Mineralized Coprolite (Fossilized Dung)
Indeterminate reptile or mammal producer (cf. Crocodylian or Turtle) • Trace fossil (Ichnofossil) - Coprolite
Geological Period
Cretaceous or Eocene (likely)
Estimated Age
Approximately 50 to 100 million years
Preservation Type
Permineralization and replacement with iron-rich minerals (Siderite or Goethite) or phosphates
Condition Assessment
Good; specimen is stable and largely complete but shows significant environmental tumbling and erosion of surface detail.
Taxonomic Classification
Kingdom: Animalia; Ichnogenus: Coprolithes (unspecified producer)
Morphological Description
Elongated, sub-cylindrical to irregularly bolus-shaped specimen with an uneven, pitted surface. Features visible inclusions and possible shrinkage cracks typical of desiccation prior to fossilization. One end shows a more tapered pinch-point consistent with rectal expulsion.
Rock Matrix
Minimal remaining matrix; appears to be a free-standing specimen likely weathered out of a siltstone or claystone layer.
Formation & Location
Commonly found in the Hell Creek Formation (USA), Peace River (Florida), or the Isle of Wight (UK) depending on specific locality.
Size & Dimensions
Approximately 4 to 6 cm in length; consistent with mid-sized vertebrate excrement.
Value & Rarity
Estimated Market Value
$15 - $35 USD
Auction Estimate
$20 - $50 USD
Rarity Assessment
Common; coprolites are widely distributed in various sedimentary basins worldwide.
Scientific Significance
Provides data on ancient diets, digestive systems, and the presence of specific fauna in a paleoenvironment where skeletal remains may be scarce.
Preparation Recommendations
None required beyond gentle cleaning with a soft brush and distilled water. Maintain in a dry, low-humidity environment to prevent pyrite disease if iron content is high.
Notable Features
Features a dark, ferruginous coating suggesting an oxygen-poor depositional environment; contains visible surface depressions that may represent air bubbles or consumed organic matter.