Coprolites and Mammalian Carnivores from Pipestone Springs, Montana, and their Paleoecological Significance

ABSTRACT Pipestone Springs Main Pocket (PSMP) (Renova Formation, Jefferson County, Montana) has yielded an unusually rich concentration of mostly small-bodied Chadronian (late Eocene) mammals. Coprolites are common at PSMP and indicate which taxa and skeletal elements were consumed, as well as provide insight as to which carnivore species were likely to have deposited their feces at the site. Two distinct coprolite groupings were recognized based on differences in diameter, morphology, and abundance of bone. The sample of larger coprolites ranges in diameter from 16–29 mm and lacks a distinct mode. Some of the larger coprolites contain bone, but if present, it is sparse, poorly preserved, and unidentifiable. The sample of smaller coprolites varies in diameter from 4–15 mm and has a prominent mode at 10–11 mm. Many of the smaller coprolites contain abundant bone that is often highly fragmented. Osteoderms, bone ends, or dental elements identified to taxon in smaller coprolites indicate that marsupials, liz...