Grote clausilia (Balea biplicata), Aardschijfje (Lucilla scintilla) en Genaveld tonnetje (Lauria cylindracea) als nieuwe vondsten op de Sint-Pietersberg bij Maastricht: drie verschillende verklaringen?

In 1987 we adopted Balea biplicata biplicata as a new inhabitant of Mount Saint Peter, a cretaceous hill south of Maastricht. In 2006 for the first time on this hill we found in soil samples Lucilla scintilla and Lauria cylindracea cylindracea. We speculate on different mechanisms that may have accounted for these additions to the malacofauna of this hill, including unintentional introduction, transportation from a nearby site, and unusual collection of soil samples.