Crinoid and Brachiopod Fossiliferous Limestone Matrix
Mixed marine invertebrate fragments (undetermined crinoid columnals and articulates, various strophomenid or spiriferid brachiopods) • Body fossil assemblage, invertebrate marine fossiliferous rock
Geological Period
Devonian to Mississippian
Estimated Age
350 to 400 million years old
Preservation Type
Original calcitic shell material partially dissolved, leaving behind molds, casts, and recrystallized fossil fragments within a sedimentary matrix
Condition Assessment
Good, typical for a random block sample; heavily weathered with surface erosion and broken fossil fragments, but structurally stable
Taxonomic Classification
Phylum Brachiopoda; Phylum Echinodermata, Class Crinoidea
Morphological Description
The specimen displays numerous broken and fragmented organic remains, including ribbed brachiopod valve impressions and circular crinoid stem columnal segments randomly distributed throughout the matrix. Internal and external molds are visible as hollow cavities and surface impressions showing radial symmetry and fine striations.
Rock Matrix
Fossiliferous limestone and calcareous grainstone matrix with light tan to buff coloration
Formation & Location
Commonly found in Paleozoic marine formations globally, such as the Jefferson Formation in North America or the Carboniferous Limestone of the British Isles
Size & Dimensions
Approximately 12 cm by 10 cm by 6 cm, typical for a hand-sample sized fossiliferous block
Value & Rarity
Estimated Market Value
$15 - $30
Auction Estimate
$10 - $25
Rarity Assessment
Common
Scientific Significance
Illustrates shallow, high-energy ancient marine shelf environments, rich in carbonate-secreting invertebrates, providing insights into Paleozoic benthic community structures
Preparation Recommendations
No intensive preparation required; can be lightly brushed with a soft nylon brush to remove surface dust. Store in a dry, stable indoor environment
Notable Features
High density of mixed crinoid stem ossicles and fragmentary brachiopod shells demonstrating a high-energy tempestite or coquina layer accumulation