XX. Measuring up to Environmental Archaeology: New Biometric Applications to the Study of Past Plant and Animal Remains

The reconstruction of past fire regimes through physical and chemical analysis is critical to understanding human-ecological dynamics and their influence on past and present landscapes. Quantification of macroscopic charcoal accumulation in sedimentary archives provides reliable information on fire frequency and the vegetation types burned. Established methods for charcoal quantification utilize chemical preparation methods that are destructive to non-charred macrobotanical remains. Using macrobotanical remains in cores from the inner Congo Basin, we apply image analysis of samples under refracted and transmitted light to quantify charcoal accumulation and characterize local vegetation at the coring site. After classification of the plant remains based on color, size, and morphological characteristics, we compare our results with standard microcharcoal analysis using bleached samples. Our preliminary findings provide first insights into fire dynamics in Congo Basin swamp forests and provide a roadmap for developing non-destructive methods of analyzing macrobotanical remains and assessing microcharcoal accumulation rates.

Barbara Lawrence published morphological criteria for identifying pronghorn (Antilocapra americana) and mule deer (Odocoileus hemionus) from skeletal remains in the U.S. Southwest, and these criteria are routinely used in the analysis of archaeofaunas across North America. Some criteria are often extrapolated to other related species, such as white-tailed deer (Odocoileus virginianus). Despite the widespread and general use of Lawrence’s protocols, zooarchaeologists have not assessed whether these criteria discriminate taxa when larger sample sizes are considered or when the same taxa are evaluated from different geographic areas. Researchers have also not demonstrated that observers can identify these criteria. Here, we developed linear measurements to capture morphological criteria for identifying pronghorn and mule deer from the astragalus. We investigate intra- and interobserver variability in measurement error and determine the probability of successful taxonomic identification using the criteria. Our results offer a means to assess and thereby bolster data quality in faunal analysis.

Reconstructing the environment is critical for understanding past human-environment relationships. The common use of species presence-absence and relative abundance works well across large spatial and temporal resolutions and with species with unique environmental requirements. However, this is not necessarily the case. Periods and areas where species have remained static over long periods preclude using these methods.

Using paleodietary proxies can aid in this conundrum. Mechanical properties of food leave distinct wear patterns (tribology) on the teeth of herbivores and can be used as paleoecological proxies. For example, fossils with signs of dental wear indicative of grazing can be interpreted as the presence of grasslands. At the same time, evidence for browsing can be used to suggest more closed and wooded habitats. New imaging methodologies, e.g., white-light confocal microscopy and scale-sensitive fractal analysis, allow for more robust conclusions. This paper will discuss the use and misuse of dental tribology in archaeology.

White-tailed deer and mule deer occur over much of North America, with significant overlap in the western United States including Arizona. Though white-tailed and mule deer occupy different environmental zones, and can differ in size, they have similar skeletal morphology. When archaeologists have attempted to differentiate white-tailed deer and mule deer skeletal elements, they generally rely upon size as the distinguishing factor. In 2004 Jodi A. Jacobson developed a system for differentiating these species using post-cranial skeletal landmarks. We tested the reliability of individual landmarks in Jacobson’s system by having volunteers perform a blind study using 34 modern reference samples from two collections curated by the Arizona State Museum. This analysis also enables us to test the consistency with which analysts with varying levels of experience could apply Jacobson’s system.