New species of Hispanomys (Rodentia, Cricetodontinae) from the Upper Miocene of Batallones (Madrid, Spain)

Material of Hispanomys (Rodentia, Cricetodontinae) is described from various localities at Batallones (MN10) (Madrid, Spain). All of it belongs to a single species, which differs from the other known species of the genus and a new taxon, Hispanomys moralesi sp. nov., is created for it. The samples from the various localities show differences interpreted as being the result of slight age disparities amongst the different sites. Although they were previously thought to be coeval, Batallones 10 is probably older than Batallones 1, which is possibly older than Batallones 3. Hispanomys moralesi sp. nov. is characterized by several morphological features such as the lack of cingula and mesolophs, the presence of well-developed ectolophs, four- or five-rooted M1, short or absent mesolophids, and reduced and simplified M3. Hispanomys moralesi sp. nov. is a relatively derived species, the evolutionary stage of which is comparable to those of other members of the genus from the Upper Vallesian.This study has been partly funded by research projects CGL2008-05813-CO2-01, (MICIIN, Spanish Government), CGL2007-65208, CGL2008-04200/BTE and Research Group UCM 910607. R. L. A. is currently supported by the Ramón y Cajal Program. I. G.-P. has a postdoctoral contract with the Spanish Foundation for Science and Technology (FECYT) and the Spanish Ministry of Science and Innovation.Peer reviewe

New species of Hispanomys (Rodentia, Cricetodontinae) from the upper miocene of batallones (Madrid, Spain)

Material of Hispanomys (Rodentia, Cricetodontinae) is described from various localities at Batallones (MN10) (Madrid, Spain). All of it belongs to a single species, which differs from the other known species of the genus and a new taxon, Hispanomys moralesi sp. nov., is created for it. The samples from the various localities show differences interpreted as being the result of slight age disparities amongst the different sites. Although they were previously thought to be coeval, Batallones 10 is probably older than Batallones 1, which is possibly older than Batallones 3. Hispanomys moralesi sp. nov. is characterized by several morphological features such as the lack of cingula and mesolophs, the presence of well-developed ectolophs, four- or five-rooted M1, short or absent mesolophids, and reduced and simplified M3. Hispanomys moralesi sp. nov. is a relatively derived species, the evolutionary stage of which is comparable to those of other members of the genus from the Upper Vallesian.This study has been partly funded by research projects CGL2008-05813-CO2-01, (MICIIN, Spanish Government), CGL2007-65208, CGL2008-04200/BTE and Research Group UCM 910607. R. L. A. is currently supported by the Ramón y Cajal Program. I. G.-P. has a postdoctoral contract with the Spanish Foundation for Science and Technology (FECYT) and the Spanish Ministry of Science and Innovation.Peer reviewe

Are the Rhizomyinae and the Spalacinae closely related? Contradistinctive conclusions between genetics and palaeontology

The reconstruction of the evolutionary history of the Rhizomyinae and the Spalacinae based on the fossil record strongly suggests that these do not share the same murid ancestor and developed separately since the early Oligocene. This conclusion is supported by the difference in evolutionary dynamics between these groups during the Miocene and Pliocene. Molecular genetic studies of extant representatives of the Rhizomyinae, Spalacinae and Myospalacinae, however, suggest that these subfamilies share similarities that distinguish them from all other Muridae. As a result, geneticists unite these subfamilies into the family Spalacidae and consider the Spalacidae and the Muridae to be sister lineages. Until the conflict between the two disciplines is resolved we prefer to maintain the Rhizomyinae and the Spalacinae as two subfamilies within the family Muridae (superfamily Muroidea)