Assessing supernumerary root occurrence as a possible adaptation enhancing teeth performance in Mediterranean deer populations

Abstract

Teeth root morphology and integrity are essential to provide appropriate attachment, allowing for continuous and functional movement, with implications for adequate food processing, animal performance, and longevity. We studied the occurrence of supernumerary roots in mandibular molariform teeth of red deer ( Cervus elaphus Linnaeus, 1758) from seven separate populations spanning a range of latitudes in the Iberian Peninsula. We analyzed the influence of several factors, including sex, origin (native vs. reintroduced), lineage, and habitat, to assess extra root prevalence variations. The highest prevalence in deciduous teeth was found in pm3 (14%) and in permanent teeth in M1 (3%). We found significant differences between areas, lineages, and soil type; however, no significant relationships were found with the origin or the sex of individuals. We speculate that the high prevalence of supernumerary roots in M1 might be related to increased wear in grazers. Furthermore, we suggest that this high prevalence in deciduous teeth might be associated with a hard diet, dry climatic conditions, and a harsh weaning period, which indicate that supernumerary roots might have an adaptive value.