What do we know about tooth weathering? A neotaphonomic study on mammals from the Argentine Pampas

Abstract

Weathering has been widely discussed in the literature and considered in taphonomic studies of fossil assem­ blages. Although bone weathering has been extensively documented, systematic analyses of dental remains are scarce, despite their abundance in the fossil record and usefulness in paleontological and archaeological studies. This contribution evaluates sub–aerial weathering in teeth. Two experiments were conducted in an open–air setting in the Argentine Pampas using specimens of Lagostomus maximus (Rodentia), Chaetophractus villosus (Cingulata), and Lycalopex gymnocercus (Carnivora), considering their morphological, compositional, and structural differences at the dental level. Experiments were initiated at the onset of winter and summer to test the influence of seasonality. We present here the results obtained after three years of continuous exposure. Molariforms with a high dentine/enamel ratio on the exposed surface, such as those of L. maximus, degraded more rapidly than those with a higher proportion of more resistant tissues, such as the “hard” orthodentine in C. villosus and enamel in Ly. gymnocercus. The onset of the seasons strongly affected the rate of deterioration, since specimens exposed from summer onward weathered more rapidly than those exposed from winter onward, driven by the higher temperatures, solar radiation, and humidity fluctuations. The results reveal taxon–specific degradation trajectories, depending on both intrinsic and extrinsic factors. The monitoring of the type and timingof modifications enabled the establishment of a qualitative classification system of weathering stages for each species. This neotaphonomic research offers a reference baseline for interpreting tooth preservation in open–air paleontological and archaeological contexts.