Discoceras fossils are relatively common in ordovician erratics (“Macrouruskalk”) of Northern Germany. In most cases however, their remains are incomplete, more or less crushed and/or badly preserved. In contrast, complete and well-preserved specimens are very rare. The piece presented here is an absolute exception. The preservation is very good and even the living chamber is largely intact.

The preparation of these Ordovician nautiloid fossils is difficult, because the limestone is not only very hard, but also has very poor separation. In addition, the shell is almost always partly dissolved and therefore very fragile. When all parts of the fossil are carefully collected and the preparation is done with patience and caution, extremely attractive results like this one can be achieved.

Fossil: Discoceras danckelmanni (REMELÉ, 1890)

Locality: Cliff near Rerik (Germany)

Formation: Middle Ordovician, Macrouruskalk

Diameter: 11cm (4.3 inch)

Work required: 18 hours

Collection: Jan Tädcke

This Discoceras and its preparation process were presented in 2019 at the 18th conference for “Geschiebeforschung” (glacial erratics research) in the Natural History Museum Berlin:

Paul Freitag & Jan Tädcke: Vom Fund zum fertigen Ausstellungsstück: Porträt eines Discoceras aus einem Macrouruskalk-Geschiebe. Link zur Tagung: https://www.geschiebekunde.de/02-11-bis-03-11-2019-18-berliner-tagung-fuer-geschiebeforschung/