a1 Centre national de la préhistoire, ministère la culture, et de la communication, Univ. Bordeaux, CNRS, PACEA, UMR 5199, F-33400 Talence, France Email: [email protected]
a2 School of Geography and Environmental Science, Monash University, Clayton, Victoria 3800, Australia Email: [email protected]
a3 Univ. Bordeaux, CNRS, PACEA, UMR 5199, F-33400 Talence, France Email: [email protected]
a4 EDYTEM - UMR 5204 du CNRS, Environnements, Dynamiques et Territoires de la Montagne, Centre Interdisciplinaire Scientifique de la Montagne, Université de Savoie F 73376, Le Bourget du Lac Cedex, France Email: [email protected]
a5 Radiocarbon Dating Laboratory, University of Waikato, Hamilton, 3240, New Zealand, Email: [email protected]
The grinding of stone to make sharp cutting edges did not evolve with the emergence of biologically modern humans in Africa, but late in the Pleistocene at the completion or nearcompletion of the Out-of-Africa 2 migration. Here we discuss the earliest securely-dated fragment of ground-edge axe from Australia, dated at 35,500 cal. bp, an age slightly older or comparable to the earliest ages for edge-grinding from the Pacific Ocean's western seaboard. In this region ground-edge axes did not evolve with the emergence of agriculture, nor for the clearance of forests, but, rather, as socially mediated technology, part of the development of symbolic storage that is the hallmark of the evolution of cognitively modern humans at the geographical end, during, or following, Out-of-Africa 2.
(Received April 13 2011)
(Accepted September 02 2011)
(Revised August 10 2011)
Professor Jean-Michel Geneste manages France's primary national rock-art research institution, the Centre National de Préhistoire, and directs the Chauvet Cave International Research Program. He has been Curator of Lascaux for more than 20 years and is a Field Director and Research Coordinator on the ‘Connecting Country Jawoyn Homeland Archaeological Project’ (connectingcountry.arts.monash.edu.au).
Dr Bruno David specializes in the archaeology of the Sahul region. He works with Indigenous communities on the archaeology of rock art and symbolic expressions, tracking the origins and transformations of ethnographically documented cosmological and social traditions back in time by investigating temporal and formal discontinuities in their material signatures. He is Project Co-ordinator and Field Director on the ‘Connecting Country Jawoyn Homeland Archaeological Project’.
Dr Hugues Plisson specializes in use-wear analysis of prehistoric tools. His methodology, based on a synthesis of the Western and Russian schools, has influenced generations of researchers aiming to understand the function of archaeological objects.
Professor Jean-Jacques Delannoy is a geomorphologist and Director of the EDYTEM research laboratory. He is Professor at the Université de Savoie where he teaches karst systems. His work crosses geomorphological and archaeological data to better understand site-formation processes.
Dr Fiona Petchey specializes in the reliable radiocarbon dating of a range of objects including charcoal, shell, pollen and bone. She oversees the pretreatment of small samples for AMS processing.