Journal of Archaeological Science 131 (2021) 105359 Available online 28 May 2021 0305-4403/© 2021 Published by Elsevier Ltd. Measuring allometry in dimensions of western North American Clovis points Michael J. Shott a , Justin P. Williams b, * , Alan M. Slade c a Department of Anthropology, University of Akron, Akron, OH, 44325, USA b Department of Core Curriculum, Roger Williams University, Bristol, RI, 02809, USA c Texas Archaeological Research Laboratory, University of Texas at Austin, Building 5C, 10100 Burnet Rd, Austin, TX, 78758, USA A R T I C L E INFO Keywords: Clovis Allometry Resharpening Paleoindian Curation Reduction ABSTRACT Paleoindian Clovis points are a well-studied type whose size and shape at frst use are reasonably documented. Yet Clovis points probably suffered damage and experienced reduction in use. Points are divisible into modules, which may have undergone different degrees of reduction, generating allometry—changing shape with changing size—distinct from original size and shape. Recognizing allometry improves typological assignment, measures curation and gauges prehistoric behavior against theoretical models. Bivariate and multivariate tests of linear dimensions of stem and blade modules in a sample of western North American Clovis points document clear allometric patterns, blades exhibiting more positive allometry than stems. Allometry was not an original design element of points but emerges as an integral character of their use-histories that requires control before attempting other inferences. 1. Introduction Archaeologists study chipped-stone artifacts called “points” for many good reasons. Among their properties, the size and shape of points are popular analytical subjects for what they reveal about age or cultural affnity, use and other cultural factors. This study concerns size and shape of late Pleistocene western North American Clovis points. For decades, archaeologists approached points as integral wholes, all aspects, dimensions and segments of their variation simultaneously contemplated. More recently they acknowledged the nontrivial impli- cations of the trivial fact that stone is a reductive medium. The size and shape of points at frst use may differ substantially from size and shape at discard, because they experience wear and damage in use that, if not irrevocable, is repaired by resharpening. This is one aspect of the reduction thesis; reduction patterns are characteristics of point types and specimens no less integral than their length or width (Ellis 2004; Iovita 2010:236; Lerner 2015:143; Presnyakova et al., 2018:162) and directly refect aspects of prehistoric behavior (D.S. Miller 2018:55–63). If all segments or modules of points experience proportional reduction, then points change in size but not in shape during their use-lives, i.e., isometrically. If reduction is disproportionate, modules experiencing varying kinds and degrees, then points change in shape as they change in size, i.e., allometrically. Pattern and degree of reduction experienced by points are worth study for several reasons (Shott 2020a, 2020b). Reduction in fake tools (Serwatka 2015:21) and technological bifaces that range from Paleo- lithic to late prehistoric (Hoffman 1985; Iovita 2011; Prentiss et al., 2017) generates variation in specimens of a single type suffcient to suggest more than one type among them if its effects are ignored, or to make specimens of different types look similar (Charlin and Cardillo 2018:123). Degree of reduction also is a measure of curation, an important theoretical quantity in lithic analysis (Binford 1973; Shott 1996). Distributions of reduction values among specimens ft theoretical models of tool use and wider adaptive practices. D.S. Miller (2018:55–63), for instance, used the marginal value theorem to model bifaces as resource patches, relating their degree of utility extracted, and therefore reduction, to varying hunting return rates. This treatment makes reduction a behavioral variable refecting long-term adaptive processes. Phylogenetic allometry among types linked by cultural transmission over long periods is yet another reason to study reduction variation in stone tools, new types perhaps emerging over time from allometric alteration of functional segments like stems (Charlin and Cardillo 2018). Finally, the reduction thesis and the allometric patterns that it generates relate to assemblage formation. Plotting the * Corresponding author. E-mail addresses: shott@uakron.edu (M.J. Shott), justinpatrickwilliams@gmail.com (J.P. Williams), Alan.Slade@austin.utexas.edu (A.M. Slade). Contents lists available at ScienceDirect Journal of Archaeological Science journal homepage: www.elsevier.com/locate/jas https://doi.org/10.1016/j.jas.2021.105359 Received 29 November 2020; Received in revised form 19 February 2021; Accepted 24 February 2021