Fossilized Colonial Coral and Brachiopod Assemblage
Indeterminate colonial coral cf. Rugose coral assemblage • Body fossil, invertebrate colonial scleractinian or rugose coral with associated shelly fragments in a limestone or calcareous matrix
Geological Period
Devonian to Carboniferous (Paleozoic Era)
Estimated Age
350 to 400 million years old
Preservation Type
Permineralization and calcitic replacement within a sedimentary limestone matrix
Condition Assessment
Fair to Good. Shows weathering and surface erosion common to weathered limestone exposures, but internal coral calices and structures remain distinctly visible and three-dimensional in relief.
Taxonomic Classification
Phylum: Cnidaria, Class: Anthozoa, Order: Rugosa or Tabulata, Family: Various, Genus: Undetermined colonial coral
Morphological Description
The specimen exhibits well-defined internal septa and corallite walls creating a honeycomb or ribbed radial structure, characteristic of colonial rugose or tabulate corals. Interspersed with fragmented shell material, likely brachiopods or bivalves, showing detailed internal growth ridges and ribbed surface textures.
Rock Matrix
Weathered, highly fossiliferous limestone or calcareous mudstone with iron oxide staining (buff/brown coloration)
Formation & Location
Commonly found in Paleozoic marine limestone formations throughout North America and Europe, such as the Onondaga Formation or Devonian strata of the Midwest United States
Size & Dimensions
Medium-sized hand specimen, approximately 10 to 15 cm across, representing a fragment of a larger colonial fossil reef structure
Value & Rarity
Estimated Market Value
20 to 50 USD
Auction Estimate
15 to 40 USD
Rarity Assessment
Common. Colonial corals and fossiliferous limestone blocks of this type are widely distributed globally in appropriate Paleozoic rock strata
Scientific Significance
Provides valuable insight into ancient Paleozoic shallow marine reef ecosystems, paleoecology, and the biodiversity of tropical shallow seas during the Devonian/Carboniferous periods
Preparation Recommendations
Gentle mechanical cleaning with a soft brush and water to remove loose debris; optional stabilization with a dilute PVA or acrylic consolidant if dusting occurs; store in a dry environment
Notable Features
The exposed radial septa of the coral corallites show exceptional relief and hollowed-out weathering patterns, revealing the internal skeletal framework quite clearly alongside embedded shelly hash