Coprolite with Feeding Traces

Fossil Type: 
Composition: 
Location: 
Texas City Dike Texas City, Galveston County
United States
US
Dimensions: 
32 mm dia. x 64 mm long

This coprolite weathered out of dredge spoil piles deposited along the Texas City Dike in the 1970's and 1980's. The material was dredged from a nearby shipping channel. Because teeth from Ice Age (aka Pleistocene) animals including horses, camels and bison were similarly found, the coprolites are likely the same age. Why are terrestrial (land-dwelling) animal remains being dredged from a shipping channel? When these animals were alive, the sea levels were much lower, so the area was above water back then.

The most interesting features on this coprolite are the bite marks on the surface. Scientists refer to these as feeding or grazing traces. The small parallel lines were left by small animals when the poop was fresh. We don't know if the trace makers were feeding on the feces or feeding on what was growing or feeding on the feces. Say that three times fast! One of the larger traces appears to have been made by a fish after the fecal matter was fossilized. The way we can tell it was made after fossilization is the darker coating that formed on the surface of the coprolite is missing in this area, and the surface of the trace is rougher than what would have been if formed when the feces was fresh. Parrotfish have been known to make "grazing scars" on coral that resemble that left on the coprolite. Some species of parrotfish feed on algae and other animals that grow on rocks and dead corals. This coprolite has remnants of encrusting bryozoans and barnacles that formed on its surface while it was underwater. So we know that it was exposed on the sea floor prior to being dredged up and placed on land.  

While this coprolite does have some bone inclusions, the prey cannot be identified. Based on the shape, age and location of this coprolite, it was likely left by a canid (wolf) or felid (cat).  

Found by George Wolf (10/01/1935 to 11/18/2017) of Pasadena, Texas.