Echinoid spine
Cidaris sp. (isolated spine) • Body fossil, invertebrate
Geological Period
Jurassic to Cretaceous (specifically Late Jurassic / Oxfordian or Cretaceous based on Vaches Noires context)
Estimated Age
160 to 90 million years old
Preservation Type
Calcitic permineralization and fossilization of the original echinoderm stereom structure.
Condition Assessment
Good condition, broken into two distinct segments but showing clear surface ornamentation and minimal wear.
Taxonomic Classification
Phylum Echinodermata, Class Echinoidea, Order Cidaroida, Family Cidaridae
Morphological Description
Elongated, cylindrical spine featuring characteristic longitudinal rows of fine granules or micro-tubercles along the shaft, tapering slightly toward the broken proximal or distal ends.
Rock Matrix
Free of matrix, clean fossil specimen derived from argillaceous or marly marine sediments.
Formation & Location
Falaises des Vaches Noires, Normandy, France (Callovian-Oxfordian and Cretaceous formations)
Size & Dimensions
Approximately 4 to 5 cm in combined length, typical for large cidaroid urchin spines of the Mesozoic.
Value & Rarity
Estimated Market Value
10 to 25 USD
Auction Estimate
5 to 15 USD
Rarity Assessment
Common, frequently found along the Vaches Noires cliffs and similar European Jurassic/Cretaceous deposits.
Scientific Significance
Provides insights into Mesozoic marine benthic ecosystems, specifically the diversity of regular echinoids and their adaptations for defense and locomotion.
Preparation Recommendations
Gentle mechanical cleaning with a soft brush; store in a dry environment to prevent any potential pyrite decay if iron minerals are present.
Notable Features
The distinctive granular or thorny ornamentation running longitudinally down the cylindrical shaft is well-preserved across both fragments.
Notes
falaises des Vaches Noires