A reassessment of human cranial indices through the Holocene and their implications for the peopling of South America Susan C. Kuzminsky a,b, ⁎, Nina Coonerty b , Lars Fehren-Schmitz b a Instituto de Investigaciones Arqueológicas y Museo R.P Gustavo Le Paige, Universidad Católica del Norte, 380 Calle Le Paige, San Pedro de Atacama, Chile b Anthropology Department, University of California, 1156 High Street, Santa Cruz, CA 95064, USA abstract article info Article history: Received 17 September 2016 Received in revised form 15 December 2016 Accepted 28 December 2016 Available online 19 January 2017 South American populations have played a critical role in elucidating the timing, origin, and migration routes of the first Americans. Among the ongoing debates surrounding the peopling of South America, there has been a great deal of focus on the cranial shape of prehistoric populations on this continent, which some researchers have described as having two distinct forms. The cranial shape of early Holocene Paleoamericans, which predate approximately 8000 years BP, has been categorized as dolichocephalic (long-headed), while late Holocene pop- ulations have been generally described as brachycephalic (round-headed), despite more recent assessments that examine variation with a higher level of precision. Although more detailed analytical approaches to investigating craniofacial variation are available, researchers still categorize South American crania as having these two head shapes. These distinctions in head shape have been used to infer multiple origin models, some of which contend that the dolichocephalic population was biologically distinct and later replaced by brachycephalic individuals. In contrast, genetic studies infer a common ancestral origin among all prehistoric South American populations. Given discrepancies between genetic and cranial data, our study tests the hypothesis that Holocene populations consist of two cranial morphologies that coincide with the early and late Holocene periods. Using high-resolution 3D models generated from a laser surface scanner, cranial indices for 95 individuals from western South America dating from the Early, Middle, and Late periods were analyzed, most of which have been excluded from cranial assessments in South America. Our results show that the majority of crania analyzed in this study have an inter- mediate (mesocephalic) head shape, spatiotemporal variability, and no clear transition from dolichocephaly to brachycephaly during the Holocene. By re-examining the relevance of these categories that are determined through the calculation of the cranial index, and general morphological descriptions (long and narrow or short and wide skulls) that coincide with them, our research offers valuable insight into the ongoing debates centered on the colonization of South America. Given our results, we propose that caution should be used when referring to the terms “dolichocephalic” and “brachycephalic” head shapes and the general morphological descriptions for these terms to categorize early and late Holocene South American populations. © 2016 Elsevier Ltd. All rights reserved. Keywords: Human skeletal biology Bioarchaeology Cranial variation 3D laser scanning Andean archaeology 1. Introduction Few topics in anthropology have garnered as much attention as the peopling of the Americas. Recent investigations have confirmed the Asian origins of the First Americans (e.g., Rasmussen et al., 2014 and 2015; Schurr, 2015), refined radiocarbon dating techniques and chro- nology (e.g., Fehren-Schmitz et al., 2015; Rademaker et al., 2013; Waters and Stafford, 2007), and produced new insights into early human-environment interactions on both continents (e.g., Dillehay et al., 2008, 2015; Eggers et al., 2011; Halffman et al., 2015; Rademaker et al., 2014). Such advancements have revealed that the adaptive and evolutionary processes of these early colonizers were much more varied than initially thought, particularly with respect to tool use, diet, and so- cial complexity (e.g., Dillehay et al., 2008, 2015; Eggers et al., 2011; Erlandson et al., 2015l; Halffman et al., 2015; Strauss et al., 2015b). De- spite these advancements, the timing of entry and dispersal routes of the first Americans continue to generate considerable debate among scholars (e.g., de Azevedo et al., 2011; Chatters et al., 2014; Eren et al., 2013; Halligan et al., 2016; Heintzman et al., 2016; Hubbe et al., 2015a; Jackson et al., 2014; Stanford and Bradley, 2012; see also Borrero, 2016). Archaeological and genetic data from both hemispheres indicate that people first dispersed from Asia into the Americas some- time between 20,000 and 14,000 years BP, although agreements on these dates and the number of migrations are far from unanimous Journal of Archaeological Science: Reports 11 (2017) 709–716 ⁎ Corresponding author at: Instituto de Investigaciones Arqueológicas y Museo R.P Gustavo Le Paige, Universidad Católica del Norte, 380 Calle Le Paige, San Pedro de Atacama, Chile. E-mail addresses: skuzminsky@ucn.cl, skuzmins@ucsc.edu (S.C. Kuzminsky), ninarcoonerty@gmail.com (N. Coonerty), lfehrens@ucsc.edu (L. Fehren-Schmitz). http://dx.doi.org/10.1016/j.jasrep.2016.12.039 2352-409X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep