Taxonomy of the pasts small rodents with contributions to the knowledge of the Holocene paleoenvironmental changes in northeastern Rio Grande do Sul, Brazil

Abstract

The preservation of remnants of small vertebrates is a very rare event because need that factors chemical, physical, geological and biological act in fragile bones and teeth to this not be destroyed by decomposition process and weathering. Although rare, the testimonies of such fauna are found with some frequency in excavations in rock shelters of Rio Grande do Sul State. The studies about this testimonies contribute to the understanding of the biogeographic evolution of populations of small vertebrates and often in a better understanding of the relationships and evolution of taxonomic groups of living species. Many species of small mammals are considered good environmental indicators because they have many different ecological requirements and occupy very specific niche. This knowledge also allows paleoclimatic and paleoenvironmental information is obtained by studying remnants of that group. Thus, this project aims to recognize the fauna composition of small rodents in different periods, identifying the lowest possible taxonomic level a collection of skull fragments and teeth rescued two archaeological sites, rock shelters in northeastern northeastern Rio Grande do Sul. After this step, I intend to establish a correlation between morphology and ecology of the species identified based on literature data and also existing knowledge about recent congeneric taxa, so we will can make inferences to the mid-Holocene paleoenvironmental and recent region.