Nesoromys Thomas 1922

Nesoromys Thomas 1922, Ann. Mag. Nat. Hist., ser. 9, 9: 263.

Type Species: Stenomys ceramicus Thomas 1920

Species and subspecies: 1 species:

Species Nesoromys ceramicus (Thomas 1920)

Discussion: Rattus Division. Rümmler (1938) united Nesoromys with Stenomys explaining only that the differences between it and other species in Stenomys was insufficient to recognize a separate genus for ceramicus; he considered ceramicus to represent Stenomys, a group primarily New Guinean in distribution, on Seram. The species, however, exhibits a combination of primitive and highly derived traits not seen in other species of Stenomys or Rattus (Aplin et al., 2003 b; Misonne, 1969). While ceramicus does bear a superficial resemblance to New Guinea R. niobe (which Rümmler placed in Stenomys) in body size, pelage coloration and texture, and general cranial conformation, it differs considerably from any other endemics in the Indomaylan, Moluccan, and Australia-New Guinea regions by its combination of very specialized bony palate (extremely broad and projecting way beyond posterior margins of molar rows), short incisive foramina that end well anterior to molar rows, and shallow pterygoid fossae, prompting Ellerman (1941:258) to admonish that "... until intermediate forms are discovered between this genus and Rattus in characters of the palate, it must stand as a very distinct genus." We agree and retain the genus (as did Ellerman [1949 a], Laurie and Hill [1954], Misonne [1969], and Simpson [1945]) with its morphologically distinctive species until a relationship is demonstrated otherwise by phylogenetic analyses employing morphology and DNA sequences from a broad range of Indo-Australian murines.