Evolution and morphology of Marmota (Rodentia, Sciuridae): ontogeny and interspecific comparison of skulls of all living species

No aspect of the biology of a species should be neglected if we are to achieve a comprehensive understanding of its evolutionary history. Marmots have been thoroughly used as model organisms by eco-ethologists interested in the evolution of mammal societies. In contrast, phylogenetic and morphological studies have received less attention and have seldom involved all living species. Over the last few years, several studies have been published, which investigate morphological variation in marmots using modern morphometric techniques. These studies have improved our understanding of marmot evolution, supporting subgeneric classifications based on DNA sequences, suggesting an early occurrence of interspecific differences during ontogeny, showing the importance of allometry in the development of age-specific traits, and revealing an unexpected acceleration in the rate of morphological divergence of the youngest and most endangered marmot species, M. vancouverensis. The aim of this paper is to provide the reader with a synthetic overview of these recent advances in the study of marmot biology.