The word coprolite is a scientific way of saying ‘dry dung’. Like so many other archaeological terms, the name coprolite is derived from the two Greek words kopros translated ‘dung’ and lithos meaning ‘stone’.
Coprolithic products are an important source of information in archaeology and form its own classification in the more specialised field of palaeontology.
Simply put coprolites are the preserved faeces of animals and humans. These fossilised faeces are the delight of coprolite analysts who gleefully bring them back to their former soft, smelly forms and picking them apart to see what its owner once had for breakfast.
Dr Eric Callen, a botanist with no archaeological background, is credited with the distinction of being the scientific founding father of studying faeces. It was his process that brought large lumps of fossilised excrement back to life.
In All Shapes and Sizes
Coprolites are often found at archaeological excavation sites. Typically they have been excreted by medium to large sized animals including humans. However, smaller animals do leave deposits and very tiny mounds of excreta have been collected from worms.
The shape of the coprolite is dependant upon the animal that ejected it. A common form is cigar-like but a great variety of shapes exist including cylinders, spirals, cones, flat rounds and ovals.
What’s in the Dung?
Fresh animal or human excrement rapidly deteriorates and is particularly vulnerable to water damage so finding fossilised remains in good condition is a valuable discovery. The archaeologist is especially interested in the composition of human coprolites as this often assists in providing meaningful information about human diet and possibly the overall health of a community.
The Method of Softening
The technique of coprolite analysis begins by first rejuvenating the dry lifeless faeces into a soft pliable substance. This is achieved by soaking the dung ball in a special solution. Unfortunately, reconstitution has the added bonus of also resurrecting its former smell.
Once the fossil has been softened its composition can be scrutinised. In the macrobotanical laboratory experts will be searching for the evidence of seeds and charcoal while other scientists will hunt for bone fragments or even spores and pollen.
What Was On the Menu?
Macrobotanical remains are the most reliable in attempting to reconstruct the diet of the subject. Seeds and plant residues can guide the researcher to understand the diet in terms of food type, variety and quantity. Dietary comparisons with other coprolites may permit the identification of differences in class or social status. Studying the coprolites of a community may shed light on their economic situation and the possibility of food trading.
Traces of carbon in the coprolite almost always tend to suggest that the food was cooked although in some rare instances carbon may have been deliberately ingested for medicinal reasons. The evidence of carbon in early human diets is of considerable importance as it is assumed that ‘primitive man’ ate only raw fruits and vegetables.
How Long Between Dumps?
Each human coprolite is a short time capsule in the life of an ancient person. There are varying theories on just how long one coprolite covers. Some suggest a 24-hour period based on one faecal excretion per day. Others propose a much longer period, even up to three or four days, based on the view that most ancient cultures did not eat to excess and therefore a subsistence diet may return irregular movements. Those who feel that poor sanitation would have created chronic dysentery and most ingested foods would have been excreted within hours counter this view.
Whatever the time period actually covers is open to speculation but there is no guesswork about the seeds and plant produce found, which can be analysed to not only identify species eaten, but can determine food preparation methods and the relative health of a community, by evaluating the nutritional vitamin and mineral contents in the biological remains.