Who Was Feeding on My Coprolite?

Fossil Type: 
Composition: 
Location: 
Medway River, Sunbury , GA
United States
Georgia US
Period: 

This fascinating coprolite was expelled at a time when megalodons were the top sea predators (2.6 to 23 mya). It was discovered in the tidal Medway River near the ghost town of Sunbury, Georgia. While it is nearly impossible to determine coprolite producers, the overall shape, size, and lack of inclusions suggest this could have been donated to the fossil record by a crocodilian. If it was left by one of these reptiles, the animal would have measured approximately 545 cm (17.9 ft) long.

Although the size of this coprolite is impressive, the feeding traces on its surface are what make it remarkable. There are several sets of small striations that were likely left by small fish grazing on the surface (red arrows). The larger impressions appear to be the result of the bite action of a larger fish with multiple rows of teeth. It is unclear if the tooth impressions were left as the result of "tasting" behavior or if they were left incidentally while feeding on prey near the fecal matter.

A mold of the impressions revealed that those denoted by numbers 1-9 were left by conical teeth. The impressions on either side (A-E and a-e) appear to have been left by more flattened triangular teeth or bony plates.