Taxonomic identification of suids, bovids, and caprines through comparative scanning electron microscopy of prismatic structure tooth enamel from prehistoric northern Italian Alpine sites

Taxonomic identification of fragmentary faunal assemblages remains a key challenge in zooarchaeology, particularly when diagnostic macromorphological traits are absent or ambiguous. Here we test the potential of SEM-based enamel prism microstructural morphometrics as a taxonomic proxy in archaeological contexts, focusing on materials from the Adige Valley (northern Italy). A total of 64 adult permanent teeth from La Vela and Riparo Gaban (Neolithic, with additional Bronze Age levels from Riparo Gaban) were analyzed, encompassing Bos taurus (n = 6), Sus sp. (n = 28), and medium-sized herbivores (M–S herb. sp., n = 30). Sediment pH was measured to evaluate preservational conditions and potential surface alteration; both sites showed slightly acidic values (mean pH ≈ 5,9–6,6). Enamel surfaces were imaged with a desktop SEM (Phenom XL), and prisms were quantified and measured within standardized acquisition fields. For each prism, Dmax, Dmin, perimeter, and area were estimated, and six derived ratios were computed; to avoid pseudoreplication, all analyses were performed at the tooth level using summary descriptors (mean, SD, median, p10–p90, CV). Results show clear interspecific separation in prism morphometrics: Bos taurus displays markedly larger absolute values for all primary variables, Sus sp. occupies intermediate ranges, and M–S herb. sp. shows the lowest absolute values, with generally moderate within-taxon variability. One and Two-way ANOVA indicates an extremely strong Species effect across all variables and ratios, whereas ToothType and Species×ToothType interactions are not significant in the present dataset. Ratio variables—especially Dmax/Dmin and Perim/Area—provide particularly strong discrimination. A targeted ZooMS test (one specimen with associated bone) supported refinement of macroscopic identification. Overall, these findings support the feasibility of enamel prismatic structure morphometrics as a minimally invasive tool for taxonomic discrimination in archaeological teeth, while highlighting the need for expanded and more balanced sampling to further test within-taxon dental variation and assess performance across different soil chemistries.