About inter- and intra-specific variability of dental microwear texture in rodents: Study of two sympatric Proechimys (Echimyidae) species from the Cacao locality, French Guiana (original) (raw)
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Dental microwear texture analysis in mammalian ecology
1. Neoecology and paleoecology both seek to answer the same questions, albeit using different material, at different time scales and with different limitations. Nevertheless, too often, neoecologists neglect paleoecology, and paleoecologists only use neoecology as a baseline for actualism. One reason for this is the lack of tools that can be applied to both fields. 2. This is a review of the contributions to both neoecology and paleoecology of three-dimensional (3D) dental microwear texture analysis (DMTA), a method that can act as a bridge between these fields. 3. DMTA studies can be grouped according to the type of ecological questions researchers seek to answer: specific ecology, intra-specific ecology, niche partitioning and dietary overlap, and ecology over time. The first question has been the main focus of research; the other three were only superficially studied. 4. In this review, selected examples will be presented to demonstrate that DMTA, as one of the few tools that can be applied to both modern and fossil samples, has been used to address key ecological questions in mammalian neoecology and paleoecology. 5. With the wide range of neoecological and paleoecological questions that DMTA can answer, it is clear that this methodology will be used increasingly in the future, possibly in combination with other ecological proxies.
Enamel microwear in caviomorph rodents
Journal of Mammalogy, 2008
We developed a new data set of enamel microwear for extant caviomorph rodents (i.e., South American hystricognaths) and inferred the diet of an extinct taxon, Neoreomys australis, from data on microwear. To evaluate frequencies of wear features (pits and scratches) in caviomorphs, we employed low-magnification microwear, which has been used successfully by others to distinguish among the diets of ungulates, primates, and sciurid rodents. We developed 3 broad dietary categories for caviomorphs based on behavioral observations reported in the literature: fruit-leaf, fruit-seed, and grass-leaf. Caviomorphs in general all exhibited wear features indicative of processing hard objects (e.g., seed predation, eating hard fruits, and consuming exogenous grit). Among our grass-leaf group, we identified an exogenous-grit subgroup that included fossorial and dust-bathing taxa. We used a discriminant function analysis of wear features to examine post hoc classification of the caviomorph taxa into the 3 dietary categories. Ours is the 1st study to quantify the distribution of microwear features among modern caviomorph rodents; it has the potential to clarify the diets of modern forms that have little behavioral data as well as to infer the diets of extinct species.
Dental microwear texture and anthropoid diets
American Journal of Physical Anthropology, 2012
Dental microwear has long been used as evidence concerning the diets of extinct species. Here, we present a comparative baseline series of dental microwear textures for a sample of 21 anthropoid primate species displaying interspecific and intraspecific dietary variability. Four dental microwear texture variables (complexity, anisotropy, textural fill volume, and heterogeneity) were computed based on scale-sensitive fractal analysis and high-resolution three-dimensional renderings of microwear surfaces collected using a white-light confocal profiler. in Wiley Online Library (wileyonlinelibrary.com).
Integrative zoology, 2016
Dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil vertebrates. Nevertheless, some studies have recently questioned the efficacy of this approach, suggesting that aspects of habitat unrelated to food preference, especially environmental grit load, might have a confounding effect on microwear patterning that obscures the diet signal. Here we evaluate this hypothesis by examining microwear textures of three extant sympatric rodent species that vary in diet breadth and are found in a variety of habitat types: Mastomys coucha, Micaelamys namaquensis, and Rhabdomys pumilio. We sample each of these species from three distinct environmental settings in southern Africa that differ in rainfall and vegetative cover: Nama-Karoo shrublands (semi-desert) and Dry Highveld grasslands in the Free State Province of South Africa, and Afromontane (wet) grasslands in the highlands of Lesotho. While differences between habitat types ar...
Dental microwear and diet in Venezuelan primates
American Journal of Physical Anthropology, 1992
Recent microwear analyses have demonstrated that wear patterns can be correlated with dietary differences. However, much of this work has been based on analyses of museum material where dates and locations of collection are not well known. In view of these difficulties, it would be desirable to compare microwear patterns for different genera collected from the same area at the same time.The opportunity to do this was provided by the collections of the Smithsonian Venezuelan Project (Handley, 1976), in which multiple primate genera were collected from the same humid tropical forest sites within the same month. The monkeys represent a wide range of dietary preferences, and include Saimiri, Cebus, Chiropotes, Ateles, Aotus, Pithecia, and Alouatta.As in previous microwear analyses, epoxy replicas were prepared from dental impressions, as described by Rose (1983) and Teaford and Oyen (1989). Two micrographs were taken of facet 9 on an upper second molar of each specimen. Computations and...
