November 17, 2010

Geology Word of the Week: C is for Coprolite

Posted by Evelyn Mervine

A coprolite. Image courtesy of USGS, taken from Wikipedia commons.

def. Coprolite:
1. Fossilized animal dung. That’s right, rock solid animal poop.
2. Something I occasionally find under the sofa next to my cats’ litter box. Thanks, Samira and Zayna, you little furballs.

I have actually never seen a genuine coprolite. The “cat coprolites” I sometimes find are not true fossils- they’re dried out, but their structure hasn’t been replaced with silicates and calcium carbonates. I would like to see a real coprolite, or several. If anyone knows of a good museum displaying these, let me know, and I’ll try to plan a vacation there at some point. That’s right, I will include “go see fossilized poop” on my vacation agenda. Why? Because coprolites are pretty cool, when you think about it. I find it amazing that poop can become fossilized and that, millions of years later, geologists can recognize fossilized poop and learn things from it.

Coprolites are one of many trace fossils. A trace fossil is a fossil which does not preserve the animal itself (well, unless you count poop as part of the animal…) but rather preserves traces of animal life.  Other types of trace fossils are footprints, burrows, borings, feeding traces, and resting traces. Coprolites and other bromalites (see below) are important because from these fossils we can learn about the bodily processes of ancient animals and humans. Millions of years ago, animals and humans were just as gross as they are today: they pooped, peed, and vomited. In lucky cases where these bodily excretions were fossilized, we can learn much about the biology of ancient organisms- what they ate, where they ate, where they peed, where they pooped, and so on.

Here are a few other awesomely gross trace fossil words:

Bromalite: a general term used to describe any kind of fossilized remains from the digestive system of an animal or human.

Urolite: trace fossil preserving erosion caused by peeing. Did you know that dinosaurs peed?

Paleofeces: fossilized human (distinguished from animal) poop.

Regurgitalite: fossilized vomit or other regurgitated material (such as stones to aid digestion).

Cololite: fossilized intestinal contents.

Gastrolite: fossilized stomach contents.

And, here are my two little coprolite producers: