Crinoid Columnal Segment (Sea Lily Stem)
Indeterminate Crinoid sp. (requires cross-section of articulatory facet) • Body fossil segment; Echinoderm (Invertebrate)
Geological Period
Likely Mississippian to Pennsylvanian (Carboniferous Period)
Estimated Age
Approximately 300 to 350 million years
Preservation Type
Recrystallization (calcite replacement) within a sedimentary matrix
Condition Assessment
Fair; the specimen is a fragmentary section embedded in matrix with significant weathering and breakage across the longitudinal plane
Taxonomic Classification
Phylum: Echinodermata; Class: Crinoidea; Order: various (tentative)
Morphological Description
A longitudinal section of a crinoid stem showing stacked circular ossicles. The specimen displays the characteristic 'stacked' appearance of columnals with visible sutures between individual plates and a central lumen area visible in the cross-break.
Rock Matrix
Gray fine-grained limestone or calcarenite containing secondary calcite veining
Formation & Location
Common in the Burlington Limestone (USA), Carboniferous Limestone Supergroup (UK), or similar Paleozoic marine deposits globally
Size & Dimensions
Approximately 2.5 cm long fragment; consistent with typical medium-sized Paleozoic crinoid stems
Value & Rarity
Estimated Market Value
$1 - $5 USD
Auction Estimate
$5 - $10 (typically sold in bulk study lots)
Rarity Assessment
Common; crinoid stem fragments are among the most abundant Paleozoic fossils found worldwide
Scientific Significance
Provides evidence of Paleozoic marine benthic environments and high-energy carbonate shelf ecosystems; demonstrates typical echinoderm skeletal architecture
Preparation Recommendations
Mechanical cleaning with a pin or air scribe to expose more of the stem from the matrix; store in a dry environment to prevent matrix degradation
Notable Features
The specimen provides a clear 'cross-sectional' view of the stem internal structure rather than the external surface, showing how the columnals fit together.