Fenestrate Bryozoan in Limestone Matrix
Fenestella sp. cf. F. elegantula • Body fossil, invertebrate colonial organism (Bryozoa)
Geological Period
Carboniferous to Permian (likely Paleozoic)
Estimated Age
290 to 350 million years
Preservation Type
Calcitic replacement and external/internal mold preservation within a carbonate matrix
Condition Assessment
Good. The specimen shows clear structural detail of the delicate lace network, though it represents a partial, broken fragment within a heavily weathered matrix.
Taxonomic Classification
Phylum Bryozoa, Class Stenolaemata, Order Fenestrata, Family Fenestellidae
Morphological Description
The specimen exhibits a delicate, lace-like or fan-shaped colonial structure with branching stems (branches) connected by cross-bars ( dissepiments ), creating a regular grid of rectangular or oval openings (fenestrules). The autozooid apertures are visible along the surface as tiny aligned pores.
Rock Matrix
Light tan to yellowish fossiliferous limestone with secondary calcite mineralization
Formation & Location
Mississippian and Pennsylvanian limestone formations across North America and Western Europe
Size & Dimensions
Approximately 4 cm by 3.5 cm, consistent with a modest fragment of a larger colony typical of the taxon
Value & Rarity
Estimated Market Value
$10 - $30 USD
Auction Estimate
$15 - $25 USD
Rarity Assessment
Common. Fenestrate bryozoan fragments are frequently encountered in Paleozoic marine deposits globally.
Scientific Significance
Important for reconstructing Paleozoic shallow marine shelf environments, as fenestrate bryozoans were prolific filter feeders and major contributors to carbonate buildup and ancient reef ecosystems.
Preparation Recommendations
Gentle mechanical cleaning with a soft brush and water or pin-vise to remove excess matrix without damaging the fragile lace structure. Store in a stable, dry environment.
Notable Features
The exceptionally well-preserved delicate lacy meshwork contrasted sharply against the coarse limestone background, showcasing the classic 'lace coral' architecture of Paleozoic bryozoans.