SCIENCES, TECHNOLOGIES ET DEVELOPPEMENT Revue scientifique de l’Université de Douala BP 24157 Douala – Cameroun Tél. : (237) 33-40-75-69 Fax : (237) 33-40-42-91 E-mail : [email protected] ISSN 1029 - 2225 Phylogeny of Arvicanthine rodents (Muridae: Murinae): a reassessment of the status and relationships of the endemic Mount Oku Rat, Lamottemys okuensis Petter, 1986 with biogeographical implications Alain Didier Missoup 1&2 , Violaine Nicolas 2, Charles Félix Bilong Bilong 3, Arnaud Couloux 4, Christiane Denys 2. 1Department of Animal Biology Organisms, Faculty of Science, the University of Douala, PO Box: 24157 Douala, Cameroon . 2UMR 7205 : Origine, Structure et Evolution de la Biodiversité, Département Systématique et Evolution, Muséum National d’Histoire Naturelle, CP 51 - 55 rue Buffon, 75005 Paris, France . 3Department of Animal Biology and Physiology, Faculty of Science, the University of Yaoundé I, PO Box: 812 Yaoundé, Cameroon . 4 Genoscope, Centre National de Séquençage, 2, rue Gaston Crémieux, CP5706, 91057 Evry Cedex, France. Corresponding author: [email protected] . Abstract The present study combines molecular (cyt b, IRBP, GHR) and morpho-eco-ethological phylogenies to test the status and to infer phylogenetic relationships of the enigmatic Mount Oku Rat, Lamottemys okuensis Petter, 1986. Known by a few number of specimens and restricted to an area that is continuously declining in the extent and quality of habitat, Lamottemys is listed as endangered in the “IUCN” Red List. Based solely on ecological and morphological data, two hypotheses of relationship were previously formulated, both suggesting an affinity to Arvicanthine rodents. Our taxonomic sampling includes 17 of the 18 potential members of the Arvicanthini tribe. Based on tree topologies and divergence time estimates we tackle the question of the historical biogeography of the tribe with an emphasis on the diversification of L. okuensis . Almost all our molecular data strongly support the monophyly of Arvicanthini and suggest the inclusion of Lamottemys within the tribe. In this rodent lineage, the genus is found within the Arvicanthis division with the following genera: Arvicanthis , Desmomys , Lemniscomys , Mylomys , Pelomys and Rhabdomys . A close relationship with the Ethiopian endemic genus Desmomys appears as the most parsimonious result. Our data confirm the inclusion of Dephomys and Thallomys , also tested here, within the Arvicanthini tribe. Like other african murine lineages, Arvicanthine rodents probably diverged from a basal lineage that spread from Asia. In Pliocene, the rifting activity resulting in the elevation of volcanic highlands in East Africa and in the CVL probably explain the diversification of Desmomys and Lamottemys in allopatry following the montane forest refuge speciation model. It would however be necessary for a better understanding of such ancient divergent event to obtain more information at the fossil record. Keywords: Arvicanthini, forest refuge speciation model, Lamottemys okuensis, molecular phylogeny, monophyly, morpho- eco-ethological phylogeny. ISSN 1029 –2225©2014 Sciences, Technologies et Développement os .