Jennifer Leichliter

Dental microwear of sympatric rodent species sampled across habitats in southern Africa: Implications for environmental influence.

Dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil vertebrates. Nevertheless, some studies have recently questioned the efficacy of this approach, suggesting that aspects of habitat unrelated to food preference, especially environmental grit load, might have a confounding effect on microwear patterning that obscures the diet signal. Here we evaluate this hypothesis by examining microwear textures of 3 extant sympatric rodent species that vary in diet breadth and are found in a variety of habitat types: Mastomys coucha, Micaelamys namaquensis and Rhabdomys pumilio. We sample each of these species from 3 distinct environmental settings in southern Africa that differ in rainfall and vegetative cover: Nama-Karoo shrublands (semi-desert) and Dry Highveld grasslands in the Free State Province of South Africa, and Afromontane (wet) grasslands in the highlands of Lesotho. While differences between habitat types are evident for some of the species, inconsistency in the pattern suggests that the microwear signal is driven by variation in foods eaten rather than grit-level per se. It is clear that, at least for species and habitats sampled in the current study, environmental grit load does not swamp diet-related microwear signatures.

Grass leaves as potential hominin dietary resources

Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C4 component in the diets of most taxa, and grass leaves are the single most abundant C4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of grass leaves with the plants growing alongside them in African savanna habitats. We also compare grass leaves to the leaves consumed by other hominoids and demonstrate that many, though by no means all, compare favorably with the nutritional and mechanical properties of known primate foods. Our data reveal that grass leaves exhibit tremendous variation and suggest that future reconstructions of hominin dietary ecology take a more nuanced approach when considering grass leaves as a potential hominin dietary resource.

Exploring C-4 plant foods: The nutritional properties of South African savanna vegetation

Leprosy is one of the few specific infectious diseases that can be studied in bioarchaeology due to its characteristic debilitating and disfiguring skeletal changes. Leprosy has been, and continues to be, one of the most socially stigmatising diseases in history, over-riding all other aspects of social identity for the sufferers and frequently resulting in social exclusion. This study examines the stable isotopic evidence of mobility patterns of children, adolescents, and young adult individuals with the lepromatous form of leprosy in Medieval England (10 th –12 th centuries AD) to assess whether the individuals buried with the disease were non-locals, possibly from further afield. Enamel samples from 19 individuals from the St. Mary Magdalen Leprosy Hospital, Winchester (UK) were selected for strontium ( 87 Sr/ 86 6U DQG R[\JHQ į 18 O) stable isotope analysis based on age at death (<30 years), the presence of bone changes associated with lepromatous leprosy, and the underlying geology of their burial locations. The results from these data indicate that the St. Mary Magdalen Leprosy Hospital received an almost equal mixture of local and non-local individuals from further afield, including early pilgrims. At present, the St. Mary Magdalen Leprosy Hospital is the earliest dedicated leprosaria found within Britain and mobility studies such as these can help elucidate and test some of the broader historical notions and identities associated with the movements of those infected with the disease in Medieval England.