Time wears on: Assessing how bone wears using 3D surface texture analysis

Abstract

Use-wear analysis provides a means of studying traces produced on animal bone during manufacture and use in an effort to reconstruct these processes. Often, these analyses are qualitative and based on experience and expertise. Previous studies have focused on interpreting final traces, but little is known about how these traces develop and change over time. We propose the use of an innovative quantitative method for studying bone surface traces that aims to reduce any unreliable or non-replicable results that can confound more traditional qualitative analyses. We seek to understand the basics of use-wear formation over Time by taking incremental molds of bone specimens subjected to a controlled, mechanical experiment. This study assesses how bone wears during extended use on three Material types (fresh skin, processed leather, or dry bark), from three initial Manufacturing states (unworked, ground with sandstone, or scraped with flint). With data obtained from a confocal disc-scanning microscope, we then apply 3D surface texture analysis using ISO 25178 parameters: surface roughness [Sa], autocorrelation length [Sal], peak curvature [Spc], and upper material ratio [Smr1]. We employ a multilevel multivariate Bayesian model to explain parameter variation under experimental conditions. Our findings show how duration of use strongly affects the transformation of the bone’s surface. Unworked bone is completely distinguishable from bone used for long time intervals and those modified by scraping. Interestingly, material wear does not often produce type-specific traces, but does affect the rate of bone alteration and how it is transformed. Specifically, fresh skin transforms bone at a faster rate than other materials. This novel quantitative and experimental approach enhances our understanding of the use of bone as a raw material for making and using tools and provides a foundation for future exploration of archaeological materials and questions.

Dust affects chewing efficiency and tooth wear in forest dwelling Western chimpanzees (Pan troglodytesverus)

“…Both fossil hominin examples show that more field observations and feeding experiments under controlled conditions are needed to better understand texture formation. To differentiate more clearly between extrinsic and intrinsic abrasive particles of varying sizes in the surface texture signature, we recommend developing new statistical models and using pattern recognition algorithms (such as those applied to bone wear analysis Martisius et al, ).…”

Rethinking Use-Wear Analysis and Experimentation as Applied to the Study of Past Hominin Tool Use

“…Initially based on 2D images (Grace et al 1985;Grace 1989), and later on 2D and 3D surface roughness measurements, this approach aims to create standardized criteria for variability within and between different types of wear traces. Such improvement was also made possible with the introduction of a wide range of imaging equipment and software, such as the tactile profilometer (Beyries et al 1988), atomic force microscopy (Faulks et al 2011;Kimball et al 1995), interferometry (d' Errico and Backwell 2009;Dumont 1982), laser profilometry (Stemp andStemp 2001, 2003), confocal microscopy (Evans and Donahue 2008;Evans 2014;Macdonald et al 2018;Stemp et al 2013;Stemp and Chung 2011), image analysis, and surface metrology software (Calandra et al 2019a, b, c;d'Errico and Backwell 2009;Ibáñez et al 2018;Martisius et al 2018;Sahle et al 2013). This variety of imaging equipment reflects the main aim of these approaches, which has focused on a quantitative identification and analysis of the different types of use-wear traces (e.g., polish and striations, see definitions below).…”

Connecting Middle Palaeolithic Datasets: the Interplay of Zooarchaeological and Lithic Data for Unravelling Neanderthal Behaviour

“…Results from these studies can be compounded further because many Middle Palaeolithic tools appear to have been used for multiple tasks (Monnier et al 2012). The development of more systematic, quantitative experimental approaches and methodologies (Rots et al 2016;Martisius et al 2018;Calandra et al 2019aCalandra et al , 2019b will help to provide new insights into the formation of such signatures within the archaeological record and their interpretive potential and drawbacks.…”