Algae as depth indicators in the Silurian of the Oslo region

Specimens of Girvanella sp. are described for the first time from the Oslo region, Norway. The specimens discussed here occur in Lower Llandoverian biomicrites in the central part of the Oslo region (Bærum/Asker). The distinct association between Girvanella sp. and other faunal elements in the succession provides important new information on the depth ranges of Lcwer Silurian brachiopod communities.