Weathered Fossiliferous Nodule / Crinoid Fragment
Indeterminate crinoid cf. Columnar fragment • Body fossil (Invertebrate fragment within a mineralized nodule)
Geological Period
Possibly Carboniferous to Permian
Estimated Age
250 to 350 million years
Preservation Type
Permineralization and replacement with significant abrasive weathering (water-worn)
Condition Assessment
Poor to Fair; significant erosion has removed most diagnostic anatomical features, leaving only ghosts of the original structures
Taxonomic Classification
Phylum: Echinodermata; Class: Crinoidea (likely)
Morphological Description
The specimen is a rounded, heavily weathered nodule. One side shows recessed pits and circular imprints consistent with crinoid columnals (sea lily stems). The surface is rugose with granular textures and iron staining.
Rock Matrix
Siliceous limestone or iron-rich siltstone with possible chert inclusions
Formation & Location
Likely sourced from a riverbed or glacial till; common in various Paleozoic formations in the Midwestern United States or UK Pennines
Size & Dimensions
Approximately 3-5 cm in diameter; small for a geological nodule, average for weathered Paleozoic debris
Value & Rarity
Estimated Market Value
$1 - $5 USD
Auction Estimate
$0 - $5 (Typically not suitable for professional auction)
Rarity Assessment
Common; such weathered fragments are ubiquitous in high-energy sedimentary deposits of Paleozoic age
Scientific Significance
Low; provides evidence of benthic marine life in a Paleozoic sea but lacks the structural integrity for detailed taxonomic study
Preparation Recommendations
No further mechanical preparation advised as the specimen is heavily worn. Store in a dry environment and keep as a representative 'field find' or educational sample.
Notable Features
The specimen's rounded shape suggests a long history of fluvial transport, effectively acting as a 'river stone' that reveals its fossil content only through surface erosion.