Rugose Coral (Horn Coral)
Rugosa cf. solitary coral • Body fossil, marine invertebrate
Geological Period
Devonian (or potentially Ordovician to Permian)
Estimated Age
359 to 419 million years
Preservation Type
Silicification and calcitic permineralization/replacement
Condition Assessment
Good condition; fragment of a solitary coral showing clear external and internal septal structures with minor weathering on the edges
Taxonomic Classification
Phylum Cnidaria, Class Anthozoa, Subclass Rugosa
Morphological Description
Exhibits a distinct conical or horn-shaped corallite structure with visible vertical septa radiating inward and prominent transverse growth lines along the exterior wall.
Rock Matrix
Crystalline limestone / fossiliferous dolostone matrix
Formation & Location
Widely distributed globally; common in North American formations such as the Onondaga Limestone or Jeffersonville Limestone
Size & Dimensions
Approximately 8 cm in length and 3 cm in maximum width, consistent with medium-sized solitary rugose corals
Value & Rarity
Estimated Market Value
$15 - $40 USD
Auction Estimate
$20 - $50 USD
Rarity Assessment
Common
Scientific Significance
Important for paleoenvironmental reconstructions, indicating shallow, warm, tropical marine environments during the Paleozoic era
Preparation Recommendations
Gentle mechanical cleaning with a soft brush to remove loose matrix; no aggressive acid preparation recommended to preserve fine surface details; store in a stable, dry environment
Notable Features
Well-defined longitudinal septal grooves and internal partitioning visible along the broken face, providing a clear cross-sectional view of the coral's internal architecture