Identifying Weapon Delivery Systems Using Macrofracture Analysis and Fracture Propagation Velocity: A Controlled Experiment

Abstract

In the last few decades, zooarchaeological studies have demonstrated beyond doubt that the hunting abilities of hominins were quite formidable from quite early on. Unfortunately, direct evidence for the use of weapons in hunting is quite rare and depends heavily on the preservation of organic elements. In particular, in the absence of such evidence, it is notoriously difficult to pinpoint the first appearance of complex, mechanically-assisted projectiles (such as darts and arrows) in the archaeological record. In this chapter, we present data from a controlled ballistic experiment with the aim of establishing patterns in the formation of impact fractures that would allow for the discrimination of thrusting spears, (hand-thrown) javelins, and spearthrower darts and arrows. By controlling for the weapon tip shape, weight, and raw material, impact angle (IA), as well as target composition, we are able to focus on the key elements that separate the different launching systems: velocity and kinetic energy output. The results show that fracture scar length is proportional to kinetic energy at impact, but only if the impact is perpendicular, as acute IAs reduce the energy requirements for the production of large, typical impact fractures. We also confirm previous results of Hutchings (JAS 38:1737-1746, 2011) regarding the relationship between precursory loading rate and fracture propagation speed, documenting a weak linear relationship between the two in our sample. We conclude by discussing the implications of this study for identifying different weapon armatures in the archaeological record.

Ballistic Study Tackles Kinetic Energy Values of Palaeolithic Weaponry

“…Several authors have tried to isolate the influence of specific parameters on the fracturing process of stone points; in particular, the KE (Iovita et al . , ; Sano and Oba ; Clarkson ) and the angle of contact (Iovita et al . , ).…”

“…, ; Sano and Oba ; Clarkson ) and the angle of contact (Iovita et al . , ). In most cases, the experimental set‐up opted for (e.g., an airgun or crossbow) has permitted the use of predefined values for the KE of the projectile and a certain degree of reproducibility.…”

“…Such reflections rely heavily on a model of linear evolution of the invention of different propulsion modes, starting from ‘simple’ non‐assisted projection techniques such as spear thrusting and throwing and advancing towards more ‘complex’ assisted hunting with spear‐throwers or bows (Shea and Sisk ; Iovita et al . ). This model is largely based on a few important discoveries of organic remains in Europe, namely the Lower and Middle Palaeolithic wooden spears or spear fragments from Schöningen (Thieme ), Clacton‐on‐Sea (Oakley et al .…”

“…Over the past decade, the focus in debates on hunting technology has shifted from projectile identification to the detection of different propulsion modes in the Palaeolithic (Geneste and Plisson ; Cattelain ; Shea ; Iovita et al . , ; Sano and Oba , ; Clarkson ; Pargeter et al . ).…”

Were tanged points mechanically delivered armatures? Functional and morphometric analyses of tanged points from an Upper Paleolithic site at Jingeuneul, Korea

“…Recently, controlled projectile experiments have been performed to confirm a correlation between projectile systems and their impact trace patterns. Even though one of the authors (K. Sano) has already conducted such projectile experiments with backed points (Sano and Oba 2015) and trapezoids ) and there have been projectile experiments with Levallois (Iovita et al 2016) and Mousterian points (Clarkson 2016), the fracture patterns are dependent not only on the impact velocities but also on the stone tip morphology (Sano and Oba 2014). Identifying the precise delivery mode of the Jingeuneul tanged points requires controlled projectile experiments with Korean tanged points.…”