Fossilized Echinoid Fragment
Echinoidea indet. (likely irregular echinoid fragment) • Body fossil, invertebrate
Geological Period
Cretaceous
Estimated Age
66 to 145 million years
Preservation Type
Silicification and permineralization within a secondary carbonate or silica matrix, showing significant water-worn abrasion
Condition Assessment
Fair, heavily weathered and abraded with loss of surface ornamentation and incomplete peripheral margins
Taxonomic Classification
Phylum Echinodermata, Class Echinoidea
Morphological Description
Small, worn, rounded nodule exhibiting faint bilateral or radial symmetry contours under high magnification, though heavily abraded with smoothed surface features obscuring fine ambulacral or interambulacral plating details.
Rock Matrix
Silicified limestone / calcarenite with microcrystalline quartz replacement
Formation & Location
Commonly found in Cretaceous chalk and limestone formations globally, such as the Austin Chalk or European chalk deposits
Size & Dimensions
Approximately 15mm by 10mm by 8mm, falling within the smaller fragment size range for typical echinoid tests
Value & Rarity
Estimated Market Value
5 to 15 USD
Auction Estimate
Not typically suitable for commercial auction due to low monetary value
Rarity Assessment
Common, widely distributed globally in marine sedimentary deposits of the Mesozoic and Cenozoic eras
Scientific Significance
Provides local paleoecological data on shallow marine Cretaceous benthic communities, though limited due to high wear and lack of diagnostic species-level features
Preparation Recommendations
No aggressive mechanical preparation needed; gentle washing with water and a soft brush to remove surface debris is sufficient, store in a stable dry environment
Notable Features
Demonstrates advanced post-depositional wear and rounding, indicative of transport in a high-energy aquatic or littoral environment prior to final discovery