Size and shape variation in Late Holocene projectile points of southern Patagonia. A geometric morphometric study

CHARLIN, J. Y R. GONZÁLEZ-JOSÉ

American Antiquity

Society for American Archaeology

Año: 2010

0002-7316

Since the beginning of systematic archaeological studies in southern Patagonia (Argentina and Chile), projectile points have played an important role as cultural markers. Using a sequence of projectile point types differentiated according to size and shape changes, these stone tools, along with other cultural evidence, were used to distinguish a series of “cultural periods” that have been the frame of reference for understanding the cultural evolution in southernmost Patagonia. Although later research have questioned several of the assumptions used in creating this framework, the classical typology of projectile points continued in use until the present day. The goal of this study is to evaluate size and shape variation of two late Holocene projectile point types, known as Fell-, Bird- or Magallanes-IV and V points, or Patagónicas and Ona points, respectively. We compared both point types using geometric morphometrics and multivariate statistical analyses. Our focus is on the reliability in the discriminating between point types in light of point reduction due to maintenance and use. These analyses show reduction has a major impact on shape rather than on size, and on the blade rather than on the stem. Importantly, point types IV and V can still be distinguished in terms of size and stem shape despite reduction. Thus, while successive cycles of use, damage, and resharpening can have a great influence over the size and shape of projectile points, resharpening techniques are specific enough to maintain differences in size and shape between point types, and is probably related to functional requirements.