High handaxe symmetry at the beginning of the European Acheulian: The data from la Noira (France) in context.

Radu Iovita,Marie-Hélène Moncel,Inbal Tuvi-Arad,Jackie Despriée,Jean-Jacques Bahain,Pierre Voinchet,Nuno Bicho

doi:10.1371/journal.pone.0177063

Abstract

In the last few decades, new discoveries have pushed the beginning of the biface-rich European Acheulian from 500 thousand years (ka) ago back to at least 700 ka, and possibly to 1 million years (Ma) ago. It remains, however, unclear to date if handaxes arrived in Europe as a fully developed technology or if they evolved locally from core-and-flake industries. This issue is also linked with another long-standing debate on the existence and behavioral, cognitive, and social meaning of a possibly chronological trend for increased handaxe symmetry throughout the Lower Paleolithic. The newly discovered sites can provide a link between the much older Acheulian in Africa and the Levant and the well-known assemblages from the later European Acheulian, enabling a rigorous testing of these hypotheses using modern morphometric methods. Here we use the Continuous Symmetry Measure (CSM) method to quantify handaxe symmetry at la Noira, a newly excavated site in central France, which features two archaeological levels, respectively ca. 700 ka and 500 ka old. In order to provide a context for the new data, we use a large aggregate from the well-known 500 ka old site of Boxgrove, England. We show that handaxes from the oldest layer at la Noira, although on average less symmetric than both those from the younger layers at the same site and than those from Boxgrove, are nevertheless much more symmetric than other early Acheulian specimens evaluated using the CSM method. We also correlate trends in symmetry to degree of reduction, demonstrating that raw material availability and discard patterns may affect observed symmetry values. We conclude that it is likely that, by the time the Acheulian arrived in Europe, its makers were, from a cognitive and motor-control point of view, already capable of producing the symmetric variant of this technology.

Highlights

From the very beginning of their first discovery in the 19th century [1], handaxes have been the subject of extraordinary fascination, a fact that has led to some very rigorous research on the objects themselves, and to much speculation about their social and even biological meaning [2,3]
We present Elliptical Fourier (EF) shape data and Continuous Symmetry Measure (CSM) data on handaxe contours from the site of Brinay la Noira, contextualized by technological and raw-material studies, as well as comparative data from another key site, Boxgrove (England)
The main result of our analyses is that handaxes from the lower layers at la Noira, which are at least 700 ka old, already exhibit a high degree of longitudinal symmetry that is largely invariant of a variety of factors usually thought to affect the ability of prehistoric hominins to work stone, such as raw material quality and reduction technique, as well as reduction stage

Summary

Introduction

From the very beginning of their first discovery in the 19th century [1], handaxes have been the subject of extraordinary fascination, a fact that has led to some very rigorous research on the objects themselves, and to much speculation about their social and even biological meaning [2,3] Much of this fascination has to do with our perception of these objects as intentionally ’well-made’, ’symmetric’, or ’beautiful’ [4], and as an index of the hominins’ aesthetic appreciation [5] and cognitive [6,7] abilities. An opposing, yet diverse collection of views, holds that such a trend is nonexistent [17,18], or that, if it exists, it reflects either non-intentional cultural practices, such as copy-error [19,20,21] or functional constraints on tool shape [22], life history of the tool or geometric constraints due to raw material choices [23], rather than cognitive differences

Methods

Results

Conclusion