Sigmodontinae

See text The Sigmodontinae is one of the most diverse groups of mammals. It includes at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. They are distributed throughout the New World, but are predominantly South American. The sigmodontines inhabit many of the same ecological niches that the Murinae inhabit in the Old World.

The Sigmodontinae are divided into a number of tribes and genera:

Subfamily Sigmodontinae
- Tribe Abrothrichini
- Tribe Phyllotini
- Tribe Oryzomyini
- Tribe Thomasomyini
- Tribe Akodontini
- Tribe Ichthyomyini

The "Thomasomyini " from the Atlantic Forest of Brazil are generally thought to be not especially related to the "real" Thomasomyini from the northern Andes and Amazonia. The genera Wiedomys and Sigmodon are generally placed in their own tribe, and the "phyllotines" Irenomys , Punomys , Euneomys , and Reithrodon are considered incertae sedis.