Molar Macrowear Reveals Neanderthal Eco-Geographic Dietary Variation

Abstract

Neanderthal diets are reported to be based mainly on the consumption of large and medium sized herbivores, while the exploitation of other food types including plants has also been demonstrated. Though some studies conclude that early Homo sapiens were active hunters, the analyses of faunal assemblages, stone tool technologies and stable isotopic studies indicate that they exploited broader dietary resources than Neanderthals. Whereas previous studies assume taxon-specific dietary specializations, we suggest here that the diet of both Neanderthals and early Homo sapiens is determined by ecological conditions. We analyzed molar wear patterns using occlusal fingerprint analysis derived from optical 3D topometry. Molar macrowear accumulates during the lifespan of an individual and thus reflects diet over long periods. Neanderthal and early Homo sapiens maxillary molar macrowear indicates strong eco-geographic dietary variation independent of taxonomic affinities. Based on comparisons with modern hunter-gatherer populations with known diets, Neanderthals as well as early Homo sapiens show high dietary variability in Mediterranean evergreen habitats but a more restricted diet in upper latitude steppe/coniferous forest environments, suggesting a significant consumption of high protein meat resources.

Plant foods and the dietary ecology of Neanderthals and early modern humans

“…Studies of modern foragers document a cline in plant food consumption, with groups living in tropical latitudes consuming more plant foods than those in temperate or arctic latitudes (Kelly, 1995). Studies of Neanderthal dietary behavior have also suggested that ecogeographic factors influence dental microwear and mesowear (El Zaatari et al, 2011;Fiorenza et al, 2011). We predict that the geographic region from which samples came should also influence plant food consumption.…”

“…First, detailed analyses of both Neanderthal dental microwear (El Zaatari et al, 2011) and dental mesowear (Fiorenza et al, 2011) have suggested more variation within Neanderthal diets than previously expected. In both cases, Neanderthal groups living in southern and wooded environments had dental wear more similar to that of modern forager groups that consume a variety of foods, while Neanderthals in more northern and dry environments had diets similar to modern forager groups that consume predominantly meat.…”

“…There are many 2 The excavators of Klasies River suggest that the samples from Cave 1 Layer 14 and Shelter 1b layer 10 represent the same occupation of the site (Singer and Wymer, 1982). environments subsumed within both our European and African samples (as has been considered by El Zaatari et al, 2011;Fiorenza et al, 2011), and their effect on plant diet may be masked by lumping them together. Future studies including more sites and finer ecogeographic divisions may reveal these patterns.…”

An Experimental Approach to Evaluate the Correspondence Between Wear Facet Position and Occlusal Movements

“…In a wider perspective, it is believed that future experimental studies of occlusal movement, in combination with wear pattern analyses such as the OFA (Kullmer et al, 2009), will help to elucidate the correlation between food properties, occlusal movements, and tooth wear. The quantitative method applied here lends itself to analyses concerning the development of wear facets (Fiorenza et al, 2010(Fiorenza et al, , 2011a, the correlation between facet microstriations and macrowear dip directions, and to the interpretation of differences, variability, and creation of tooth wear patterns. As the macrowear pattern reflects a long chronologic record of occlusal movements and behavior, it is here emphasized the potential of such studies for the reconstruction of dietary variability, mastication behavior, and evolutionary adaptation in fossil (e.g., paleontologic and paleoanthropologic) and modern species.…”

“…A stereotypic motion of the lower jaw was described as a general feature of the primate masticatory cycle Kay, 1972, 1973;Kay and Hiiemae, 1974;Kay, 1977;Maier, 1977Maier, , 1978Maier, , 1984, from which a maximum of 13 complementary facet pairs develop on the molar occlusal surface (Maier and Schneck, 1981). Accordingly, even though several factors (i.e., food properties, environmental, and behavioral factors) influence the shape, size, and gross rate of facet wear (Janis, 1990;Lussi, 2008;Fiorenza et al, 2011a), their topographic position on the occlusal surface mainly depends on crown morphology, the relationship of antagonistic cusps and basins, and jaw movements (Fiorenza et al, 2010(Fiorenza et al, , 2011b. Based on this, Kullmer et al (2009) proposed that a detailed analysis of a wear facets spatial position (occlusal fingerprint analysis, OFA) could precisely predict individual occlusal jaw movements.…”