Digital cementum luminance analysis (DCLA): a tool for the analysis of climatic and seasonal signals in dental cementum

Abstract

Cementum banding patterns have been used by archaeozoologists and wildlife managers for a number of decades to assess the season and age at death of mammalian populations. However, the observation and measurement of the nature of cementum banding, especially that of the final band, has proved to be difficult except under conditions of excellent preservation and advanced microscopy. The research presented here details a method for extracting luminance data from the banding patterns of cementum in order to quantify the optical properties of cementum tissue. By doing so, analysis of the relationship between cementum deposition and environmental variables is achieved. We present the results of a digital cementum luminance analysis (DCLA) on a sample of first molars from two species, Ovis aries, Soay and Capra ibex. The results indicate that significant relationships occur between seasonal temperature changes and cementum histology. Furthermore, we show that luminance values can be used to assess the geographical range of genetically similar populations. Our results demonstrate that the study of luminance is a vital tool for the quantitative study of dental cementum for both archaeological and ecological studies.

Age at death estimation by cementochronology: Too precise to be true or too precise to be accurate?

“…The negative coefficient establishes that the older subject is the lower the readability. This statement reflects some observations in large mammals where older/inner annuli appear thinner and compressed in Ovis aries and Capra ibex (Wall‐Scheffler & Foley, ). Comparable descriptions are made on immature Ursus maritimus where cementum waving pattern becomes compacted in older individuals (Hensel & Sorensen, ).…”

Digital Cementum Luminance Analysis and the Haua Fteah Hominins: How Seasonality and Season of Use Changed Through Time*

“…Luminance graphs and numerical values for each HL and LL band were then collected using the MATLAB program, following the protocol laid out in Wall and Wall (2006) and Wall‐Scheffler and Foley (in press).…”

“…In addition, seasonality studies utilizing dental cement are enhanced by the quantitative evaluation of luminance profiles (Wall‐Scheffler and Foley in press). The study of luminance allows the researcher to assess not simply the season of and age at death of faunal remains, but also to interpret seasonal changes over time.…”

“…The study of luminance allows the researcher to assess not simply the season of and age at death of faunal remains, but also to interpret seasonal changes over time. Differences between the intensity of low‐luminance (LL) and high‐luminance (HL) bands have been shown to increase in conjunction with increasing differences between known summer and winter temperatures (Wall‐Scheffler and Foley in press). The highly significant predictive relationships between luminance and temperature among modern ungulates can now be tested at a site that covers a wide temporal period and that has a considerable number of samples.…”

Hunting behavior and Neanderthal adaptability in the Late Pleistocene site of Pech-de-l'Azé I

“…However several factors have been identified as influencing the deposition pattern. For instance climatic variation (Wall-Scheffler and Foley, 2008), demographic stress (McCullough, 1996) or food procurement (Lieberman, 1993) may influence the rhythm of deposition and some variability may be seen within a population (Rolandsen et al, 2008). Besides, some species have been described as only partially following the predictable pattern (Lubinski and O'Brien, 2001;Lam, 2008).…”