petersburg-Region verglichen mit erratischen Spongien in Deutschland [Ordovician sponges from strata in Estonia and the St. Petersburg region compared with erratic sponges in Germany]

Ordovician sponge associations from strata of the Haljala Stage (CII-DI) in Estonia and the St. Petersburg region are briefly described. Composition and age show strong similarities with part of the erratic sponge associations, i. c. astylospongiids that were deposited fluvially during Miocene and Pliocene times in northern Germany and the Netherlands, as part of the so called 'blue' sponge assemblage, which is always connected with the erratic assemblage of 'lavenderblue cherts'. In contrast, anthaspidellids, such as Aulocopium aurantium, which predominate in the erratic assemblages, are nearly absent in those from Baltic strata. The species Carpospongia langei von HACHT, 1994 is invalid since it is a junior synonym of C. pogrebowi ASATKIN, 1949. Suggestions for future investigations are presented in the end.