Gastropod steinkern (internal mold)
Gastropoda indet. (likely a large marine snail steinkern such as Pleurotomaria or similar Jurassic taxa) • Internal mold (steinkern), body fossil, invertebrate
Geological Period
Jurassic (Late Jurassic, specifically Oxfordian to Callovian based on the Vaches Noires location)
Estimated Age
160 to 165 million years ago
Preservation Type
Natural internal mold (steinkern) with secondary mineral infill (quartz/calcite crystallization)
Condition Assessment
Fair to Good. Weathered waterworn surface, missing the outer shell layer entirely (preserved only as a steinkern), with some abrasion typical of beach/cliff-fall finds.
Taxonomic Classification
Phylum Mollusca, Class Gastropoda, Order Neogastropoda or Caenogastropoda
Morphological Description
Elongated, spirally coiled internal mold showing deep suture lines and rounded whorls. The aperture and internal structure are not fully visible, but the exterior preserves the cast of the inner whorls with a crystalline quartz/calcite infill visible at the broken end.
Rock Matrix
Glauconitic and calcareous sandstone/marl matrix typical of the coastal deposits
Formation & Location
Falaises des Vaches Noires, Normandy, France (Callovian and Oxfordian formations)
Size & Dimensions
Approximately 3 cm to 4 cm in length, roughly comparable in scale to the adjacent 2-euro coin (25.75 mm diameter)
Value & Rarity
Estimated Market Value
5 to 15 USD
Auction Estimate
10 to 25 USD
Rarity Assessment
Common
Scientific Significance
Provides evidence of shallow marine benthic invertebrate communities during the Jurassic period in the Anglo-Paris Basin.
Preparation Recommendations
Gentle brushing with water to remove loose debris; no aggressive chemical preparation needed as it is a natural steinkern. Store in a dry environment.
Notable Features
Exhibits a sparkling crystalline mineral infill visible at the cross-section/break point of the whorl, adding visual interest to an otherwise standard internal mold.
Notes
falaises des Vaches Noires