Fossiliferous Limestone Clast (Shell Fragment)
Incertae sedis (unidentifiable fragment) • Body fossil fragment (Invertebrate macrofossil)
Geological Period
Uncertain; potentially Paleozoic to Mesozoic era
Estimated Age
Approx. 66 to 450 million years
Preservation Type
Recrystallization/Mineral replacement (likely calcite over carbonate shell material)
Condition Assessment
Poor; highly fragmented, weathered, and lacking diagnostic anatomical boundaries
Taxonomic Classification
Phylum: Mollusca or Brachiopoda; Class: Bivalvia or Articulata
Morphological Description
Small, angular fragment showing a white, calcitic surface with faint, parallel growth lines or ribbing structures. It lacks a complete diagnostic shape.
Rock Matrix
Light gray limestone or fine-grained calcareous mudstone
Formation & Location
Common in sedimentary basins worldwide, such as the Midwestern USA Crinoidal limestones or UK Jurassic Coast formations
Size & Dimensions
Approximately 2cm x 1.5cm; very small relative to typical complete specimens
Value & Rarity
Estimated Market Value
$0.00 - $1.00 USD
Auction Estimate
Negligible/No commercial auction value
Rarity Assessment
Common; extremely ubiquitous in sedimentary rock debris and gravel
Scientific Significance
Low; indicates presence of marine life in a carbonate environment but provides insufficient data for stratigraphic or evolutionary study
Preparation Recommendations
No preparation required; wash with water to remove surface dust. Store in a dry box.
Notable Features
The specimen is a typical example of field debris where ancient sea floor materials have been crushed into inorganic-looking rock chips.