Fluted point manufacture in eastern North America: an assessment of form and technology using traditional metrics and 3D digital morphometrics

Differences in Paleoindian projectile point morphology have previously been used to define technologies, infer colonization patterns, propose chronological and regional boundaries. In this study, we evaluate the effectiveness of traditional linear measurements and ratios, flake scar angles, and 3D model-based flake contours for the statistical differentiation of projectile point type(s) and reduction technique. Sixty-three fluted bifaces from eastern North America and fourteen replicate Clovis points are analyzed. Discriminant analysis shows that 3D model-based Fourier descriptors of flake scar contours are less successful than traditional metrics in correctly differentiating styles, but more successful in identifying individual knappers. Changes in the symmetry of front and back flake scars between Clovis and later fluted point styles indicate a possible shift in reduction techniques. These findings demonstrate the usefulness of both traditional and modern morphometric variables to quantify biface morphology, and address questions about social interaction and technological change in Pleistocene North America.