Buccal dental microwear variability in extant African Hominoidea: taxonomy versus ecology

Abstract

Buccal microwear patterns on teeth are good indicators of the abrasiveness of foodstuffs and have been used to trace the dietary habits of fossil species, including primates and hominids. However, few studies have addressed the variability of this microwear. The abrasiveness of dietary components depends not only on the hardness of the particles ingested, but also on the presence of dust and other exogenous elements introduced during food processing. These elements are responsible for the microwear typology observed on the enamel surfaces of primate teeth. Here we analyzed the variability of buccal microwear patterns in African Great Apes (Gorilla gorilla and Pan troglodytes), using tooth molds obtained from the original specimens held in several osteological collections. Our results suggest that ecological adaptations at subspecies or population level account for differences in microwear patterns, which are attributed to habitat and ecological conditions within populations rather than differences between species. The findings from studies on the variability of buccal dental microwear in extant species will contribute to a better understanding of extinct hominids' diet and ecology.

Tooth Size Variation Related to Age in Amboseli Baboons

“…Among sifakas, King et al [2005] related tooth wear to individual fitness, in that older females, with more worn teeth, lost their infants at higher rates than younger females [King et al, 2005]. In addition, many studies have examined dental microwear in primates in relation to ecology [Ungar, 1990;Teaford, 1994;Godfrey et al, 2004;Nystrom et al, 2004;Ungar et al, 2004;El Zaatari et al, 2005;Galbany et al, 2005Galbany et al, , 2009.…”

Dental microwear texture analysis of late Pliocene Procynocephalus subhimalayanus (Primates: Cercopithecidae) of the Upper Siwaliks, India

“…The relationship between semi-terrestriality and consumption of foods with a high Young's modulus values is in part borne out by these analyses. The grit adhering to foods may be a fundamental source of dental microwear, both in the canopy [29] and with respect to habitat [25].…”

“…Whether grit is associated with a particular type of diet-such as the consumption of USOs-is possible, but the presence of a heavy grit signal is equally likely to be a reflection of habitat as it is of diet [25]. In xeric habitats, leaves, fruit and herbs can be covered by a thin layer of grit, particularly those proximate to ground level [42].…”

“…When fruit is scarce, fallback foods are consumed, including leaves and second choice fruits and herbs, bark, pith and insects (particularly among females). Herbs are close to ground level and may be covered with fracture resistant particles more often than arboreal leaves and fruits [25]. The two Gorilla that approximate Procynocephalus on the first canonical scores axis ( Figure 7) may exhibit extremes in textural complexity values (Asfc) from the consumption of abrasive grit on preferred herbs such as the shoots of Haumania danckelmaniana and the swamp herb Hydrocharis chavalieri both of which are eaten year round [43].…”

“…We anticipate that Procynocephalus will be more similar to larger-bodied taxa, such as grey-cheeked mangabey monkeys (Lophocebus) and perhaps Gorilla. Given the mineral accumulation on plants from grasslands and savannas [25], it may be the case that habitat heavily contributes to distinctions between primates living in tropical forests and those from temperate zones dominated by low lying shrubs, grasses and small trees. In this regard, Procynocephalus from the grasslands of the Upper Siwaliks may be distinct from extant forest primates from closed habitats, even those which are semi-terrestrial such as Gorilla.…”