Phylogenetic position of Leimacomys, an enigmatic African rodent genus, reconsidered in the light of morphological and its first genetic data

The family Muridae represents the most diversified clade of rodents. Their remarkable convergent morphology has challenged taxonomists to establish a robust classification. Thanks to molecular phylogenetic analyses, five subfamilies of murid rodents are hereby defined: Lophiomyinae, Deomyinae, Gerbillinae, Leimacomyinae and Murinae. As the single representative of the subfamily Leimacomyinae, Leimacomys buettneri is known only by the first two specimens collected in 1890. It was classified either as belonging to the Dendromurinae (Nesomyidae), or recently placed in its own subfamily Leimacomyinae (Muridae). Here we present the first molecular genetic analysis of the holotype and the paratype of Leimacomys by genomic skimming and assembly of the mitogenomes. It confirms that Leimacomys belongs to the Muridae as a sister to all extant Deomyinae. As a result, we have re-examined the morphology of type specimens and compared them with deomyine taxa as well as Miocene fossil rodents that are considered as murid-like ancestors. This allows us to propose an updated scenario for the origins of the murid lineages. In the light of our novel genetic and morphological data, we propose to keep the subfamily Leimacomyinae, represented by the monotypic Leimacomys, within the family Muridae.