Fossilized Trilobite or Arthropod Exoskeleton / Segmented Organism
Indeterminate arthropod / cf. Trilobita • Body fossil / impression preserved in sedimentary rock, invertebrate classification
Geological Period
Cambrian to Devonian (Likely Paleozoic era)
Estimated Age
350 to 500 million years
Preservation Type
Carbonaceous compression and natural mold/impression with minor mineral replacement
Condition Assessment
Fair to Good. Partial specimen showing significant central crushing, breakage along the matrix, but retaining clear, well-defined segmented impressions
Taxonomic Classification
Phylum Arthropoda, Subphylum Trilobita or Crustacea
Morphological Description
Elongated, bilaterally symmetrical fossil featuring distinct transverse segmentation (ribs or pleural segments) arching outwards from a central axis or rachis. The texture shows parallel ridges along the segmented body segments with fine lineation details visible on the weathered surface.
Rock Matrix
Brownish-grey weathering shale or fine-grained siltstone with iron oxide staining
Formation & Location
Paleozoic marine shales globally, commonly found in regions such as the Burgess Shale (Canada), Anti-Atlas (Morocco), or various formations across North America and Europe
Size & Dimensions
Approximately 12 cm to 15 cm in length, typical for large-scale trilobite or arthropod fragments
Value & Rarity
Estimated Market Value
$50 - $150 USD
Auction Estimate
$75 - $200 USD
Rarity Assessment
Common to Uncommon, depending on the exact geological formation and specific taxa
Scientific Significance
Provides valuable insight into Paleozoic marine benthic ecosystems, soft-tissue or flattened compression preservation, and arthropod morphology during rapid evolutionary periods
Preparation Recommendations
Mechanical preparation using delicate pneumatic air scribes under magnification to expose obscured segments, followed by stabilization with a dilute acrylic or polyvinyl acetate consolidant if the shale matrix is prone to crumbling
Notable Features
Clearly articulated transverse pleural ribs radiating from a central axis, showing exceptional parallel alignment and distinct surface weathering patterns