Remains of Tunisian snails provide insight into possible 7,700-year-old local food tradition

A new study by Dr Ismail Saafi of Aix-Marseille University provides details on the discovery of cooked snail remains in Kef Ezzahi, northern Tunisia. The snail remains, dating back approximately 7,710 years, are the only known cases of snail remains in North Africa with their epiphragms (temporary closing membrane) intact.

The results raise questions and shed light on the consumption of snails and the antiquity of culinary traditions in Tunisian societies. The results are published in the journal Archaeological and anthropological sciences.

The Kef Ezzahi site is one of the rare sites that contain a rammadiyet (massive accumulations of shell remains). During excavations carried out at the site in 2012, shells belonging to the species Sphincterochila candidissima were discovered. Among these more than 35,000 remains, 41 revealed the presence of epiphragms.

Dr Saafi explains the function of this epiphragm: “Land snails produce an epiphragm when climatic conditions are unfavorable for their activity (temperature varies between 5° and 25°, presence of rain or high humidity). The epiphragmum protects against water loss, in particular. when the temperature increases. »

This discovery is notable because it is the only known case in North Africa and may be one of the oldest pieces of evidence indicating humans consuming epiphragm snails.

“In Turkey, shells of Pomatias elegans with an epiphragm were discovered at the site of Cave I of Üçağizli (41,000-29,000 BP uncalibrated). The presence of a perforation in the middle of the epiphragm of a shell encourages researchers to consider consumption of the flesh by a predator. It is therefore not a collection intended for consumption,” explains Dr Saafi.

“So far, the discovery at Kef Ezzahi constitutes the oldest evidence of collecting epiphragm-bearing land snails in relation to consumption.”

To understand why epiphragm snails may be so rare in archaeology, Dr. Saafi conducted an ethnographic study of a modern population living in Aouled Said.

The inhabitants of Aouled Said (or Saâïd) harvest Cantareus apertus, a snail which also produces epiphragms. His study found that individual families and groups in Tunisia collect only certain species of snails, usually based on their size and taste.

The group living in Aouled Said began collecting Cantareus apertus snails, which are only found in northern Tunisia. In summer, these snails enter a period of aestivation (a resting period similar to hibernation). During this time, they burrow underground and create an epiphragm.

Snail collectors should harvest the snail in summer, between April and July. To do this, collectors use pickaxes to dig the ground. Once collected, the snails should be placed in a container filled with ash or sawdust, otherwise the snail will lose its epiphragm.

Any snails that lose their epiphragm or do not have one are discarded or avoided because they are considered dirty. It is imperative to collect the snails at the right time; if they are left in their resting phase for too long, they become bitter and their mass decreases, making them less suitable for the market or consumption.

On average, collectors are able to collect around 1 kg of snails in a single day, leaving behind the juveniles to ensure the survival and abundance of the species for the following season. Due to the intense physical activity required to collect these snails, it is generally a task reserved for men or young people over the age of 15. The skill and know-how of this collection technique are passed down from generation to generation. .

The absence of epiphragms in other archaeological contexts is unlikely to constitute a preservation bias. Indeed, although easy to remove, once in the archaeological deposit, the epiphragms remain relatively unchanged.

According to Dr. Saafi, “An epiphragm may be best preserved when it is still stuck to the shell entrance. Once the shell is buried in the archaeological deposit (mainly ashes in the case of our study sites), the modifications are less significant (except in the case of contact with another harder archaeological object (flint or stone)).

Instead, their rarity in archeology is likely related to the difficulty of obtaining them. As the ethnographic study shows, it takes a unique set of skills to know where to look for snails with epiphragms and when to collect them. Additionally, the physical effort required and limited collection season may make them less desirable as collection targets compared to other snails, which may be more widespread and can be collected year-round in greater quantities.

Dr Saafi says: “This rarity could be due to a culinary tradition that was not popular with ancient populations. To eat the shells, the epiphragm must be removed to extract the body of the mollusk from its shell. Thus, this rarity is more linked to culinary practices (collection and consumption) than to a conservation bias.”

It is possible that a group of prehistoric Tunisians practiced collecting S. candidissima, in the same way that modern groups in Tunisia specialize in collecting one type of snail species. A transmission of this technique from generation to generation, as evidenced by the fact that the S. candidissima snails, which constitute 90% of the snail species of Kef Ezzahi, are found throughout the deposit, suggesting its continuation of collection over time. time.

However, due to the limitations of collecting this species, other groups and sites with shell remains have not adopted the collection of S. candidissima or other epiphragm-producing snails, hence their rarity in archaeology.

“This discovery confirms the antiquity and continuity of certain practices linked to culinary and cultural traditions in the exploitation of land snails, such as the extraction of the bodies of molluscs after piercing the shell. These data allow us to better understand the state of land snails. land snails among ancient and contemporary populations,” explains Dr. Saafi.

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