Evolution and specialization of dental morphology in the Neotropical frugivore bat subfamily Stenodermatinae (Chiroptera, Phyllostomidae)

• Ano de defesa: 2025
• Autor(a) principal: Paes, Juliano Alfenas Silva Valente
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Biologia Animal
• Palavras-chave em Português: Morcegos - Evolução; Stenodermatinae; Animais frugívoros; Dentes - Evolução; Dente canino; CIENCIAS BIOLOGICAS
• Link de acesso: https://locus.ufv.br/handle/123456789/34872; https://doi.org/10.47328/ufvbbt.2025.755

Bats exhibit a wide variety of diets that are associated with modifications in the cranium, masticatory muscles, and dental patterns. Teeth are durable structures with high morphological variability, closely related to feeding strategy and habits. The consumption of fruits led to the specialization of the dental structure in two bat groups: Pteropodidae in Afro-Eurasia and Stenodermatinae in the Americas. This frugivorous pattern in Stenodermatinae has prompted several studies on mechanical implications and dental development, but few have addressed the evolutionary transition from the ancestral insectivorous pattern. The present study investigates the evolution and specialization of dental morphology in this clade, aiming to reconstruct the evolutionary history of its characters and infer their functional implications in Stenodermatinae and its subgroups. For this purpose, this work analyzes 66 morphological characters using a standardized nomenclature for the upper and lower teeth in 11 of 19 genera of Stenodermatinae and five outgroup taxa, mapped onto a molecular phylogeny using the parsimony criterion. In addition to mapping synapomorphies, it assesses the consistency index (CI) and retention index (RI) of characters related to their general shape, presence of cusps, cristae, and cingula, as well as their overall arrangement in the dental arcade. The ancestral state reconstruction analysis maps the transformations of each character throughout the evolutionary history and reveals a high level of homoplasy (CI = 0.423), consistent with the evolutionary plasticity of the group, but also a strong phylogenetic signal (RI = 0.800), validating the use of these characters for clade diagnosis. The study details a series of key transformations associated with frugivory, such as the reduction in canine robustness, the specialization of the premolars, and the labial displacement of the molar cusps. Additionally, the work describes the emergence of accessory structures in Stenodermatinae, such as the mesoconule and its associated cristae, which increase the complexity and efficiency of the occlusal surface, and correlates cusp morphology with specific diets of hard (durophagy) or soft (jusophagy) foods. The presence of cingula is interpreted as a biomechanical reinforcement structure, while diastemata and occlusal gaps are analyzed as adaptations for fruit handling and the ejection of its byproducts, such as fibers and seeds. This work demonstrates that the dentition of Stenodermatinae evolved from an ancestral insectivorous pattern into a complex and highly derived set of characters, acting as a record of the group's adaptive history and being fundamental to understanding the macroevolutionary processes that led the Stenodermatinae to become one of the most diverse and successful groups of Neotropical bats. Keywords: ancestral state reconstruction; cusps; mesoconule; synapomorphies