A review of fossil and recent Desmaninae (Talpidae, Insectivora)

Abstract

Numerous new finds have been described since Schreuder published "A revision of the fossil water-moles (Desmaninae)" in 1940. In addition to these described assemblages there are many undescribed collections in various institutions and museums. Most of the finds are from isolated localities scattered over Europe. This new revision of the subfamily Desmaninae is based primarily on the collection of the Institute of Earth Sciences of the Rijksuniversiteit Utrecht, which includes many assemblages of desmanine moles. As well as our own collections, however, we have been able to study many assemblages put at our disposal by colleagues from other institutions. We have also made use of published data from various countries. Nearly all the material studied is allocated to one of the following three genera, i.e. the newly erected genus Dibolia, characterized by its small size and a bifid straight first upper incisor, Galemys, characterized by its small size and a pointed curved first upper incisor and Desmana, characterized by its medium to large size and a pointed curved first upper incisor. A fourth genus belonging to the Desmaninae, the genus Mygalinia, characterized by its very small size and aberrant mandibular ramus, is not represented in the material studied. The material from Hammerschmiede, described by Mayr and Fahlbusch (1975), although apparently belonging to a desmanine mole, could not be assigned to any of the known genera. A new classification of the subfamily is proposed. In this classification the genera are distinguished on the basis of the morphology of the i1 and the I1 and the overall size, whereas the species are distinguished by the absolute length and more in particular the relative length of six selected teeth, viz. p2, p3 and p4 and C, P2 and P3. In the genus Dibolia nine species are distinguished, in the genus Galemys four species and in the genus Desmana six species. In order to facilitate the determination of water-moles a general description of all desman teeth is given. A short discussion of the various types of lower jaw and their possible function, as well as a description of the chevrons (tail bones), which are indicative of an aquatic life, are added. The results of the measurements, a detailed description of the teeth used in the classification for each locality and some comments on the age of the assemblages are included.