The world’s only known Tyrannosaurus rex coprolite

Object: The world’s only known Tyrannosaurus rex coprolite (RSM P2609.1)

Locality: Frenchman River Valley, Saskatchewan

Royal Saskatchewan Museum, Regina, Canada

EMu user since 2004


augustCoprolite is the scientific term for fossilised dung. Coprolites are relatively common and can provide scientists with a wealth of information about diet and digestive processes. Unfortunately, determining who made the dropping is usually a problem.

In 1995 Wendy Sloboda of the RSM discovered the largest known fossilized dung in 65 million-year-old sediments in the Frenchman River Valley in southwestern Saskatchewan. It measures 44x16x13 cm and weighs over 7kg.

This coprolite was a rare discovery because it can be definitely attributed to a carnivorous dinosaur. The coprolite contains shattered bone fragments from a juvenile dinosaur, indicating that a large carnivore must have deposited the dung. The only carnivore known from that time and area that was large enough to produce a coprolite of this size is Tyrannosaurus rex.

The shattered bone fragments suggest that Tyrannosaurusrex did not chew its food, but rather shattered and swallowed a lot of bones while feeding on its prey. The fact that the bone was not completely digested by the stomach acids is also a previously unknown insight into the biology of an animal that lived 65 million years ago.