Otomys jacksoni Thomas 1891 Otomys jacksoni Thomas 1891, Ann. Mag. Nat. Hist., ser. 6, 7: 304. Type Locality: Uganda, crater of Mount Elgon, 13,200 ft. Vernacular Names: Mount Elgon Vlei Rat. Distribution: Restricted to Mount Elgon, ca. 3300-4200 m, Uganda and Kenya. Discussion: Typically considered a subspecies of O. typus subsequent to Bohmann’s (1952) monograph (e.g., Misonne, 1974; Musser and Carleton, 1993). Although their lower incisors do possess two well-defined grooves, as in O. typus, the Mount Elgon populations contrast sharply in their smaller size, dark brown pelage, and M3 with only 7 laminae. Clausnitzer and Kityo (2001) recorded the species (as O. typus) as common in afro-alpine habitats, where it exists sympatrically with O. barbouri.

Published as part of Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Muridae, pp. 1189-1531 in Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore :The Johns Hopkins University Press on page 1527, DOI: 10.5281/zenodo.7316535