A preliminary analysis of dental microwear as a proxy for diet and habitat in shrews
mammalia, 2000
Dental microwear has been shown to reflect diet in a broad variety of fossil mammals. Recent studies have suggested that differences in microwear texture attributes between samples may also reflect environmental abrasive loads. Here, we examine dental microwear textures on the incisors of shrews, both to evaluate this idea and to expand the extant baseline to include Soricidae. Specimens were chosen to sample a broad range of environments, semi-desert to rainforest. Species examined were all largely insectivorous, but some are reported to supplement their diets with vertebrate tissues and others with plant matter. Results indicate subtle but significant differences between samples grouped by both diet independent of environment and environment independent of diet. Subtle diet differences were more evident in microwear texture variation considered by habitat (i.e., grassland). These results suggest that while environment does not swamp the diet signal in shrew incisor microwear, studies can benefit from control of habitat type.
American Journal of Physical Anthropology, 1984
Studies of dental microwear have been used to relate tooth form to function in a variety of recent and extinct mammals. Probably the most important aspect of microwear analysis is the possibility of using it to deduce the diet of extinct animals. Such deductions must be based on comparative studies of modern species with known diets, but to date, only qualitative studies have been attempted and all have been based on small samples. Here we report quantitative differences in dental microwear between primate species that are known to have different diets. Occlusal facets with different functions have previously been shown to exhibit different microwear patterns. However, the differences between facets of one species are shown to be far less than those between homologous facets of different species. Study of seven species of extant primates shows that enamel microwear can be used to distinguish between those with a mainly frugivorous diet and those with a mainly folivorous one. Microwear can also distinguish hard-object feeders from soft-fruit eaters. The microwear of Miocene Sivapithe cus indicus cannot be distinguished statistically from that of the chimpanzee, but it is different from that of the other species. On this evidence S. indicus was not a hard-object feeder and the adaptive significance of its thick molar enamel is a t present unknown.
Dietary characteristics and environmental variables are important selective factors directing ecological diversification in rodents. On Madagascar, the introductions and spread of the commensal black rat (Rattus rattus) can be seen as example cases to study dietary niche occupation and dietary adaptation in an insular environment. We investigate how tooth wear as a measure of dietary adaptation of black rats differs between four distinct habitats (village, manioc fields, spiny forest, and rainforest) with different dietary resources. We use the 3D surface texture analysis (3DST, using 30 parameters according to ISO 25178) as a measure of dietary abrasiveness. 3DST is applied on the occlusal surface of the upper first molar of 37 black rat specimens. The rainforest sample displays less rough and less voluminous surface textures compared to the village samples as indicated by smaller values for height parameters (Sa, Sp, Sq), inverse areal material ratio (Smc), and volume parameters (Vm, Vmc, Vmp, Vv, and Vvc). We therefore rank sampling areas from highest to lowest abra-siveness (village>manioc fields/spiny forest>rainforest). The rats from villages and rainforest differ to such an extent that one could have interpreted them to belong to different species. This indicates a high degree of variability in terms of ingesta abrasiveness. Furthermore, the pronounced difference between rats from human habitations compared to rats from associated fields or natural vegetation is interpreted to clearly indicate shifts in dietary niche occupation in relation to human impact.
Dental microwear variation in complete molars of Loxodonta africana and Elephas maximus
Quaternary international, 2007
Dental microwear analysis is an important addition to the field of paleoecology, and has proven useful for inferring dietary preferences in extant and extinct species. New techniques involving the use of low-magnification light microscopy have become very popular for use with large specimens that pose logistical problems for analysis with traditional scanning electron microscopy. In this study, the dental microwear of two complete molars from the extant elephants, Loxodonta africana and Elephas maximus was examined using low magnification light microscopy. The African elephant molar had a higher percentage of scratches versus pits when compared to the Asian elephant. Previous studies on elephant teeth have examined only a sample area of each lamella, and based on this study, much variation is present within a single molar from anterior to posterior lamellae as well from buccal to lingual sides of these plates, and so analysis of a sample area of enamel may not be providing consistent information on diet preference. r
PalZ, 2021
Low magnification dental microwear analysis is a widespread dietary proxy for palaeoenvironmental analyses. The limitations of the method, such as observer bias or variation of microwear scars between different tooth positions, are still not quite understood. This study aims to reveal that reproducibility and variability of low magnification dental microwear is better, than it was previously thought. The main focuses of this study were differences between results produced by independent observers, and individual variability of the wear features on different teeth of the same specimen. To approach these issues, the microwear of 1944 0.4 × 0.4 mm areas on every right molar and premolar (144 teeth of 12 extant ungulate specimens) was quantified. Reproducibility and interobserver error was tested by calculating the intraclass correlation coefficients for the scores produced by the observers. The microwear features of each tooth were characterized by the mean, median, standard deviation,...