Dental microwear texture gradients in guinea pigs reveal that material properties of the diet affect chewing behaviour

ABSTRACT Dental microwear texture analysis (DMTA) is widely used for diet inferences in extant and extinct vertebrates. Often, a reference tooth position analysed specimens, while isolated teeth are lumped together fossil datasets. It therefore important to test whether dental (DMT) specific and, if so, what causes the differences wear. Here, we present results from controlled feeding experiments with 72 guinea pigs, which received either fresh or dried natural plant diets of different phytolith content (lucerne, grass, bamboo) pelleted without mineral abrasives (frequently encountered by herbivorous mammals habitats). We tested gradients along upper cheek row. Regardless abrasive content, pigs on displayed an increase surface roughness row, indicating that posterior positions experience more wear compared anterior teeth. Guinea feedings plants low abrasiveness (fresh dry lucerne, grass) showed almost no DMT between positions, individuals (dry gradient decreasing suggest involves continuous intake comminution grinding, resulting mainly processing food already partly comminuted moistened. Pelleted require crushing, exerts higher loads, especially where bite forces highest. These chewing behaviour result opposing versus diets.