Ed Dobrzanski holding the theropod coprolite

If we think about it at all, most of us tend to consider dung (poop) as a substance to be gotten rid of, not something to be collected and treasured. And that is the case for at least 99.9% of it, but of course the situation is different when the dung is in fossilized form, and when it comes from giant, long-extinct creatures.

Fossilized dinosaur dung, or coprolites, has been studied for nearly two centuries. Dinosaur coprolites can tell us quite a bit about the diet and physiology of the creatures, and of course they also make interesting “conversation pieces.”

The splendid agatized theropod coprolite (V-3106)

The Museum is fortunate to have a few good coprolites in our collection, but the quality of this collection was greatly enhanced by a recent donation from long-time Community Associate Ed Dobrzanski. Ed gave us, from his personal collection, two superb coprolites that he had purchased from a dealer about 25 years ago. These are both from the Upper Jurassic Morrison Formation of Utah, the 150 million year-old home of famous dinosaur bones such as those of Allosaurus, Stegosaurus, Diplodocus, and Apatosaurus/Brontosaurus.

The first coprolite is the dung of a meat-eating theropod, possibly Allosaurus, since it is the most common large theropod found in the Morrison Formation. This example, perhaps rather graphically, carries the shape associated with its original source!

The second specimen is from large plant-eating dinosaur, possibly a sauropod such as Apatosaurus. At first glance, it appears to be a very ordinary, concretion-like rock. However, it has been cut and polished, and the internal structure is revealed as a strikingly beautiful series of agatized blobs and whorls.

The sauropod coprolite, with external surface above and cut and polished surface below (V-3105)