Detailed view of the two coprolites in the mouth of the simplex gar. Two of the gar teeth are imbedded in the larger coprolite seen on the right side of the photo.
Photos courtesy of G. Frandsen.

SOLOMONS, MD – Coprolites are fossilized feces. Two coprolite-enthusiasts – George Frandsen from Jacksonville, Florida working in collaboration with Calvert Marine Museum (CMM) Curator of Paleontology, Dr. Stephen J. Godfrey – have just published a new coprolite first. The description of a 52-million-year-old fossil garfish from the famous Green River Formation near Kemmerer, Wyoming was found with fossilized feces in its mouth (Figures 1-3). This is the first fossil ever found in which feces is preserved in the mouth of an animal. The fossil record is an endless source of fascination.

Nearly complete and articulated skeleton of Atractosteus simplex (the simplex gar) in a right lateral view. The red circle towards the top of the image outlines the area where the coprolites between the jaws of the gar are preserved.

Dean Sherman discovered the fossil gar in 2017 in his private fossil quarry near Kemmerer. Sherman recovered the 36 inch-long specimen in several pieces, which he reassembled and removed the thin veneer of rock covering the fish. While preparing the head, he noticed the two coprolites between its jaws (Figs. 2-3). Senior author George Frandsen subsequently purchased the fossil for his growing collection of coprolites.

View of the right mid-jaw section of the gar. The red circle outlines the coprolite in which two teeth are imbedded (see also Figure 3 for more detail).

We do not know if the three-foot-long gar was deliberately trying to eat the feces at the time it died. Maybe that’s why it died! It is possible that the gar was biting the feces to assess their palatability and then died. Another possibility is that the feces entered the gar’s mouth serendipitously at or near the time of its death. Although much less likely because the coprolites are so well formed, it is also possible that what we are referring to as fossilized feces is actually fossilized vomit (i.e., regurgitalites) that made its way into the fish’s mouth just before, during the throws of death, or immediately after it died. At last, there is a fossil that gives meaning to the phrase “Eat —- and die.”

 

Read more in The Ecphora, the CMM Fossil Club’s newsletter, at bit.ly/Ecphora-Vol34-No1.