Integrative taxonomic revision of endemic dwarf shrews from the Ethiopian Highlands

The biodiversity of the Ethiopian Highlands features a significant level of endemism. Among its diverse fauna, the genus Crocidura (Soricidae), with many cryptic species, remains poorly documented, particularly for species of minute size. This study describes a newly discovered minute shrew – one of the smallest mammals worldwide – and addresses the taxonomy of the so-called ‘Afromontane clade’ of Crocidura in Ethiopia. We combined extensive field sampling of recent and historical specimens with advanced genetic analyses (genome skimming, Illumina sequencing, and cytb phylogenetics) and morphological examination (external and craniodental) to delineate the new species and address taxonomic affinities among other minute Crocidura from Ethiopia. One of our newly collected forms represents a distinct genetic lineage, corresponding with unique physical characteristics such as tail length and cranial features. Its discovery highlights the rich, yet still incompletely understood, mammalian diversity in the Ethiopian Highlands and underscores the importance of integrating morphological and molecular data in taxonomic studies.