Mesolithic to Neolithic Transitions: New Results from Shell-Middens in the Western Algarve, Portugal. (Research)
Stiner, Mary C., Bicho, Nuno F., Lindly, John, Ferring, Reid, Antiquity
The Algarve shell-midden sites span roughly 9500 to 6500 years before the present and represent the Mesolithic and early Neolithic cultural periods (Table 1). All of the Algarve middens to be discussed contained fire-cracked rock, and some of them have ceramics in the upper layers. Traditionally, archaeological sites in Portugal are classified as Neolithic if ceramic sherds are present, following the guidelines applied elsewhere in Europe. This zoo-archaeological study of the shell middens in the western Algarve region of Portugal questions the nature of the Mesolithic-Neolithic economic transition. Does the appearance of ceramics correspond to the adoption of agriculture or livestock herding? Or did hunting and gathering continue in this area, with the minor addition of utilitarian ceramic vessels to local tool kits? Shellfish exploitation was one aspect of Mesolithic and early Neolithic subsistence in the Algarve, but the perennial importance of marine resources here suggests that the malacofaunas can register important shifts in subsistence organization, regardless of whether shellfish were primary or "fall-back" sources of animal protein, fats, and other nutrients. The nutritional rewards of some shellfish are considerably greater than those of many terrestrial wild animals, such as hares, the latter having been heavily exploited at some inland sites in Portugal during the later Palaeolithic (e.g., Hockett & Bicho 1999; see also Hockett & Haws 2001).
Several shell middens were identified by the authors during surveys of the western Algarve, and those tested between 1997 and 1999 yielded the collections used in this paper. All of the sites lie west of Faro (Figure 1), most within a few hundred meters of the modern Atlantic shore, often perched on limestone coastal cliffs 10 to 60 m above sea level with access to rocky collection areas below (Figure 2). Rocha das Gaivotas (Mesolithic) and Vale Santo I (early Neolithic) occur in sand dunes and near good flint sources; the former lies on the modern coastline and the latter 1 km inland. At Barranco das Quebradas II and I another coherent but somewhat older faunal series occurs in collapsed rockshelters along a narrow valley, a few hundred meters from the Atlantic shore and adjacent to a fresh water spring. Ribeira de Alcantarilha, an early Neolithic occupation, is located on a high clay terrace of a river valley, now 5 km inland, although it must have been on an estuary at the time of occupation. In contrast to the other shellmidden sites, Ribeira de Alcantarilha is associated with shorelines dominated by soft-sediments and the mollusc species in this midden vary accordingly.
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Virtually all the faunal remains in the Algarve middens are from marine molluscs. The sediment chemistry of these sites would seem suitable for bone preservation, as the shells are in good condition, leaving us with the conclusion that bones were seldom deposited. The shellfish were definitely collected by humans (see below) and nearly all of them (>99%) were consumed as food; shell ornaments are present but rare. The genera commonly exploited (Table 2) have similar adult soft tissue weight ranges, if scaled to human dietary need, and most of the genera inhabit the rocky intertidal zone: mainly mussels (Mytilus), limpets (various Patella species and, rarely, Siphonaria), turbans (Monodonta), and a large drill known as Thais haemastoma. At Ribeira de Alcantarilha, by contrast, carpet venus clams (Ruditapes decussatus) were particularly important, supplemented by other soft-substrate species such as cockles (Acanthocardia tuberculatum and Cerastoderma edule), scallops (Pecten maximus), bittersweets (Glycymeris sp.), striped venus clams (Chamelea gallina), and razor clams (Solen sp. or Ensis sp.). Thais occurs on a wide range of substrates but is much more common on rocky shores.
These shellfish represent significant sources of fat and carbohydrates in autumn, winter, and particularly spring (Fernandez-Reirez et al. …