Lepidodendron bark impression / Scale tree fossil
Lepidodendron cf. aculeatum • Plant body fossil, carbonaceous compression and impression
Geological Period
Carboniferous
Estimated Age
359 to 299 million years ago
Preservation Type
Carbonaceous compression/impression preserved in ironstone/mudstone matrix with minor mineral oxidation
Condition Assessment
Good, moderately complete surface preservation with clear diagnostic diamond patterns, though showing weathering and minor surface abrasion along the edges
Taxonomic Classification
Kingdom: Plantae, Division: Lycopodiophyta, Class: Lycopodiopsida, Order: Lepidodendrales, Family: Lepidodendraceae, Genus: Lepidodendron
Morphological Description
The specimen exhibits characteristic diamond-shaped or rhomboidal leaf cushions (leaf scars) arranged in helical patterns across the surface. Each cushion features a central scar (inframark) where the vascular bundle attached, flanked by lateral parichnos scars, showing distinct raised geometric ridges.
Rock Matrix
Sideritic ironstone nodule (clay-ironstone) containing fine-grained argillaceous mudstone
Formation & Location
Mazon Creek formation (Illinois, USA) or similar Carboniferous coal-measure formations globally
Size & Dimensions
Approximately 5 to 7 cm in length, consistent with typical fragments of medium-sized branch or trunk bark from lycopsid trees
Value & Rarity
Estimated Market Value
20 to 50 USD
Auction Estimate
30 to 75 USD
Rarity Assessment
Common, widely found in Carboniferous coal-bearing strata worldwide
Scientific Significance
Provides crucial evidence of the massive coal-forming swamp forests of the Paleozoic era, illustrating the morphology and evolutionary adaptations of extinct arborescent lycophytes
Preparation Recommendations
Mechanical cleaning with a fine pin-vise or air-abrasive using gentle parameters; store in stable, dry conditions to prevent matrix degradation
Notable Features
Well-defined geometric leaf cushion arrangement displaying sharp diagonal offset rows and clearly visible vascular leaf scar impressions