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 (…

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…

Root growth compensates for molar wear in adult goats (Capra aegagrus hircus)

One reason for the mammalian clade’s success is the evolutionary diversity of their teeth. In herbivores, this is represented by high‐crowned teeth evolved to compensate for wear caused by dietary abrasives like phytoliths and grit. Exactly how dietary abrasives wear teeth is still not understood completely. We fed four different pelleted diets of increasing abrasiveness (L: Lucerne; G: grass; GR: grass and rice husks; GRS: grass, rice husks, and sand) to four groups of a total of 28 adult goats, all with completely erupted third molars, over a six‐month period. Tooth morphology was captured by medical computed tomography scans at the beginning and end of the controlled feeding experiment, …

Why ruminating ungulates chew sloppily: Biomechanics discern a phylogenetic pattern.

Altres ajuts: "Beatriu de Pinos" 2014 - BP-A 00048 There is considerable debate regarding whether mandibular morphology in ungulates primarily reflects phylogenetic affinities or adaptation to specific diet. In an effort to help resolve this debate, we use three-dimensional finite element analysis (FEA) to assess the biomechanical performance of mandibles in eleven ungulate taxa with well-established but distinct dietary preferences. We found notable differences in the magnitude and the distribution of von Mises stress between Artiodactyla and Perissodactyla, with the latter displaying lower overall stress values. Additionally, within the order Artiodactyla the suborders Ruminantia and Tylo…

Electronic Supplement from Dental microwear texture reflects dietary tendencies in extant Lepidosauria despite their limited use of oral food processing

Variability of dental microwear along the tooth row, dietary data and information on specimens, statistics, parameter description, PCA details

Forage silica and water content control dental surface texture in guinea pigs and provide implications for dietary reconstruction.

Significance Ingesta leave characteristic wear features on the tooth surface, which enable us to reconstruct the diet of extant and fossil vertebrates. However, whether dental wear is caused by internal (phytoliths) or external (mineral dust) silicate abrasives is controversially debated in paleoanthropology and biology. To assess this, we fed guinea pigs plant forages of increasing silica content (lucerne < grass < bamboo) without any external abrasives, both in fresh and dried state. Abrasiveness and enamel surface wear increased with higher forage phytolith content. Additionally, water loss altered plant material properties. Dental wear of fresh grass feeding was similar to lucerne brows…

Dietary divergence in space and time – Lessons from the dwarf-goat Myotragus balearicus (Pleisto-Holocene, Mallorca, Spain)

8 pages; International audience; Newly colonised, isolated habitats, like islands, provide diverse niches to be filled and are prone to facilitate ecological separation which might lead to an adaptive radiation. Examples of such radiations can be found in the Mediterranean for the genera Candiacervus (Crete), Nesogoral (Sardinia) and Hoplitomeryx (Gargano). A different strategy to cope with limited resources on islands is generalism. We test whether populations of the endemic bovid Myotragus balearicus from two sites and Pleistocene as well as Holocene levels on Mallorca island displays ecological separation indicated by diet, or whether the species shifted its dietary trait towards general…

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…

Dental microwear texture analysis on extant and extinct sharks : Ante- or post-mortem tooth wear?

Sharks are apex-predators that play an important role in past and present aquatic food webs. However, their diet - especially in extinct species - is often not well constrained. Dental microwear texture analysis (DMTA) has been successfully applied to reconstruct diet and feeding behaviours of different aquatic and terrestrial vertebrates. However, unlike in mammals, food-to-tooth contact in sharks is rather limited because only larger prey is manipulated before swallowing. Together with a fast tooth replacement rate, this reduces wear on individual teeth. Here, we present an explorative study of dental microwear texture on extant and extinct sharks to test whether ante-mortem wear is relat…

Feeding ecology and chewing mechanics in hoofed mammals: 3D tribology of enamel wear.

11 pages; International audience; Large herbivorous mammals have evolved chewing systems capable of processing a large variety of structurally diverse foods. Three-dimensional (3D) surface texture parameters are applied to investigate wear mechanisms related to tooth morphology, food source, and chewing dynamics. We tested 46 industrial 3D surface texture parameters for their capability to robustly indicate specific biomechanics in two grazing (Blue Wildebeest and Grevy's Zebra) and two browsing (Giraffe and Black Rhinoceros) ungulate mammals. These species inhabit sub-Saharan Africa and represent foregut and hindgut fermenters. The results did not indicate a wavelength threshold that can c…

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…

First application of dental microwear texture analysis to infer theropod feeding ecology

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 is analysed in extant specimens, while isolated teeth are lumped together in fossil datasets. It is therefore important to test whether dental microwear texture (DMT) is tooth position specific and, if so, what causes the differences in 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) or pelleted diets with and without mineral abrasives (frequently encountered by herbivorous mammals in natu…

The good, the bad and the ugly – A visual guide for common post-mortem wear patterns in vertebrate teeth

Abstract Dental microwear texture analysis (DMTA) is a common wear proxy using dental wear features to reconstruct diet in extant and extinct taxa. Dietary reconstructions of extinct species can be biased due to post-mortem mechanical modification of the dental surface. These post-mortem surface alterations can be caused by material loss after death, or as the result of burial, excavation, or preparation processes. In this study, we explore post-mortem surface alterations that occur during excavation, preparation, and conservation processes. We present a first general overview of unsuitable and suspicious dental surface scans and describe them both qualitatively and quantitatively using den…

Shape, size, and quantity of ingested external abrasives influence dental microwear texture formation in guinea pigs

