The 27 species in the genus Marmosa are relatively small Neotropical members of the family Didelphidae. This genus is one of three that are known as mouse opossums. The others are Thylamys (the "fat-tailed mouse opossums") and Tlacuatzin, the grayish mouse opossum. Members of the genus Marmosops used to be called "slender mouse opossums", but are now just called "slender opossums". The thirteen members of the Marmosa subgenus Micoureus, known as woolly mouse opossums, were formerly considered to be a separate genus, but were moved into Marmosa in 2009. Based on a comparison of sequences of one mitochondrial and three nuclear genes, three new subgenera, Eomarmosa, Exulomarmosa and Stegomarmosa, were recognized by Voss et al. in 2014. Eomarmosa and Exulomarmosa, as well as Marmosa and Micoureus, are thought to be sister taxa, while Stegomarmosa is viewed as sister to Marmosa plus Micoureus. Exulomarmosa is a mostly trans-Andean (west of the Andes) clade. Subgenus Eomarmosa Voss, Gutierrez, Solari, Rossi & Jansa 2014 Marmosa rubra Tate 1931 Subgenus Exulomarmosa Voss, Gutierrez, Solari, Rossi & Jansa 2014 Marmosa isthmica Marmosa mexicana Merriam 1897 Marmosa robinsoni Bangs 1898 Marmosa simonsi Marmosa xerophila Handley & Gordon 1979 Marmosa zeledoni Subgenus Marmosa Gray 1821 Marmosa macrotarsus Marmosa murina (Linnaeus 1758) Marmosa tyleriana Tate 1931 Marmosa waterhousei Subgenus Micoureus Lesson 1842 Marmosa alstoni Marmosa constantiae Marmosa demerarae Marmosa germana Marmosa paraguayana Marmosa jansae Marmosa limae Marmosa meridae Marmosa parda Marmosa perplexa Marmosa phaea Marmosa rapposa Marmosa regina Marmosa rutteri Marmosa adleri Subgenus Stegomarmosa Pine 1972 Marmosa andersoni Pine 1972 Marmosa lepida (Thomas 1888) References Opossums Marsupial genera Taxa named by John Edward Gray