Nesoryzomys Heller 1904

The genus Nesoryzomys comprises five species, N. darwini (Osgood 1929), N. fernandinae (Hutterer & Hirsch 1979), N. indefessus (Thomas 1899), N. narboroughi (Heller 1904), and N. swarthi (Orr 1938) . These species were restricted to the Galápagos Islands, Ecuador, with recent specimens known from only four of the major islands in the archipelago: Isla Baltra, Isla Fernandina, Isla Santa Cruz, and Isla Santiago. One undescribed species known from fragmentary subfossil remains, have been reported from Isla Isabela and Isla Rábida. Of the five species, two were now considered extinct, N. darwini and N. indefessus (Steadman & Zousmer 1988; Prado & Percequillo 2013; Dowler 2015). There was cytogenetic information available only for N. narboroughi .