Calamites Stem Impression
Calamites cf. suckowii • Body fossil / Plant impression (Adpression)
Geological Period
Carboniferous (Late Pennsylvanian)
Estimated Age
299 - 318 million years
Preservation Type
Compression and impression with likely iron-oxide (hematite/limonite) replacement, giving it a distinctive reddish-brown color.
Condition Assessment
Fair to Good. While the ribbing is distinct and clear, the specimen is a fragmentary piece without node intersections or leaf whorls.
Taxonomic Classification
Kingdom: Plantae, Phylum: Pteridophyta, Class: Equisetopsida, Order: Equisetales, Family: Calamitaceae, Genus: Calamites
Morphological Description
The specimen displays parallel longitudinal ribs and grooves typical of the internal cast or external impression of a horsetail-like tree stem. Fine vertical striations are visible within the larger ribs. Transverse nodes (the horizontal joints where branches/leaves would emerge) are absent in this specific fragment, suggesting it is an internodal section.
Rock Matrix
Ferruginous sandstone/siltstone, often referred to as 'red bed' matrix, indicating an oxidizing terrestrial environment.
Formation & Location
Likely sourced from the Carboniferous formations of the Appalachian Basin (USA), such as the Pottsville Formation, or European Coal Measures (UK/Germany).
Size & Dimensions
Approximately 8-10 cm in length and 5-6 cm in width. Small to medium-sized for a Calamites fragment, as these trees could reach 30 meters in height.
Value & Rarity
Estimated Market Value
$15 - $35 USD
Auction Estimate
$20 - $50 USD
Rarity Assessment
Common. Calamites fragments are among the most frequently found plant fossils in Carboniferous coal-bearing strata worldwide.
Scientific Significance
Calamites are key indicator fossils for the 'Coal Forests' of the Carboniferous. They provide significant data on paleo-wetland ecosystems and the evolution of vascular tissue and tree-like growth habits in early land plants.
Preparation Recommendations
Requires minimal preparation. Keep dry to prevent oxidation of the iron-rich matrix. Should be stored in a padded tray to prevent chipping of the brittle sandstone edges.
Notable Features
The most notable feature is the vivid red coloration of the matrix, which suggests it was found in an iron-rich sedimentary layer, differing from the more common grey shale or black coal matrix fossils.