Neanderthal plant use and phytolith taphonomy in the Middle Paleolithic of Southwest France

The role of plants in Neanderthal subsistence is less well known than the role of animals due to differences in preservation and a subsequent lack of study. Phytoliths, the silica infillings of plant cells, are more durable than organic components of plants and can be used to reconstruct human activities, local plant ecology, and diagenetic alteration of archaeological sediments. This dissertation, comprising three articles, examines the relationship between Neanderthals and plants during the Middle Paleolithic (ca. 100,000-40,000 BP) of southwest France using phytolith analysis. The first article provides an analysis of the phytoliths recovered from the cave site of Roc de Marsal, relating phytolith concentrations and identifications to environmental change, natural deposition, and Neanderthal pyrotechnology. The analysis of 115 phytolith samples provides evidence for spatial patterning in plant remains related to hearth features and diachronic change in plant use coincident with a shift from warm stadial to cold glacial conditions. The second article applies morphometric statistics to a specific class of phytoliths, grass cells known as bilobates, to understand the range of variation within and among grass genera and to compare these results with an archaeological phytolith assemblage. More than 200 archaeological bilobates from Roc de Marsal are compared with those from seven modern reference specimens to assess these links. The analysis of the modern material indicates that some species are good candidates for morphometrics, but others should be avoided. The range of variation and lack of patterning in the archaeological assemblage suggest that Neanderthals at this site used multiple grass species. The third article presents the analysis of 102 phytolith samples from Pech de l’Azé IV in comparison to those from Roc de Marsal. The two sites are similar in terms of chronology, stratigraphy, artifacts, and preserved combustion features, but there are key differences in the structure/morphology of hearths and phytolith densities. The comparison of these two sites highlights variation in Neanderthal pyrotechnology and fuel use. The analysis also indicates that different phytolith recovery protocols are needed to maximize phytolith extraction due to differences in formation processes between sites and should be evaluated on a site by site basis.2019-11-27T00:00:00