"Filogenia, biogeografía y adaptación ecológica en los Andes de los roedores del género Thomasomys Coues, 1884 (Rodentia: Cricetidae)"

• Autor: Ruelas Pacheco, Dennisse Cinthya
• Formato: tesis doctoral
• Fecha de Publicación: 2024
• Institución: Universidad Peruana Cayetano Heredia
• Repositorio: UPCH-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.upch.edu.pe:20.500.12866/16458
• Enlace del recurso: https://hdl.handle.net/20.500.12866/16458
• Nivel de acceso: acceso embargado
• Materia: Adaptation; Rodentia; Systematics; South America; Tropical Andes; https://purl.org/pe-repo/ocde/ford#1.05.06; https://purl.org/pe-repo/ocde/ford#1.06.07; https://purl.org/pe-repo/ocde/ford#1.06.11; https://purl.org/pe-repo/ocde/ford#1.06.13

The genus Thomasomys, a key genus within the Thomasomyini tribe of the Sigmodontinae subfamily, is a focal point for understanding the phylogeny, biogeography, and ecological adaptation of Andean rodents. As the most diverse genus within the Sigmodontinae, Thomasomys includes 51 valid species and numerous undescribed ones, predominantly inhabiting Neotropical montane forests and paramos. Its distribution, however, excludes regions like the Guiana Shield, lowland tropical forests, deserts, and oceanic islands. Conflictive findings between early molecular phylogenetic analyses and morphological studies highlight the necessity for an integrated approach encompassing genetic, molecular, and morphological research. This research delves into Thomasomys complex taxonomic background, phylogenetic relationships, species diversity, and morphological adaptations, shedding light on its evolutionary history and ecological adaptations in the challenging Andean habitats. The research encompasses three chapters. Chapter 1 reveals an underestimated species diversity, confirming the monophyly of the genus. The analyses identified ten major clades, demonstrating a complex phylogenetic structure with paraphyletic or polyphyletic relationships among species and challenging the monophyly of some species groups such as Cinereus, Aureus, Gracilis, and Incanus. Unilocus species delimitation methods indicated a higher number of putative species compared to the current taxonomy. It also emphasizes the biogeographical importance of the Marañón area as a geographical barrier influencing species distribution and speciation within Thomasomys. Chapter 2 explores the turbinal bone adaptations in Thomasomys species. It suggests that these adaptations are closely tied to elevation and environmental challenges, with a significant positive allometric relationship observed between turbinal surface areas and skull length. Chapter 3 introduces a new genus distinct from Thomasomys and describes three new species endemics to the central Peruvian Yungas. This discovery challenges the traditional taxonomic composition of the Thomasomyini tribe, the morphological delimitation of the genera that comprise it, and puts into debate the phylogenetic position of Rhagomys. Together, these chapters shed light on the complex evolutionary history and ecological adaptations of the Thomasomys genus, emphasizing the need for integrative research approaches to fully understand the complexities of Andean rodent biodiversity and adaptation.