Paleoindian Unifacial Stone Tool ‘Spurs’: Intended Accessories or Incidental Accidents?

Abstract

Paleoindian unifacial stone tools frequently exhibit distinct, sharp projections, known as “spurs”. During the last two decades, a theoretically and empirically informed interpretation–based on individual artifact analysis, use-wear, tool-production techniques, and studies of resharpening–suggested that spurs were sometimes created intentionally via retouch, and other times created incidentally via resharpening or knapping accidents. However, more recently Weedman strongly criticized the inference that Paleoindian spurs were ever intentionally produced or served a functional purpose, and asserted that ethnographic research “demonstrates that the presence of so called ‘graver’ spurs does not have a functional significance.” While ethnographic data cannot serve as a direct test of the archaeological record, we used Weedman’s ethnographic observations to create two quantitative predictions of the Paleoindian archaeological record in order to directly examine the hypothesis that Paleoindian spurs were predominantly accidents occurring incidentally via resharpening and reshaping. The first prediction is that the frequency of spurs should increase as tool reduction proceeds. The second prediction is that the frequency of spurs should increase as tool breakage increases. An examination of 563 unbroken tools and 629 tool fragments from the Clovis archaeological record of the North American Lower Great Lakes region showed that neither prediction was consistent with the notion that spurs were predominately accidents. Instead, our results support the prevailing viewpoint that spurs were sometimes created intentionally via retouch, and other times, created incidentally via resharpening or knapping accidents. Behaviorally, this result is consistent with the notion that unifacial stone tools were multifunctional implements that enhanced the mobile lifestyle of Pleistocene hunter-gatherers.

The evolution and stability of stone tools: The effects of different mobility scenarios in tool reduction and shape features

“…The shapes of prehistoric tools have been understood as a reflection of many different concepts, depending on the theoretical framework in which a particular lithic study was conducted. From classificatory approaches to dynamic interpretations, changes in the morphological features of tools have been linked to cognitive capabilities (Holloway, 1969;Gowlett, 2006), style (Lenoir, 1975;Tiffagom, 2003), cultural transmission (Lycett, 2008;Buchanan and Collard, 2010;Schillinger et al, 2014), mobility dynamics (Shott, 1986;Blades, 2003;Sellet, 2013), site function (Bachelleire et al, 2011), reduction (Dibble, 1984(Dibble, , 1987bMcPherron, 1995;Shott and Ballenger, 2007;Brumm and McLaren, 2011;Eren et al, 2013) and many other aspects of the behaviors of prehistoric peoples.…”

“…In contrast, reduction approaches have focused (primarily but not exclusively) on unifacially retouched stone tools, primarily scrapers sensu lato (e.g. Dibble, 1987a;Kuhn, 1990;Shott, 1995;Shott, 1996;Attenbrow, 2002, 2003;Eren et al, 2005;Shott and Weedman, 2007;Eren et al, 2013;Morales et al, 2015). This work attempts to link shape and reduction analyses in order to test for relationships between the shape of a tool and its reduction stage.…”

Environment-induced changes in selective constraints on social learning during the peopling of the Americas

“…“Pointed” was defined using Eren et al .’s47 “spur procedure.” A tang (basal ear) was determined to be “pointed” if it extended through a box 3 mm by 1 mm (Fig. 5).…”

“…This character was assessed by determining whether the tangs (basal ears) of a point were pointed or not. “Pointed” was defined using Eren et al .’s 47 “spur procedure.” A tang (basal ear) was determined to be “pointed” if it extended through a box 3 mm by 1 mm ( Fig. 5 ).…”

Clovis Colonization of Eastern North America: A Phylogenetic Approach

“…Character states in character V (outer tang angle) were determined as follows: if both tangs are greater than 92 degrees the character is "diverging"; if both tangs are less than 88 degrees the character is "converging"; if both tangs are between 88 and 92 degrees the character is "straight"; if the tangs differ in the above categories the character is "multistate." Character VI (tang tip shape) was measured by treating the tangs as "spurs" and determining the pointy or blunt status following the procedure of Eren, Jennings, and Smallwood (2013).…”