Coprolite (Fossilized Dung)
Ichnogenus cf. Dicynodontocopros (if from Triassic beds) or indeterminate vertebrate coprolite • Trace fossil (Ichnofossil); non-skeletal organic remains
Geological Period
Triassic to Jurassic (likely Mesozoic)
Estimated Age
Approx. 150 - 230 million years
Preservation Type
Permineralization and replacement; mineralized by phosphate (apatite), iron oxides, and silicates.
Condition Assessment
Fair to Good; the specimen is weathered and lacks high-definition surface detail, though the mass is largely intact and demonstrates clear biological morphology.
Taxonomic Classification
Kingdom: Animalia; Ichnotaxon: likely Dicynodontia or Archosauria (specific classification is difficult without chemical analysis)
Morphological Description
Irregular, lumpy, and bulbous morphology with possible segmented or 'pinched' appearance. The surface lacks the distinct spiral grooves of shark coprolites, suggesting a terrestrial vertebrate origin. Internal textures appear partially brecciated with inclusions that may represent undigested bone fragments or plant matter (bioclastic inclusions).
Rock Matrix
Hematitic or ferruginous mudstone/siltstone; the red coloration suggests a highly oxidized terrestrial depositional environment with high iron content.
Formation & Location
Likely the Chinle Formation (Southwestern USA) or similar red-bed sequences such as the Ischigualasto Formation (Argentina).
Size & Dimensions
Approximately 5-8 cm in length; typical for a medium-sized terrestrial herbivore or omnivore.
Value & Rarity
Estimated Market Value
$20 - $45 USD
Auction Estimate
$30 - $60 USD
Rarity Assessment
Common; coprolites are abundant in specific Mesozoic 'red bed' formations, although well-defined large specimens are more desirable.
Scientific Significance
Provides critical data on ancient diets (trophic interactions), digestive physiology, and the presence of organisms in environments where body fossils might not preserve well.
Preparation Recommendations
Keep dry; stabilize with a thin coat of Paraloid B-72 if crumbling occurs. Cross-sectioning and polishing one end could reveal fascinating internal inclusions/dietary evidence.
Notable Features
Heavy mineralization with iron oxides gives it a distinctive 'rusty' appearance; some visible internal cavities may have originally contained organic gas pockets or undigested fibers.