Overview

A coprolite is a piece of fossilized feces produced by an animal. Unlike bones or shells, coprolites are trace fossils that record behavior — principally diet and feeding interactions — rather than the anatomy of the producer. The term derives from Greek roots and was applied early in the history of palaeontology.

Formation and identification

Coprolites form when fecal material is rapidly buried and mineralized, usually by the replacement or infilling of the original organic matter with minerals such as calcium phosphate or silica. Over geological time this process hardens the material and preserves internal structure. Identification relies on texture, composition and context: common features include embedded fragments of bone, shell, plant tissue or scales, spiral or elongated shapes that reflect gut anatomy, and location near likely producers or feeding sites.

Scientific importance

Because they often contain undigested or partially digested remains, coprolites provide direct evidence of diet, trophic relationships and digestive processes. They can preserve microscopic items such as pollen, plant fibers and parasite eggs, which help reconstruct ancient environments, seasonality and host–parasite interactions. Modern techniques used to study coprolites include thin-section microscopy, chemical analyses of preserved biomolecules, and non‑destructive imaging such as X‑ray computed tomography.

History and terminology

The name combines the Greek words for dung and stone; the coinage and first formal description are attributed to William Buckland in 1829. Paleontologists distinguish coprolites from other preserved excreta of more recent origin, often called paleofaeces, which may retain more organic detail but are not fully mineralized. Coprolites are classed as trace fossils because they document behavior rather than body parts; see trace fossil for broader context. The etymology is explained at Greek roots and early descriptions at Buckland’s works.

Examples, uses and notable facts

  • Dinosaur coprolites can contain crushed bone fragments, indicating carnivory or scavenging.
  • Fish and shark coprolites may preserve scales or teeth and sometimes show spiral internal casts tied to gut anatomy.
  • Coprolites have been mined historically as a phosphate source for fertilizer in some regions, an industrial use distinct from their scientific value.

Studying coprolites complements other fossil evidence and can reveal aspects of ancient ecosystems that body fossils alone cannot, making them valuable windows into past life and behavior.