Editorial Preface to Special Issue: Understanding dental proxies of ancient diets

Vertebrate teeth are highly mineralized dermal tissues composed, principally, of bioapatite making them highly resistant to physical and chemical alteration over geologic time scales. This means that the morphology and microstructure of fossil teeth is often preserved, providing diagnostic features for taxonomic classification and enabling inferences about phylogenetic relationships. They also provide abundant information about the feeding ecology of fossil taxa, including diet, feeding behavior, local resource availability, habitat structure, and climate conditions. Tooth shape, tooth wear at different scales, dental chemistry and isotopic composition, as well as ingesta particles aggregated in dental calculus comprise important clues to reconstruct the feeding ecology of a fossil species. This special issue features 21 papers that address the use of dental proxies to infer diet and related ecological habits. Among them, a first paper compares post mortem damages on enamel surfaces with dietary-related tooth wear. Then, nine papers focus on in vivo or in vitro experimentation to test specific hypotheses. Authors address questions about taphonomic processes that may blur dietary or ecological signals, the biotic and abiotic sources of the dental wear, and the calibration of models linking diet composition to dental proxies. Eight papers explore links between dental proxies and ecology and behavior in real world contexts and focus on the study of living mammals in the wild at the individual and population scales. Among those latter studies, three integrate fossil case studies. The remaining papers address questions about niche partitioning, climate effects on local resources and their use, physiology, and the influence of diet on phenotypic selection in extinct species. As such, this special issue will stimulate further work on dental proxies and be of interest to a broad community of palaeoecologists.