Crinoid Stem Segment
Crinoid indet. • Body fossil, invertebrate
Geological Period
Carboniferous
Estimated Age
300 to 350 million years
Preservation Type
Permineralization and calcitic replacement
Condition Assessment
Fair to Good. The specimen is moderately complete and articulated along the main axis, showing some surface weathering, breakage at the terminal ends, and partial matrix encrustation.
Taxonomic Classification
Phylum Echinodermata, Class Crinoidea
Morphological Description
Elongated, column-like stem fossil displaying distinct stacked circular to sub-circular columnals with a central axial canal running longitudinally. Radial symmetry and segmented plate patterns are clearly visible along the column.
Rock Matrix
Fine-grained argillaceous limestone and calcareous shale matrix
Formation & Location
Worldwide distribution in Paleozoic marine deposits; commonly found in the Borden Group or similar Mississippian/Pennsylvanian formations
Size & Dimensions
Approximately 10 to 12 cm in length, consistent with medium-sized Paleozoic crinoid column segments
Value & Rarity
Estimated Market Value
15 to 45 USD
Auction Estimate
20 to 50 USD
Rarity Assessment
Common
Scientific Significance
Provides evidence of ancient shallow marine carbonate environments and paleo-ecosystems, contributing to our understanding of Paleozoic benthic community structures.
Preparation Recommendations
Mechanical cleaning using fine pin vices or air abrasive with dolomite powder to remove excess shale matrix. Store in a dry, climate-controlled environment to prevent moisture-induced degradation.
Notable Features
Well-preserved articulation of individual columnals with distinct crenularium patterns visible along the segmented surfaces.