Food processing wears down teeth, thus affecting tooth functionality and evolutionary success. Other than intrinsic silica phytoliths, extrinsic mineral dust/grit adhering to plants causes tooth wear in mammalian herbivores. Dental microwear texture analysis (DMTA) is widely applied to infer diet from microscopic dental wear traces. The relationship between external abrasives and dental microwear texture (DMT) formation remains elusive. Feeding experiments with sheep have shown negligible effects of dust-laden grass and browse, suggesting that intrinsic properties of plants are more important. Here, we explore the effect of clay- to sand-sized mineral abrasives (quartz, volcanic ash, loess,…

Post-mortem alteration of diet-related enamel surface textures through artificial biostratinomy: A tumbling experiment using mammal teeth

In the fossil record, teeth are often all that remains of a fossil organism. Dental microwear texture analysis (DMTA) is a common proxy for diet using dental wear features at the &mu;m-scale, enabling comparative and quantitative assessments of various feeding traits in extant and extinct species. In extinct species, original diet-related dental wear features may be overprinted by post-mortem alteration including fluvial transport. Here we experimentally investigate the effects of mechanical alteration on diet-related 3D enamel surface texture (3DST) patterns of different mammal teeth. Post canine teeth of Equus sp., Capreolus capreolus and Otomys sp. are tumbled in sediment-water suspensio…

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 &ldquo;dust does not matter&rdquo;. 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…

Multiproxy dietary trait reconstruction in Pleistocene Hippopotamidae from the Mediterranean islands

Abstract Geographically isolated insular species face energetic restrictions and commonly evolve adaptations that distinguish them from their mainland ancestors. During the Pleistocene, several Mediterranean islands were inhabited by now extinct Hippopotamidae. They underwent diverse changes in locomotion, dentition and body size. Based on these differences, it is supposed that they occupied different ecological niches depending on their respective faunal complexes and available resources. In this paper, we assess the paleoecology of dwarfed hippopotami from Crete, Malta, Sicily and Cyprus using a novel dental multiproxy approach. We applied dental topography analysis (SAGA-GIS) to measure …

Dental microwear texture reflects dietary tendencies in extant Lepidosauria despite their limited use of oral food processing

Lepidosauria show a large diversity in dietary adaptations, both among extant and extinct tetrapods. Unlike mammals, Lepidosauria do not engage in sophisticated mastication of their food and most species have continuous tooth replacement, further reducing the wear of individual teeth. However, dietary tendency estimation of extinct lepidosaurs usually rely on tooth shape and body size, which allows only for broad distinction between faunivores and herbivores. Microscopic wear features on teeth have long been successfully applied to reconstruct the diet of mammals and allow for subtle discrimination of feeding strategies and food abrasiveness. Here, we present, to our knowledge, the first de…

Controlled feeding experiments with diets of different abrasiveness reveal slow development of mesowear signal in goats ( Capra aegagrus hircus )

ABSTRACT Dental mesowear is applied as a proxy to determine the general diet of mammalian herbivores based on tooth-cusp shape and occlusal relief. Low, blunt cusps are considered typical of grazers and high, sharp cusps typical of browsers. However, how internal or external abrasives impact mesowear, and the time frame the wear signature takes to develop, still need to be explored. Four different pelleted diets of increasing abrasiveness (lucerne, grass, grass and rice husks, and grass, rice husks and sand) were fed to four groups of a total of 28 adult goats in a controlled feeding experiment over a 6-month period. Tooth morphology was captured by medical CT scans at the beginning and end…

Modular Wear Facet Nomenclature for mammalian post-canine dentitions

Dental wear facets on the occlusal surface of premolars and molars are traces of their main function, the mastication and therefore reflect masticatory movements and also paramasticatory (i.e. non-dietary use of teeth) behavior. Here we present the Modular Wear Facet Nomenclature applicable to most mammalian dentitions. Topographic positions of wear facets in relation to the major cusps and crests of the teeth are used to designate the areas of the occlusal surface the facets occupy (e.g. their mesial, distal, lingual, or buccal position). Previous published systems for labeling wear facets have been inconsistent with each other. Therefore, we provide a synoptic review of the most widely-us…

Post-mortem enamel surface texture alteration during taphonomic processes—do experimental approaches reflect natural phenomena?

Experimental approaches are often used to better understand the mechanisms behindand consequences of post-mortem alteration on proxies for diet reconstruction.Dental microwear texture analysis (DMTA) is such a dietary proxy, using dental wearfeatures in extant and extinct taxa to reconstruct feeding behaviour and mechanicalfood properties. In fossil specimens especially, DMTA can be biased by post-mortemalteration caused by mechanical or chemical alteration of the enamel surface. Herewe performed three different dental surface alteration experiments to assess the effectof common taphonomic processes by simplifying them: (1) tumbling in sedimentsuspension to simulate fluvial transport, (2) s…

Does silica concentration and phytolith ultrastructure relate to phytolith hardness?

Abstract Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate av…

Data from: Controlled feeding experiments with diets of different abrasiveness reveal slow development of mesowear signal in goats (Capra aegagrus hircus)

Dental mesowear is applied as a proxy to determine the general diet of mammalian herbivores based on tooth-cusp shape and occlusal relief. Low, blunt cusps are considered typical for grazers and high, sharp cusps typical for browsers. However, how internal or external abrasives impact mesowear, and the time frame the wear signature takes to develop, still need to be explored. Four different pelleted diets of increasing abrasiveness (lucerne, grass, grass and rice husks, grass, rice husks and sand) were fed to four groups of a total of 28 adult goats in a controlled feeding experiment over a six-month period. Tooth morphology was captured by medical CT scans at the beginning and end of the e…

Raw dental microwear data from Dental microwear texture reflects dietary tendencies in extant Lepidosauria despite their limited use of oral food processing

Data encloses raw dental microwear data for both dataset including individual scans for all specimens