The TRIDENT project explores the ecology of extant and extinct mammals based on their dental wear. A model based on domestic sheep allows the direct correlation of dental wear with diet. This proxy is the key-tool of the TRIDENT project to explore present and past environmental changes.
The TRIDENT project aims to describe how mammals cope and have coped with present and past climate changes. Here, we focus on the diet of herbivorous mammals because the vegetation is the very element in a given ecosystem to be affected by climate change. To track diet (and its changes through Time) for extinct and extant species, a single proxy is here used: dental microwear texture analysis.
Advances in recent surface profilometers and in analytical tools are coupled with a controlled food testing on 180 sheep. The development of this unique tool will enable us to characterize the diet of extant and extinct herbivorous mammals. At this point, the grass component in the diet of a given antelope can be quantified. Applied on a whole population, this approach provides a reliable paleoenvironmental proxy.
When palaeontologists, agronomists, and tribologists collaborate. The TRIDENT project has generated a dual dataset combining diet and dental microwear textures of sheep. This dataset then provides a model to explore the ecology of extinct and extant mammals.
Is the European Bison a refugee species? Dental microwear texture analysis of the European bison from Bialowieza, Poland, shows that its diet, highly dominated by browse, is actually forced by conservation management practices; bison tend to graze in open areas when they are able to disperse out the forest.
Antelopes to track our past. The dental microwear texture analysis on fossil antelopes from the Omo valley, Ethiopia, is an environmental proxy to assess the tree cover and its changes from 3 to 2 million years. Together with other proxies, dental microwear texture analysis aims at describing the environmental context in which the first occurrence of the genus Homo took place in Africa.
To explore cryptic mammals. As surprising as this may seem, each year biologists discover new species, including large-sized mammals. The ecology of these mammals, or indeed the ecology of more discreet and difficult to observe species, remains largely unknown. Thus, the models developped by the TRIDENT project can be applied to dental remains of such species like the European bison, the okapi or even Walter's duiker, a new species from Benin which has been recently described.
A tool to explore our past. The application of the models generated by the TRIDENT project on fossil taxa appears as self-evident in order to to assess the dietary habits of extinct species. Our first focus is the antelopes that have co-occured with early human ancestors in Africa. However, we will go further and apply dental microwear texture analysis on early hominins as well.
At the halfway mark, TRIDENT members have produced 3 publications and 4 congress short communications. Moreover, since October 2014 a PhD student and two Masters students in palaeontology contribute to the progress of the TRIDENT project.
Among our scientific output, the dental microwear analysis on the European bison and deer from the Bialowieza forest in Poland has attracted significant interest in the ecologist and conservationist community. In that study, we attest that the European bison has a diet impoverished in grasses and rich in browse when it occupies forested habitats. However, when populations have the opportunity to spread outside the forest, the dental microwear analysis concludes that these bison include more grasses in their diet. Such an outcome has important implications on conservation management strategies in Eastern Europe.
TRIDENT is an interdisciplinary project combining human and technic competences in agronomy (Mourier Farm Station), tribology (Institut Pprime) and paleontology (iPHEP). TRIDENT aims at investigating the ecology of herbivorous mammals through dietary behaviour analysis. For this, the project will develop dietary reconstruction models thanks to new technical advances of 3D Dental Microwear Texture Analysis (3D-DMTA) applied to a dataset resulting from an ambitious controlled-food testing on domestic sheep.
The controlled-food testing will be conducted at the Mourier Farm Station over 6 months on 120 sheep fed on different known amounts of grasses, forbs and fruits. Sheep dental microwear data acquired through in vivo dentition molding will be analyzed in collaboration with the Institut Pprime with a newly acquired dual-core non-contact 3D surface profilometer, a key for performing state-of-the-art 3D dental tribology analyses. This will result in creating a large and unique dual-data set combining food composition and 3D Dental Microwear Textures for the tested sample.
TRIDENT will use this data to explore for the very first time the effects of several parameters on dental microwear textures: exact food composition, food physicochemical properties, dental microwear turnover, and mode of samplings (randomly, biased) for simulating the seasonal mortality in the wild. Unprecedented understandings of the factors ruling microwear texture formation will emerge. From this, a set of models will be set for precisely characterize the feeding spectrum of a given species.
TRIDENT will then use this tool to investigate the diversity and spatiotemporal variability of ecological niches through three case studies selected for the high quality of their available data and the congruence with iPHEP research topics.
The first application of the 3D-DMTA taking into account the explored models will aim at depicting the ecological niche partitioning among sympatric present-day ruminants at the Bialowieza Primeval Forest in Poland. This case study based on a relatively pristine community will be a critical comparative case for paleocommunity analyses, and in addition will have implications for conservation politics of the European Bison, the emblematic mammal of Bialowieza.
The second application will aim at evaluating spatial variation in diet and thus ecological plasticity of a ruminant, a particularly important dimension of paleoecological reconstructions. The studied case will be that of the small duiker (Philantomba sp.) dispersed along ecological gradients in the African forest. This antelope feeds mainly on fruits, a resource which is affected by habitat reduction due to anthropic pressures.
The third application will focus on a fossil case study. We will consider the reduncine antelopes from the Plio-Pleistocene deposits of the Omo valley, Ethiopia. We will explore the effects on the diet of these abundantly preserved ruminants of an extremely well-recorded environmental change that occurred 2 My ago. This analysis will have implications on the understanding of evolution in African herbivore paleocommunities.
Finally, TRIDENT will aim at promoting the 3D-DMTA to a large audience beyond basic research community. @-TRIDENT will allow this as well as it will guarantee post-project longevity. @-TRIDENT will be a sharing web interface on which development in analytic tools and software including tutorials, data issued from the controlled-food testing, as well as application on cases studies will be uploaded for students and researchers interested in the wide fields of ecology, conservation, agronomy, tribology, and performing basic or applied, academic or private research.
To sum up, TRIDENT has the ambition to build, apply and share models for the development of the 3D-DMTA in ecology and paleontology. Getting together agronomists, tribologists, and paleontologists will make possible to overpass any limits in the course of TRIDENT.
Monsieur Gildas Merceron (Institut de Paléoprimatologie, Paléontologie Humaine : Evolution et Paléoenvironnements) – email@example.com
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
iPHEP Institut de Paléoprimatologie, Paléontologie Humaine : Evolution et Paléoenvironnements
Help of the ANR 279,999 euros
Beginning and duration of the scientific project: September 2013 - 42 Months