Shrews are among the most ancient of all living mammals. They are small and have rather unspecialized body plans, retained almost unchanged since they evolved about 45 million years ago. They appear to be extremely successful as a group in comparison to all other families of Insectivora: the living species of shrews represent approximately 80% of all insectivorans, which in turn make up some 10% of all mammmalian species extant today.

In spite of an apparent recent increase of interest in shrews and an impressive (and still accumulating) bibliography on the evolution of this fascinating group of mammals, there has been no comprehensive work that deals with current problems in shrew evolutionary research. This monograph aims to address that.