This trace fossil is a dinosaur coprolite from San Juan County in northwestern New Mexico. Coprolites are fossilized feces and are important for understanding dinosaurs as living animals (paleobiology). Most coprolites were produced by carnivorous animals, in part because digested bone (composed of the mineral phosphate) can aid in fossilization. This fossil preserves an interesting shape, but does not contain any obvious bones or teeth. Often, coprolites include fish scales, tooth fragments, and shards of bone.

Paleontologists divide fossils into two types: body fossils (actual bones, teeth, shell, and other animal parts) and trace fossils (tracks, skin impressions, and coprolites). Sometimes called "fossilized behavior," trace fossils can provide information about how the organism acted in life.