Controlled feeding trials with ungulates: a new application of in vivo dental molding to assess the abrasive factors of microwear

摘要: Microwear, the quantification of microscopic scratches and pits on occlusal surfaces tooth enamel, is commonly used as a paleodietary proxy. For ungulates (hoofed mammals), scratch-dominant microwear distinguishes modern grazers from browsers, presumably result abrasion grass phytoliths (biogenic silica). However, it also likely that exogenous grit (i.e. soil, dust) contributing factor to these patterns, which may reflect soil ingestion varies with feeding height and/or environmental conditions (e.g. dust production in open arid habitats). This study assessed contribution wear by measuring effects fine- medium-grained silica sand enamel using novel live-animal tooth-molding technique. It therefore constitutes first controlled experiment vivo abrasives different sizes. Four sheep were fed three diet treatments: (1) mixture Garrison Brome hay (control), (2) treated fine-grained (180–250 µm) (3) (250–425 µm). We found significant increase pit features was correlated an grain size grit, corroborating earlier chewing simulation experiments produced through grit-induced ‘grit effect’). Our results support interpretation large grains fracturing create smaller, more abundant angular particles capable abrasion, jaw movement defining feature shape scratch or pit).