CARACTERIZAÇÃO CITOGENÉTICA E CRANIANA DOS ROEDORES SIGMODONTÍNEOS DO SUL DO GOIÁS, BRASIL CENTRAL

Abstract

Brazil has one of the greatest biodiversities in the world, with 785 recorded mammalian species, approximately 43% of which are small non-volant mammals. Despite the high representativeness of this group, their diversity and distribution patterns in the Cerrado remain poorly understood. The identification of some taxa within the order Rodentia is challenging due to their high morphological similarity. In this context, the integrated analysis of cytogenetic and morphological data, including craniometric information, has proven to be an effective tool for accurate taxonomic identification. Scientific collections play a crucial role in assessing diversity and supporting mammalian taxonomic studies. The Mammal Collection of the State University of Goiás (CMUEG), located in southern Goiás, has been essential for advancing the knowledge of the region’s mammalian fauna. It is the only collection in the region registered with the Committee of Mastozoological Collections. This study provides a detailed evaluation of the small rodents housed in the CMUEG through karyotype descriptions and morphometric analyses, including measurements and assessments of external and craniodental morphology. The approach aims to improve the accuracy of sigmodontine rodent identifications. A total of 68 skulls and dentitions were analyzed, along with karyotypes from 27 specimens, belonging to the tribes Akodontini, Oryzomyini, Phyllotini, and Thomasomyini. Morphometric and qualitative differences were observed in morphologically similar species, such as Calomys expulsus and Calomys tener, as well as between Oligoryzomys mattogrossae and Oligoryzomys nigripes. Additionally, karyotypes of Necromys lasiurus, Hylaeamys megacephalus, Oecomys catherinae, Oecomys cleberi, Oligoryzomys mattogrossae, Calomys expulsus, and Rhipidomys macrurus were presented. The results reinforce the importance of scientific collections and integrative approaches for the accurate taxonomic identification of small mammals, contributing to the quality and integrity of biodiversity data in the region.