The world’s only known Tyrannosaurus rex coprolite

Royal Saskatchewan Museum, Regina, Canada

EMu user since 2004

Coprolite 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 Tyrannosaurus rex 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.

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

Locality: Frenchman River Valley, Saskatchewan