0000000000661027

AUTHOR

Louise F. Martin

Dental wear proxy correlation in a long-term feeding experiment on sheep ( Ovis aries )

Dietary reconstruction in vertebrates often relies on dental wear-based proxies. Although these proxies are widely applied, the contributions of physical and mechanical processes leading to meso- and microwear are still unclear. We tested their correlation using sheep ( Ovis aries , n = 39) fed diets of varying abrasiveness for 17 months as a model. Volumetric crown tissue loss, mesowear change and dental microwear texture analysis (DMTA) were all applied to the same teeth. We hereby correlate: (i) 46 DMTA parameters with each other, for the maxillary molars (M1, M2, M3), and the second mandibular molar (m2); (ii) 10 mesowear variables to each other and to DMTA for M1, M2, M3 and m2; and (…

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The turnover of dental microwear texture: Testing the" last supper" effect in small mammals in a controlled feeding experiment

Dental microwear texture (DMT) analysis is commonly applied for dietary reconstruction of vertebrates. The temporal scale on which dietarily informative microscopic wear forms on enamel surfaces is crucial to infer dietary flexibility and seasonality. Microwear is assumed to form shortly before the individual's death, reflecting information pertaining to the last meals consumed (“last supper” effect). In primate feeding experiments, microwear features formed within hours, suggesting rates of turnover within one to two weeks. As DMT formation experiments testing the persistence of microwear three-dimensionally (textures) are still lacking, we test how quickly DMTs form and pr…

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The way wear goes: phytolith-based wear on the dentine–enamel system in guinea pigs (Cavia porcellus)

The effect of phytoliths on tooth wear and function has been contested in studies of animal–plant interactions. For herbivores whose occlusal chewing surface consists of enamel ridges and dentine tissue, the phytoliths might particularly erode the softer dentine, exposing the enamel ridges to different occlusal forces and thus contributing to enamel wear. To test this hypothesis, we fed guinea pigs (Cavia porcellus; n = 36 in six groups) for threeweeks exclusively on dry or fresh forage of low(lucerne), moderate (fresh timothy grass) or very high (bamboo leaves) silica content representing corresponding levels of phytoliths. We quantified the effect of these treatments with measuremen…

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Supplemental Material from The way wear goes: phytolith-based wear on the dentine–enamel system in guinea pigs (Cavia porcellus)

Additional table for individual tooth measurements as well as graphs illustrating tooth structure, tooth measurements and buccal tooth height.

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Dust and grit matter: abrasives of different size lead to opposing dental microwear textures in experimentally fed sheep (Ovis aries)

ABSTRACT External abrasives ingested along with the herbivore diet are considered main contributors to dental wear, though how the different sizes and concentrations of these abrasives influence wear remains unclear. Dental microwear texture analysis (DMTA) is an established method for dietary reconstruction which describes a tooth9s surface topography on a micrometre scale. The method has yielded conflicting results as to the effect of external abrasives. In the present study, a feeding experiment was performed on sheep (Ovis aries) fed seven diets of different abrasiveness. Our aim was to discern the individual effects of size (4, 50 and 130 µm) and concentration (0%, 4% and 8% of dry mat…

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Dental wear at macro- and microscopic scale in rabbits fed diets of different abrasiveness: A pilot investigation

To differentiate the effects of internal and external abrasives on tooth wear, we performed a controlled feeding experiment in rabbits fed diets of varying phytolith content as an internal abrasive and with addition of sand as an external abrasive. 13 rabbits were each fed one of the following four pelleted diets with different abrasive characteristics (no phytoliths: lucerne L; phytoliths: grass G; more phytoliths: grass and rice hulls GR; phytoliths plus external abrasives: grass, rice hulls and sand GRS) for two weeks. At the end the feeding period, three tooth wear proxies were applied to quantify wear on the cheek teeth at macroscopic and microscopic wear scales: CT scans were obtained…

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Use of running plates by floor housed rats: A pilot study

The outfit of husbandry facilities of, and the enrichment provided for, experimental rodents plays an important role in the animals’ welfare, and hence also for the societal acceptance of animal experiments. Whether rats and mice benefit from being provided with running wheels or plates is discussed controversially. Here we present observations from a feeding experiment, where rats were provided a running plate. As a pilot study, six identical cages, with three animals per cage, were filmed for six days, and the resulting footage was screened for the number of bouts and the time the animals spent on the plates. The main activities observed on the plate in descending order were sitting (18.…

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Everything matters: Molar microwear texture in goats (Capra aegagrus hircus) fed diets of different abrasiveness

There is an ongoing discourse about whether or not external abrasives influence the microscopic wear in herbivore teeth, including a statement that “dust does not matter”. We submitted the maxillary and mandibular second molar of 28 goats (Capra aegagrus hircus) to dental microwear texture analysis (DMTA). The study animals were divided into four groups, which received diets of increasing phytolith-based abrasiveness (L: lucerne based pellets, very low phytolith abrasion diet, acting as control; G: grass-based pellets, medium abrasive phytolith diet; GR: grass and rice husk pellets, high abrasion phytolith diet), or a diet with added external abrasives (GRS: the GR diet with add…

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