Carboniferous Tree Bark Impression / Stigmaria Root Cast
Lepidodendron cf. squamatum or Stigmaria ficoides structures • Trace fossil and impression/cast of plant material, specifically Lepidodendron or Sigillaria rootlets/bark features within a terrestrial or marginal-marine clastic deposit
Geological Period
Carboniferous (Pennsylvanian sub-period)
Estimated Age
300 to 320 million years
Preservation Type
Iron-oxide replacement and carbonization within an external mold/impression
Condition Assessment
Fair to Good. Weathered from a creek bed, showing natural surface abrasion, iron staining, and incomplete anatomical margins typical of fluvial transport and sub-aerial exposure
Taxonomic Classification
Kingdom: Plantae, Division: Lycopodiophyta, Class: Lycopodiopsida, Order: Lepidodendrales, Family: Lepidodendraceae
Morphological Description
The specimen displays irregular, flattened, iron-stained brown organic impressions and possible node-like or rootlet attachment scars (stigmarian rootlets) embedded on the bedding plane of a grey sandstone slab. The texture shows varied relief with reddish-brown oxidized iron staining (limonite/hematite) contrasting against the lighter grey matrix.
Rock Matrix
Fine-grained micaceous sandstone or siltstone with iron oxide (limonite) staining along the fossil interfaces
Formation & Location
Western Kentucky coal fields, tradable formations like the Carbondale Formation or Tradewater Formation, derived from regional creek beds
Size & Dimensions
Approximately 30 cm by 25 cm, consistent with medium-sized fragments of Carboniferous swamp flora axes and root structures
Value & Rarity
Estimated Market Value
$20 to $50
Auction Estimate
$15 to $40
Rarity Assessment
Common throughout the coal-bearing strata of Kentucky and the broader Illinois Basin
Scientific Significance
Provides evidence of the extensive lycopod swamp forests that covered North America during the Pennsylvanian period, which formed the vast coal deposits of the region and significantly altered the global atmosphere
Preparation Recommendations
Gentle mechanical cleaning with a soft brush and water to remove remaining clay or silt; stabilization with a diluted polyvinyl acetate (PVA) or similar consolidant if the matrix is friable. Store in a dry environment.
Notable Features
Distinctive reddish-brown iron oxide preservation pattern creating high visual contrast against the grey sandstone slab, alongside possible appendicular rootlet scars
Notes
Owensboro, Kentucky. Creek bed