Quaternary International xxx (xxxx) xxx Please cite this article as: Erik J. Marsh et al., Quaternary International, https://doi.org/10.1016/j.quaint.2023.10.004 1040-6182/© 2023 Elsevier Ltd and INQUA. All rights reserved. Spearthrower or bow? Hafted projectile points from the Americas refne comparative baselines for tracking projectile technologies Erik J. Marsh * , Lucía Yebra , Silvina Celeste Castro , Valeria Cortegoso Consejo Nacional de Investigaciones Científcas y T´ ecnicas (CONICET), Laboratorio de Paleoecología Humana, Instituto Interdisciplinario de Ciencias B´ asicas, Padre Jorge Contreras 1300, Parque General San Martín, 5500, Mendoza, Argentina A R T I C L E INFO Keywords: Projectile points Spearthrowers Bows Darts Arrows Americas ABSTRACT The invention or adoption of bows is one of the most signifcant global shifts in humanity’s history, and tracking this in the archaeological record depends on metrically distinguishing dart and arrow projectile points. Given the importance of comparative databases in this endeavor, this paper presents an expanded compilation of mea- surements on 85 hafted points from North America. For South America, we present unpublished data for 22 hafted points and 61 foreshafts. A clear metric gap in point width at 14–15 mm separates arrows and darts. This refects the weapons’ different physical requirements, since these points come from historically independent regions and periods. These patterns are not replicated in ethnographic arrows, which are consistently larger than archaeological arrows. We suggest they not be used in archaeological comparisons. Hafted darts are notably larger than unhafted darts from archaeological sites, which is mostly due to use-life reductions. We suggest that there is no universally applicable data set, nor derived formula or index, that can be used to identify archaeo- logical points as darts or arrows. We recommend nonparametric comparisons focusing on natural breaks in cross- cultural archaeological data. 1. Introduction A key issue in global archaeology is development of projectile weapon systems. Wielding these weapons is a distinguishing feature of Homo sapiens that has underwritten our adaptive success in ecosystems around the world (Churchill, 1993; Coolidge et al., 2016; Hoffecker and Hoffecker, 2017; Hughes, 1998; Lombard, 2016, 2022; Young, 2009). For millennia, the dominant projectile weapon system was the spear- thrower, which was later replaced by the bow and arrow. Hence a key question for archaeologists around the world is when this transition happened in each region and whether it was the result of independent, convergent invention or cultural transmission. In many regions, the earliest archers helped drive a suite of cultural, economic, and social changes (Bingham et al., 2013; see other articles in the same issue). For this reason, archaeologists seek to reliably identify weapons in the archaeological record, which are most frequently documented by one the most important and abundant tools in humanity’s history: lithic projectile points. Very large points were probably used as throwing or thrusting spears or knives, medium-sized points were hafted onto dart foreshafts to be shot from spearthrowers and still smaller points were hafted onto arrows shot from bows (Baker and Kidder, 1937). This size-based inference is the basis for “most of what we believe about the spread of bows and arrows through the Americas” (Thomas, 2000, p. 48) and even Homo sapiens’ frst use of projectiles (Sisk and Shea, 2011). However, clear quantitative distinctions have not been identifed, since measurements for darts and arrows usually overlap (see Davies, 2014; Marsh et al., 2023). This paper seeks to refne the comparative baselines we use to make metric distinctions. Projectile point studies rely almost exclusively on Thomas’ (1978) ethnographic arrow dataset, because it is large, well-documented, and there are few better alternatives (e.g., Bradbury, 1997). For darts, Shott (1997) expanded on Thomas’ (1978) sample and used robust discriminant methods to offer researchers an attractively simple formula to identify a point as a dart or arrow. This formula has been widely applied in the Americas and other global regions (e.g., chapters in Belardi et al., 2021; articles in Bingham et al., 2013; Sisk and Shea, 2011). However, there are issues with the underlying comparative collection that make some question its utility (Hildebrandt and King, 2012, p. 795; Reed and Geib, 2013, p. 105). Unlike the Old World, there was only a single type of bow present in nearly all of the prehispanic New World, the simple or self bow (Marsh et al., 2023). Nearly all New World fetchers made composite shafts: a * Corresponding author. E-mail address: emarsh@mendoza-conicet.gob.ar (E.J. Marsh). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint https://doi.org/10.1016/j.quaint.2023.10.004 Received 8 July 2023; Received in revised form 12 October 2023; Accepted 17 October 2023