Predicting hydric and thermic balance in caviomorph rodents through nasal turbinals morphometry: Impact of life habits.

Abstract

Nasal turbinals are key osseous structures for air conditioning and olfaction in mammals, with their morphology reflecting both ecological adaptations and evolutionary history. This study evaluates how climatic gradients and locomotor strategy (subterranean or surface dwelling species) influence turbinal complexity in caviomorph rodents. Using microCT imaging, we quantified respiratory (RZ) and olfactory (OZ) turbinal morphology across eight caviomorph rodents and two outgroups from xeric, mesic, and generalist habitats, including subterranean and surface-dwelling species. Our results revealed that xeric-adapted subterranean species exhibited significantly expanded RZ surface areas and greater structural complexity, consistent with enhanced water retention demands in arid environments. While surface-dwelling species showed larger absolute OZ areas compared to subterranean taxa, this difference became non-significant after accounting for body size, suggesting olfactory structures are less influenced by locomotor strategy than by allometric or phylogenetic factors. Respiratory turbinals appeared more variable across habitats, whereas olfactory turbinals showed comparatively conserved morphology among ecological groups. This pattern could reflect differing evolutionary pressures acting on thermoregulatory versus sensory systems in rodents. The observed trade-off between respiratory efficiency and olfactory capacity suggests how multiple selective forces may shape anatomical specialization in response to environmental challenges. These findings provide new insights into functional constraints governing nasal evolution, proposing a framework for interpreting ecological adaptations in caviomorphs. Our study illustrates how integrating quantitative morphometrics with ecological data can elucidate complex structure-function relationships in mammalian anatomy.