As every researcher knows, a sample size of one is a dangerous thing. A single example might represent something very common, albeit as yet unconfirmed, or it might be just an oddity.
This is the dilemma faced by researchers led by anthropologist Elanor Sonderman of Texas A&M University in the US, and outlined in a paper published in the Journal of Archaeological Science: Reports.
Sonderman’s team deliver a detailed analysis of an ancient human coprolite – that is, fossilised faeces – discovered at a pre-Columbian Texas archaeological site called Conejo Shelter.
Coprolites, from any species, are extremely valuable to scientists from many disciplines, because analysing their contents provides important clues about diet.
Based on radiocarbon dating of a second poo found in close proximity to the one in question, the researchers estimate that their sample has been present at Conejo for between 1460 and 1528 years.
For the most part, it comprised material that matched those of other samples unearthed in the region surrounding the site, known as the Lower Pecos.
It included remnants from a common agave species, Agave lechuguilla; a number of species from the genus Dasylirion, relatives of asparagus; and a cactus genus called Opuntia, more commonly known these days as prickly pear.
There were also some bones from a small rodent, which was, the researchers write, “evidently eaten whole, with no indication of preparation or cooking”.
What was extremely interesting, however, and to date unique, was the presence of bones, scales and an entire fang of a snake from the family Viperidae.
The discovery, Sonderman and colleagues write, “is the first direct archaeological evidence of venomous snake consumption known to the researchers”.
Thus, the dilemma inherent in the sample size of one. At present there is simply no way of knowing whether the long-distant residents of the Conejo Shelter opted to devour whole, raw venomous snakes, let alone whether they did so for cultural, religious or simply nutritional purposes.
The single piece of ancient faeces may in fact represent nothing more than the after-effects of a lone resident who decided on a whim to see what snake tasted like and then decided never to repeat the experiment again.
Sonderman and colleagues recommend further investigation of coprolites from the same area and time period in order to add context to “this unique gastrological event”.