The study area is a part of the SSE-NNE elongated, asymmetric Korneuburg Basin. This basin is about 20 km long and attains a maximum width of 7 km, but is strongly narrowed in its northern extension (Figure 1). The mascot-fossil of this Miocene basin is clearly the giant oyster Crassostrea gryphoides, which grew up to 80 cm in length (Figure 3).

Figure 3: The oyster shell of Crassostrea gryphoides (Schlotheim, 1813) with a lemon as scale.

The most spectacular finding in the Korneuburg Basin is a large oyster shell bed (Figure 4). About 400m² of that "oyster reef" were excavated during field campaigns of the Natural History Museum Vienna between 2005 and 2008.

Figure 4: The oyster biostrome, comprising more than 15.000 shells during excavation in 2009.

The excavation turned out to present the world’s largest excavated fossil oyster reef which, with support of the federal government, became attraction and geo-edutainment park Fossilienwelt Weinviertel. It is the largest of its kind in Europe with more than 200.000 visitors, and protection from the nature conservation laws of Lower Austria (§12 NÖ Naturschutzgesetz) due to its exceptional scientific importance.

Figure 5: Fossil oyster biostrome (left), sample detail (right)