Ndiaye A. auteur aut IRD Hima K. auteur aut IRD Dobigny Gauthier auteur aut IRD Sow A. auteur aut IRD Dalecky Ambroise auteur aut IRD Ba K. auteur aut IRD Thiam M. auteur aut IRD Granjon Laurent auteur aut IRD text journalArticle eng text/pdf born digital access Aridification processes that affected the Sahelian area of West Africa during the last decades have induced significant changes in plant and animal communities of this region. In rodents, the genus Gerbillus characteristic of North African and Asian arid habitats has been affected by this climatic and environmental trends. Several species of this genus showed a southward range expansion in recent years into the Sahelian bioclimatic zone. Recent sampling in several localities of West Africa (Mali, Niger and Senegal) enabled us to collect numerous specimens of small gerbils. An integrative study of these samples using molecular, morphological and cytogenetical methods revealed that many of them were attributable to Gerbillus nancillus, a secretive and poorly known species. Gerbillus nancillus appears characterized by a well differentiated karyotype with 2n = 56 chromosomes, and to represent a unique genetic lineage within this genus. Body and skull measurements of G. nancillus were compared with those of the morphologically similar Gerbillus henleyi, which provided diagnostic clues between them. These new data significantly expand the distribution area of G. nancillus, which now ranges from Sudan in the East to Senegal in the West. G. nancillus is here reported from numerous new localities in Niger and Mali, and for the first time in Senegal, which raises questions about the origin of its presence and the colonization routes it followed to get there. We also show that G. henleyi and G. nancillus are sympatric and apparently often syntopic in the sub-Saharan part of the distribution of G. henleyi. specialized Biogeography Cytochrome b Gerbillus nancillus Karyotype Morphometry Sahel Taxonomy MALI NIGER SENEGAL ZONE SAHELIENNE 080 253 5 430-439 2014 0044-5231 https://www.documentation.ird.fr/hor/fdi:010062374 10.1016/j.jcz.2014.03.004 0044-5231 [F B010062374] https://www.documentation.ird.fr/hor/fdi:010062374 https://www.documentation.ird.fr/intranet/publi/2014/08/010062374.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2014-09-09 2017-08-23 fdi:010062374 fre