Coprolite (Fossilized Dung)
Indeterminate vertebrate; possibly reptilian (crocodilian or dinosaurian) based on texture and mineralization • Trace fossil (Ichnofossil); fecal matter
Geological Period
Likely Cretaceous or Jurassic, though coprolites occur throughout the Phanerozoic
Estimated Age
Approx. 66 to 200 million years
Preservation Type
Permineralization or Replacement; typically replaced by calcium phosphate (apatite), siderite, or limonite
Condition Assessment
Fair to Good; the specimen is largely intact but shows significant weathering and lacks the distinct 'spiral' or 'pinched' ends seen in premium grade coprolites
Taxonomic Classification
Kingdom: Animalia; Ichnogenus: Likely cf. Coprulus or similar depending on the specific producer
Morphological Description
Irregular, bulbous, and cylindrical mass with a rough, textured surface. Displays characteristic inclusions, faint segments, and a reddish-brown iron-rich coloration typical of mineralized animal waste.
Rock Matrix
Iron-rich sedimentary matrix, likely ferruginous sandstone or mudstone; evidence of hematite or limonite staining
Formation & Location
Commonly found in the Hell Creek Formation (USA), Morrison Formation (USA), or similar Mesozoic sedimentary deposits worldwide
Size & Dimensions
Approximately 5-8 cm in length; fits within the mid-range for terrestrial vertebrate trace fossils
Value & Rarity
Estimated Market Value
$15.00 - $35.00 USD
Auction Estimate
$20.00 - $50.00 USD
Rarity Assessment
Common; coprolites are widely distributed in various sedimentary horizons, though high-quality specimens with inclusions are more sought after
Scientific Significance
Crucial for dietary analysis (paleodiet) and understanding ancient food webs; may contain inclusions of bone fragments, scales, or plant matter from the producer's last meal
Preparation Recommendations
Keep dry; clean with a soft brush only. Avoid water or aggressive solvents as the iron-bearing minerals may oxidize or crumble. Display in an acrylic case with stable humidity.
Notable Features
Distinctive reddish-brown oxidation and a 'chunky' texture that suggests a high mineral or bone content in the original fecal matter; lacks the distinct smooth surface of shark coprolites.