Class Mammalia
Order Rodentia
Family Cricetidae
Subfamily Sigmodontinae


Calomys (Bensonomys)—Benson Vesper Mouse // Calomys (Bensonomys) arizonae—Arizona Vesper Mouse // Sigmodon—Cotton Rats

Sigmodontinae—Sigmodontine Mice and Rats

This is primarily a South American subfamily. Two genera (Sigmodon and Oryzomys) reach into the U.S., but only the cotton rats inhabit our region.


Calomys (Bensonomys) sp.—Benson Vesper MicePleistocene distribution of Calomys (Bensonomys) sp.

Synonyms. Bensonomys.

Calomys (Bensonomys) has variously been recognized as a subgenus of Calomys or as a separate genus, Bensonomys. A number of species of Calomys currently occur in South America, but the genus doesn't reach our region. Calomys (Bensonomys) appears to share a common ancestor with Peromyscus. With about a dozen species, Calomys (Bensonomys) is widespread in Hemphillian and Blancan deposits.


Late Blancan: Caballo (Morgan et al. 2011).

Late Blancan/Irvingtonian: Anza-Borrego (Murray 2008).

Literature. Morgan et al. 2011; Murray 2008.


Calomys (Bensonomys) arizonae—Arizona Vesper Mouse (Gidley 1922) Pleistocene regional distribution of Bensonomys arizona

Synonyms. Bensonomys arizonae.


Late Blancan: 111 Ranch (Morgan and White 2005); California Wash (Johnson et al. 1975); Curtis Ranch (Morgan and White 2005); Virden (Morgan et al. 2008: cf.).

Literature. Johnson et al. 1975; Morgan and White 2005; Morgan et al. 2008.


Last Update: 8 Apr 2014