Large vesper mouse

Large vesper mouse
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Cricetidae
Subfamily: Sigmodontinae
Genus: Calomys
Species:
C. callosus
Binomial name
Calomys callosus
Rengger, 1830

The large vesper mouse (Calomys callosus) is a South American rodent species of the family Cricetidae.

It is found in Argentina, Bolivia, Brazil and Paraguay.

Its karyotype has 2n = 50 and FN = 66. It was formerly synonymized with C. expulsus, but the latter has 2n = 66 and FN = 68.

It is particularly notable as the vector of Bolivian hemorrhagic fever.