We studied the temporal and spatial variation of diet and oral health of human populations that inhabited the central region of Argentina during the Late Holocene (4000–300 BP) by evaluating isotopic data (δ13Ccol, δ15N), physiological stress indicators (tooth wear), and infectious dental diseases (caries). The sample of 49 individuals was recovered from archaeological sites located in the province of Córdoba, dated by AMS on collagen to a range of 4058 ± 89 years BP to 370 ± 15 14C years BP. After calculating the prevalence of caries and the average dental wear, we compared these values based on regional origin (central highlands and eastern lowlands), temporal assignation (early Late Holocene, late Late Holocene), and sex (female and male). We found clear regional and temporal differentiation, which we interpret as resulting from differential use of plant resources among the regions and a slight deterioration in oral health in the Late Holocene. Stable isotope analysis indicates food consumption of C3 and C4 resources, although the observed temporal variations in the isotopic values may indicate an introduction of C4 resources in the later Late Holocene, mainly in the mountainous region.

The dietary regime of Equus capensis from the Middle Pleistocene of South Africa is investigated by mesowear analysis. Results indicate that the mesowear signature of this species resembles that of two extant mixed feeders, the Grant's Gazelle (Gazella granti) and the Thomson's Gazelle (Gazella thomsoni), suggesting a mixed feeding dietary strategy for E. capensis. The mesowear signature of a contemporaneous population of Equus mosbachensis from Europe (Arago, France) is also determined for comparative purposes and has a typical grazing signature. In general, all extant species of Equus are believed to be almost exclusively grazers. However, a considerable degree of dietary flexibility is recently reported. The dietary signal of E. capensis is considered to be the result of feeding on the unique fynbos vegetation, which was beginning to establish itself at this time in southwestern South Africa. Grasses are a minor component of this floral kingdom. Our findings thus provide further evidence for the unexpected flexibility in feeding strategies of Equus, the most widely distributed equid taxon in the Quaternary. They highlight the potential use of the attrition"abrasion wear equilibrium as a habitat indicator, by mirroring the availability of food items in mammalian herbivore ecosystems.

The free-ranging feeding behaviours of five adult koalas Phascolarctos cinereus with varying degrees of tooth wear were investigated using acoustically sensitive radio telemetry. An increase in tooth wear was found to be associated with a significant increase in the average amount of time spent feeding, average number of leaves consumed and the average number of daily chews. This suggests that koalas compensate for tooth wear by increasing food intake. Furthermore, there was a significant increase in the average number of chews per leaf and average chew rate, suggesting a greater investment in processing each leaf.

Naked mole-rats Heterocephalus glaber are highly social hystricomorph rodents endemic to the arid regions of East Africa. Living entirely underground, they excavate an extensive system of tunnels with their continuously growing extra-buccal incisors. The majority of the burrow is composed of foraging tunnels, constructed in search of the underground roots and tubers that form their staple diet. Subterranean foraging imposes risks associated with not finding food, and a high energetic cost, and in addition could be limited by the rate of wear of the incisor teeth. The aim of this study was to determine eruption rates for mandibular incisors in naked mole-rats to investigate whether they showed evidence of faster eruption as an adaptation to their subterranean niche and mode of digging. Impeded eruption rates (when the teeth were left in normal occlusion) were initially determined over a period of 1 week in a group of 12 naked mole-rats kept in laboratory conditions. Unimpeded eruption rates were then monitored in the same animals by cutting one mandibular incisor free of occlusion thrice weekly, and measuring growth over a 2-week period. Mean daily impeded eruption rates were c. 228.7±17.5 μm, while mean daily unimpeded rates were higher at c. 624.7±10.4 μm. While impeded eruption rates under laboratory conditions may be an underestimate of the rates occurring in the wild, unimpeded rates (usually about twice the impeded rate) indicate the maximum potential eruption rates of the teeth and are independent of functional activity. These data are not dissimilar from those determined for laboratory rodents and lagomorphs suggesting that the naked mole-rat does not display unusual patterns of eruptive behaviour. Tooth wear resulting from their subterranean lifestyle may be offset as a limiting factor by the social behaviour of the naked mole-rat, where digging activity is distributed among a large workforce during favourable burrowing conditions.