Catherine Dupont

From Harvesting the Sea to Stock Rearing Along the Atlantic Façade of North-West Europe

Abstract By 3000 BC, farmers had settled most of the small islands of north-western Europe. This implies the transportation of domestic animals by sea, sometimes over long distances, and the adaptation of herding techniques to new marine environments. While many of the same islands were in use in the Mesolithic period, the nature and extent of this use appears to have been quite different. Zooarchaeological and stable isotopic analysis converge to suggest that the diet of human communities at this time was heavily reliant on marine foods. Neolithic settlements located in the same setting offer a contrasting view. Shell middens were still present at this time, and the remains of fish, marine birds and sea mammals confirm that marine resources were still exploited, but isotopic evidence highlights their minor contribution to the diet. This, combined with the faunal dominance of cattle, sheep and pig, indicates a reliance on domesticated resources. By the end of the Neolithic, even the most peripheral islands of north-western Europe were being exploited primarily for their terrestrial resources. This paper presents evidence from selected sites in western France and Orkney, and then proceeds to offer some possible explanations for the observed patterns of small island use in the Neolithic.

Coastal exploitation in the Mesolithic of western France: la Pointe Saint-Gildas (Préfailles)

Abstract Following surveys carried out over many years, three Mesolithic sites have been identified at the ‘Pointe Saint-Gildas’ near the Loire estuary. They are situated in proximity to more than 20 indications of the presence of Mesolithic populations. Two of the three excavated stations provide the only evidence of the subsistence of these Late Mesolithic populations. These excavations were carried out in 1994 at station 1a, and in 2003 and 2004 at station 1b, and revealed a lithic industry based on blades and small concentrations of shells. The dominant arrowhead types are large scalene triangles, but with some asymmetrical trapeze-shaped points. They are associated with industries based on blades and bladelets with non-parallel edges. The analysis of shells indicates the exploitation of resources on a muddy shore, whereas these sites currently overlook a rocky zone. The Holocene transgression has masked the trace of a noticeable estuarine influence, according to studies of the bathymetry and underwater sedimentary cores. Dating of the shells yields ages between 6600 and 6400 BC at Saint-Gildas 1b. The marked deterioration of these sites by erosion and the inaccurate calibration of the dates lead to uncertainties in the interpretation. Nevertheless, these assemblages are the first example of the emergence of Late Mesolithic industries on the Armorican Massif.

Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past

Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo‐) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro‐) structure and biogeochemical composition. Adding to this list, the DNA entrapped in shell carbonate biominerals potentially offers a novel and complementary proxy both for reconstructing palaeoenvironments and tracking mollusc evolutionary trajectories. Here, we assess this potential by applying DNA extraction, high‐throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome‐scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine environment. Finally, we reconstruct genomic sequences of organisms closely related to the Vibrio tapetis bacteria from Manila clam shells previously diagnosed with Brown Ring Disease. Our results reveal marine mollusc shells as novel genetic archives of the past, which opens new perspectives in ancient DNA research, with the potential to reconstruct the evolutionary history of molluscs, microbial communities and pathogens in the face of environmental changes. Other future applications include conservation of endangered mollusc species and aquaculture management.

The Dog Whelk Nucella lapillus and Dye Extraction Activities From the Iron Age to the Middle Ages Along the Atlantic Coast of France

ABSTRACT In Europe, the extraction of dyes from marine shells found in archaeological contexts is little known outside the Mediterranean area. Although smaller than the Mediterranean species with dyeing properties, the dog whelk Nucella lapillus and the oyster drill Ocenebra erinaceus can be indicative of dyeing activities. They are regularly found broken in archaeological contexts in France and Ireland, where their presence can indicate an important economic activity of the coastal inhabitants. In this article, I summarize the archaeological data for this activity along the Channel and Atlantic coasts of France, including localization of these deposits and their chronology, composition of the shell middens, typology of fragments of shell, and presence of other activities. The application of biometrics to dog whelks from one site, ZA du Pladreau, yields information on the way in which the shells were selected first on the seashore, and second at the place of pigment extraction.