Encrusting Bryozoan or Fossilized Coprolite Fragment
Indeterminate encrusting bryozoan or cf. Coprolus sp. • Body/Trace Fossil, Invertebrate or Ichnofossil
Geological Period
Likely Ordovician to Devonian or Cretaceous/Paleogene depending on exact locality
Estimated Age
Estimated 66 to 450 Million Years
Preservation Type
Mineral replacement and permineralization with secondary silification and water-worn tumbling.
Condition Assessment
Fair; the specimen is heavily weathered and water-worn, obscuring fine diagnostic anatomical details.
Taxonomic Classification
Phylum: Bryozoa or Kingdom: Animalia (Ichnotaxon)
Morphological Description
A rounded, ovate specimen featuring a dense, pitted, rugose surface texture on one side and a smoother, water-worn texture on the other. The pitted surface resembles zooecia (chambers) or digestive compression marks.
Rock Matrix
Chert or fine-grained siliceous siderite matrix with iron-oxide staining.
Formation & Location
Commonly found in secondary gravel deposits or fluvial environments such as the Mississippi River basin or North Sea beaches.
Size & Dimensions
Approximately 2-3 cm in length; typical for isolated fragments or micro-faunal colonies.
Value & Rarity
Estimated Market Value
$5.00 - $15.00 USD
Auction Estimate
$10.00 - $25.00 USD in a bulk lot
Rarity Assessment
Common; these fragments are frequently found in gravel deposits and along riverbeds.
Scientific Significance
Provides data on ancient marine encrusting communities or paleo-dietary habits and sediment transport in fluvial or coastal systems.
Preparation Recommendations
No invasive preparation needed; clean with a soft brush and distilled water. Store in a padded display case to prevent further abrasion.
Notable Features
Distinct contrast between the highly textured, crystalline rugosity and the smooth, patinated exterior of the stone.