Coprolite

Physical Properties

Hardness: 3.5-5.5 (Mohs scale), Color: Brown, gray, or tan depending on mineral replacement, Luster: Dull to sub-vitreous, Structure: Cylindrical or amorphous trace fossil; may contain inclusions like bone bits.

Formation & Geological History

Fossilized animal feces formed through mineralization (permineralization), primarily during the Mesozoic Era (250-66 million years ago) in sedimentary basins.

Uses & Applications

Scientific research (paleontology), educational displays, fossil collecting, and occasionally used as a conversation piece in jewelry.

Geological Facts

Coprolites provide invaluable information about the diet and physiology of extinct organisms. The largest coprolite ever found is over 60 cm long and is attributed to a T-Rex.

Field Identification & Locations

Identify by its 'fecal' shape (often cylindrical or twisted), presence of spiral patterns or inclusions, and its weight due to mineral replacement; commonly found in fossil-rich formations like the Hell Creek Formation.

Identified on: 5/1/2026

Mode: Standard