Shell middens are archeological features consisting mainly of the remains of marine animals thrown away near settlements over hundreds or thousands of years. They are the debris of human activity. In Brazil, they are known by the Tupi word sambaqui.
The sambaquis were left by people who lived between 8,000 and 1,000 years ago in coastal Atlantic Forest areas, traditionally considered peripheral to South America’s first food production centers in the Andes and the Amazon.
A new study, however, presents strong evidence that sambaqui societies were not ordinary hunter-gatherers. Analysis of their middens shows that they cultivated or at least managed edible plants and had a rich diet with a substantial proportion of carbohydrates. Fapesp — São Paulo Research Foundation- FAPESP has supported the study.
Findings from the study have recently been published in Royal Society Open Science. It was conducted by researchers from Brazil and the United Kingdom using data collected at the Morro do Ouro and Rio Comprido sambaquis in Babitonga Bay near Joinville, Santa Catarina State.
“The significant levels of consumption of high-carbohydrate foods evidenced by these two sambaquis suggests the communities had a mixed subsistence economy that combined fishing and the collection of seafood with some form of plant cultivation,” said Luis Nicanor Pezo-Lanfranco, a bioarcheologist at the University of São Paulo’s Bioscience Institute (IB-USP), first author of the article and a FAPESP grantee.
Pezo-Lanfranco conducted the study at IB-USP’s Biological Anthropology Laboratory, led by Professor Sabine Eggers, in partnership with archeologists at the University of York (UK) and Joinville’s Sambaqui Museum.
According to the traditional archeological view of prehistory in South America, the hunter-gatherers who left the shell middens maintained themselves mainly by foraging marine resources. This idea began to be contested in the 1980s when evidence was found that the sambaqui societies had a far more diversified economy.
The high frequency of sambaquis on the southern coast of what is now Brazil and the large volume of some of these shell middens, which also contain hundreds of human burials, are considered evidence of high population density, monumental architecture, and social complexity during the Middle to Late Holocene.
Dental caries on the teeth of buried skeletons, interpreted as evidence of a high-carbohydrate diet, are among the reasons for concluding that these communities had a more diversified economy and diet than previously believed.
Moreover, archeological digs have identified remains of plants that may evidence incipient cultivation of food crops, including tubers (yam and sweet potato), corn, palm trees, soursops and sweetsops (Annonaceae).
The new study was based on oral pathology and stable isotope analyses performed directly on the skeletons. The analyses revealed unexpectedly high consumption of plant resources, i.e., carbohydrates, by the Morro do Ouro sambaqui people on the northern coast of Santa Catarina in the…