This large nautilid of the genus Paracenoceras impresses not only through its good preservation, but also through its extreme overgrowth. Several bivalves of different species have settled on the shell next to numerous serpulids. The overgrown bivalve in the centre testifies that this overgrowth even started during the lifetime of the nautilid.

The preparation proved to be extremely painstaking especially because of the extreme overgrowth and could only be mastered by using fine air abrasives and a lot of patience. The rock consisted partly of marly or weathered areas, which alternated, however, with much harder parts. Since it was hard to predict where the next serpulid or shell would appear, progress in the preparation was slow. In the end, the preservation of all the fossils that lived on the nautilid was more than worth it – the shell of the nautilid provided space for many other individuals and is thus an impressive example of the biodiversity of the French Jurassic from the Falaises des Vaches Noire.

Fossil: Paracenoceras giganteum D’ORBIGNY 1842 with Modiolus bipartitus SOWERBY 1818, Liostrea sp. and Serpulids

Locality: Coast between Villers-sur-Mer and Houlgate, Falaises des Vaches Noires (France)

Formation: Jurassic,  middle Oxfordian

Diameter: about 29 cm, (11,4 inches)

Work required: 32 hours

Collection: Dana Räder