Coprolite (Fossilized Dung)
Indeterminate vertebrate producer (possibly crocodilian or reptilian origin based on morphology and color) • Trace fossil (Ichnofossil); non-skeletal organic remains
Geological Period
Likely Cretaceous or Jurassic
Estimated Age
Approx. 66 to 150 million years
Preservation Type
Permineralization and replacement; heavy concentration of hematite or limonite giving it the distinctive reddish coloration.
Condition Assessment
Good; the specimen is largely intact with clear diagnostic structure, though surface weathering has softened some of the finer detail.
Taxonomic Classification
Kingdom: Animalia; Ichnotaxon: Coprolitidae (classification based on producer is usually indeterminate without inclusions)
Morphological Description
Irregular, bulbous, and segmented shape with a reddish-brown, iron-rich patina. Features a coarse, grainy surface texture with visible folding and some inclusions that may represent undigested bone fragments or plant matter. The structure shows signs of intestinal pressure during deposition (pinched ends).
Rock Matrix
The specimen appears mostly freed from matrix, but residues suggest a siltstone or iron-rich mudstone origin.
Formation & Location
Commonly found in the Hell Creek Formation (USA), Kem Kem Beds (Morocco), or similar Mesozoic terrestrial/estuarine deposits.
Size & Dimensions
Approximately 5-8 cm in length, which is a standard size for medium-sized Mesozoic tetrapod terrestrial producers.
Value & Rarity
Estimated Market Value
$25.00 - $60.00 USD
Auction Estimate
$30.00 - $75.00 USD
Rarity Assessment
Common; while fossils of this type are abundant in certain formations, well-structured examples with distinct inclusions are sought after by collectors.
Scientific Significance
Provides critical data on the diet and digestive physiology of extinct organisms, and helps reconstruct trophic levels within ancient ecosystems.
Preparation Recommendations
Mechanical cleaning with soft brushes to remove surface dust. No chemical prep is recommended due to potential oxidation of iron-rich minerals. Keep in a low-humidity environment.
Notable Features
Distinctive reddish-ochre mineralization and 'pinched' morphological structure characteristic of reptilian digestive tracts.