Date of Graduation

5-2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Anthropology (PhD)

Degree Level

Graduate

Department

Anthropology

Advisor/Mentor

Peter S. Ungar

Committee Member

Jerome C. Rose

Second Committee Member

Thomas J. Green

Third Committee Member

Jean-Jacques Hublin

Keywords

Anatomically modern humans, Anterior teeth, Dental microwear, Dietary strategies, Modern humans, Neandertals

Abstract

The extreme gross wear of Neandertal anterior teeth has been a topic of debate for decades. Several ideas have been proposed, including the excessive mastication of grit-laden foods and non-dietary anterior tooth use, or using the anterior dentition as a clamp or tool. This second idea has been the most examined, and was taken from analogy of Arctic populations who used their anterior dentition in this manner. However, combining wear variables and examining them in relation to important factors, such as climate, location, and time, has been challenging to incorporate into interpretive models. The present study seeks to better understand Neandertal anterior tooth wear by integrating these factors with the three wear variables known to affect anterior dental microwear signatures: diet, abrasive load, and non-dietary anterior tooth use. High-resolution casts of 65 Neandertal individuals from 30 sites and 42 anatomically modern humans from 16 sites were scanned for anterior dental microwear textures using a white-light confocal profiler. Using a 100x objective lens, four adjacent scans were generated measuring a total area of 204 x 276 µm. These scans were analyzed using Toothfrax and SFrax software packages. The fossil hominin samples were then compared to several modern human comparative samples. The Neandertal sample showed significant variation by climate, location, and OIS. The anisotropy and textural fill volume values of the cold-open-steppe Neandertals were significantly lower and higher, respectively, and both attributes were more constricted than those of the warm-woodland Neandertals. This pattern suggests the cold-open-steppe Neandertals may have been using their anterior dentition frequently in clamping and grasping activities. Variation in heterogeneity and complexity by location and OIS time interval may suggest differences in abrasive loads. The anatomically modern human sample showed significant variation in heterogeneity 3x3 and 9x9 distribution variance by climate, location, and time, suggesting differences in abrasive loads in each factor. No differences were found in central tendencies for this sample, and the overall signal suggests little non-dietary anterior tooth use was employed. The differences in non-dietary anterior tooth use signals between the two fossil hominins are suggested to be due to differences in tool technology.

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