title: Changing collecting strategies of the clam Donax serra Röding (Bivalvia: Donacidae) during the Pleistocene at Pinnacle Point, South Africa.
abstract: South Africa's Middle Stone Age (MSA) coastal sites have played a prominent role in documenting early evidence of systematic shellfish collection and adaptation to aquatic environments in the context of anatomically modern humans. Pinnacle Point 13B cave is important among these MSA sites not only because it holds the earliest yet known evidence for human use of marine resources (∼162 ka [thousands of years ago]), but because shellfish observations have been integrated more fully into discussions of MSA adaptations. This is particularly the case of Donax serra procurement on sandy beaches, where skills that are usually indicative of an aspect of behavioural modernity (in the context of hunting) were apparently used. In this paper, D. serra from 110 to 91 ka old assemblages are studied in detail by way of metrical analyses and relevant biological and ecological literature of this species. Existing seasonality studies derived from oxygen isotope analyses on the same molluscs are incorporated into this reconstruction. Shellfish appear to have been collected in winter over many millennia when D. serra are most nutritious due to high gonad content. A dramatic change in collection strategies took place during the same millennia-long period. Earliest systematic collection of D. serra consisted of mostly unselective procurement of animals in terms of shell size along the tidal gradient and beach depth. In later visits, people collected mostly larger individuals by narrowing their collection to the mid-intertidal. This change increased the efficiency of D. serra collection, which reflects a positive adaptive behaviour that endured into Later Stone Age (LSA) times.
authors.affiliation: Department of Archaeology and Anthropology, ICREA & Spanish National Research Council (CSIC-IMF), C/de les Egipcíaques 15, Barcelona 08001, Spain. Electronic address: a.jerardino@imf.csic.es.
authors.forename: Antonieta
authors.initials: A
authors.lastname: Jerardino
authors.affiliation: Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa. Electronic address: rene.navarro@uct.ac.za.
authors.forename: René A
authors.initials: RA
authors.lastname: Navarro
authors.affiliation: Department of Archaeology, University of Cape Town, Rondebosch 7701, South Africa. Electronic address: mgrazia.galimberti@gmail.com.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Galimberti
mesh_terms: D000704:Analysis of Variance; D060105:Animal Shells / Q000033:anatomy & histology*; D000818:Animals; D000885:Anthropology, Physical; D049872:Bivalvia / Q000033:anatomy & histology*; D005247:Feeding Behavior / Q000502:physiology*; D005580:Fossils; D006801:Humans; D013019:South Africa
keywords: Middle Stone Age; Mossel Bay; Sand beaches; Shell midden; Shellfishing