Pennsylvanian Plant Impressions
cf. Pecopteris or Neuropteris species fragments • Plant compression/impression body fossil
Geological Period
Carboniferous (Pennsylvanian sub-period)
Estimated Age
299 to 318 million years
Preservation Type
Carbonaceous compression and impression with iron oxide staining (limonitic/hematitic)
Condition Assessment
Fair; the plant material is fragmented and lacks high-contrast detail, though the matrix is stable.
Taxonomic Classification
Kingdom: Plantae; Phylum: Pteridophyta; Class: Pteridopsida; Order: Marattiales; Family: Pecopteridaceae
Morphological Description
Small, fragmented foliage impressions showing partial pinnules or leaflets. The structures exhibit faint venation patterns and an elongated, lanceolate shape characteristic of seed ferns or true ferns.
Rock Matrix
Reddish-brown ferruginous siltstone or sideritic mudstone with high iron oxide content
Formation & Location
Possible Mazon Creek (Illinois) or Pottsville Formation (Pennsylvania/West Virginia), USA
Size & Dimensions
Specimen block approx. 50-70mm in length; individual plant fragments range from 5mm to 15mm
Value & Rarity
Estimated Market Value
$5.00 - $15.00 USD
Auction Estimate
$10.00 - $20.00 USD (typically sold in bulk lots or as educational specimens)
Rarity Assessment
Common; fragmentary plant remains in Carboniferous ironstone and shales are globally abundant.
Scientific Significance
Provides evidence of Carboniferous 'Coal Forest' swamp ecosystems and local paleoflora distribution through rapid burial in anaerobic conditions.
Preparation Recommendations
Keep dry to prevent oxidation of iron minerals; light brushing for cleaning; no chemical stabilizers required unless the matrix is crumbly.
Notable Features
The distinctive reddish-orange 'rust' color of the matrix suggests a high concentration of oxidized iron, common in terrestrial or deltaic depositional environments.