Coprolite

Object: Coprolite
Date: 4250-4750 BC (6200-6700 years ago), late Early Archaic period
Context: Lower Pecos Canyonlands, Hinds Cave, Area B, Analysis Unit 5d, Lens 13

Though homely, this desiccated human fecal specimen makes up for in scientific substance what it lacks in looks. This coprolite was excavated during the 1975-1976 field seasons at Hinds Cave, a dry rockshelter situated high in a limestone cliff in the Lower Pecos Canyonlands of southwest Texas. Sample 87 was one of several hundred coprolites excavated from a latrine area along the back wall of the rockshelter—Lens 13. For her dissertation at Texas A&M University, archeologist Glenna Dean (then Williams-Dean) analyzed one hundred coprolites from Lens 13 including this one, the remainder of which is curated at Texas A&M University.

The story of TAMU's archeological investigations at Hinds Cave is told elsewhere on TBH (see Hinds Cave: A Perishable Scientific Treasure, including a site map and a description of the Area B excavations, where the latrine was documented. For an overview of Glenna Dean's research see Lab Research Results.

The Sample 87 coprolite provides direct evidence of the gastronomical choices of a Lower Pecos individual over several days. It also reflects the season in which these choices were made, simultaneously illuminating the timing of habitation of Hinds Cave. More broadly, Sample 87 and the other Lens 13 coprolites reflect the climate and ecology of the Lower Pecos Canyonlands 6000-7000 years ago at the end of the Early Archaic period.

Upon analysis of the contents of Sample 87, Williams-Dean found the coprolite contained at minimum eight different plant and animal species. Identified plants include cactus (Opuntia), walnut (Juglans), mesquite (Prosopis), onion (Allium) and agave (Agave). Animal remains include packrat (Neotoma) and cotton rat (Sigmodon) bones as well as fur. Needless to say, the method of ingesting animal protein adopted by ancient Lower Pecos people was markedly different than the method most of us enjoy today. Many coprolites show that small game was frequently eaten without gutting, deboning, or cooking—“grab it and gulp,” so to speak. In a similar fashion, plants such as walnuts and mesquite beans were sometimes crushed and eaten shell and all.

In terms of seasonality, some of the rodent bones from Sample 87 were unfused, indicating the rodents consumed were juveniles. Given that packrat and cotton rats typically give birth in the spring and summer, it is likely that Sample 87 was deposited during these warm seasons. Plant pollen identified in the Lens 13 coprolites also support this hypothesis.

Insects were also found in Sample 87, including the remains of a spider beetle (Niptus abstrusus) and fly (Diptera). These two insect species are coprophagous (feces eating) and likely were attracted to the latrine area. That said, other insect species were certainly part of the Lower Pecos diet and Sample 87 contained unidentified invertebrate remains which may include intentionally eaten insects.

Williams-Dean described the form of Sample 87 as coiled, indicating a softer stool, though not so soft as to be diarrheic. Very soft forms might indicate illness, consumption of laxative plants, or contaminated drinking water. Williams-Dean analyzed 12 coprolites for evidence of intestinal parasites and found none. However, she unexpectedly found an algae diatom and skeletons in several coprolites. These algae were likely imbibed in water collected from small ponds formed in natural bedrock catchments near the rockshelter, a hypothesis supported by identification of the same algae species living in these tinajas during the Hinds Cave excavations.

The evidence is fragmented, and scattered over 6000 years of coprolites, bones, Spanish records, and ranchers' boyhood memories, but the evidence all suggests to the same type of general landscape: increased soil cover supporting grassland vegetation on the uplands with water present in potholes and agave and prickly pear cactus available, and rocky, rugged canyons probably covered with woody scrub vegetation similar to that found today. — Glenna Williams-Dean (1978)

Much more information can be gleaned from coprolites than is presented here: human DNA and DNA from the consumed plants and animals can be obtained from coprolitic material, hormones can point to the sex of the individual who deposited the coprolite, and viruses can and have been found—such as an ancient but biologically viable virus identified in another Hinds Cave coprolite. Of course, coprolites can also be directly radiocarbon dated. Other microscopic fractions, such as plant phytoliths and grit from food processing with groundstone tools, can also sometimes be identified.

The analysis of Sample 87 and other coprolites from Lens 13 beg additional questions: Why were people ingesting hard, sharp, largely indigestible materials like bone and walnut shell? Why was the latrine inside the shelter, and what effect did this have on health and hygiene? What was the culture of eating—were meals communal, did people “grab it and gulp” as they foraged, or both?

As demonstrated by Sample 87 from Hinds Cave, the breadth of archeological and environmental information that can be gleaned from coprolites makes excellent food for thought.

Credits

Authored by TBH Editorial Assistant Emily McCuistion. Thanks are extended to Nicholas Bentley at Texas A&M University Anthropology Research Collections for confirming the location and status of Sample 87 at the time of writing (summer 2020).

Print Source

Williams-Dean, Glenna
1978   Ethnobotany, and Cultural Ecology of Prehistoric Man in Southwest Texas. Ph.D. dissertation, Department of Anthropology, Texas A&M University. Published by the department in an unnamed report series, here termed Hinds Cave Report 2.