A new species of Ctenomys (Rodentia, Ctenomyidae) from the pre-Andean regions of Mendoza Province, Argentina.

This article focuses on the taxonomic evaluation and formal description of a new species of subterranean rodent, *Ctenomys miguelchristie* sp. nov., from the genus *Ctenomys* (Rodentia: Hystricomorpha) in southern Mendoza Province, Argentina. Integrating molecular (mitochondrial cytochrome b sequences) and morphological data from recent field collections, the study identifies this species as a distinct, monophyletic lineage within the "magellanicus" clade, genetically and morphologically differentiated from closely related congeners. The new species inhabits arid, mountainous fluvial plains at altitudes between 1,300 and 1,700 meters and represents part of a region where three *Ctenomys* lineages—'magellanicus,' 'maulinus,' and 'mendocinus'—converge, highlighting the area's significance for rodent biodiversity and conservation. The findings underscore ongoing challenges in delimiting species boundaries within *Ctenomys* due to morphological similarity and incomplete sampling, emphasizing the need for continued integrative taxonomic research in Andean and Patagonian habitats.