Chelemys Thomas 1903

Chelemys Thomas 1903, Ann. Mag. Nat. Hist., ser. 7, 12: 242.

Type Species: Akodon megalonyx Waterhouse 1845

Species and subspecies: 3 species:

Species Chelemys delfini Cabrera 1905

Species Chelemys macronyx (Thomas 1894)

Species Chelemys megalonyx (Waterhouse 1844)

Discussion: Akodontini (S Andean clade). Named as a subgenus of Akodon, later ranked as a genus (Gyldenstolpe, 1932; Reig, 1987; Thomas, 1927) or consolidated under Notiomys, together with Geoxus (Cabrera, 1961; Ellerman, 1941; Osgood, 1925, 1943). Trees derived from cytochrome b data consistently disclose close kinship among these three long-clawed, semifossorial taxa (and Pearsonomys — Smith and Patton, 1999), a finding that is cladistically harmonious with their monophyly as perceived by Osgood (1925), who arranged the species under the one genus Notiomys . However, morphological differentiation among them is pronounced, as emphasized by Thomas (1927), Gyldenstolpe (1932), Pearson (1984), and Reig (1987). The latter two authors enumerated diagnostic traits and amplified their morphological definition as genera; also see Patterson (1992 b) for other morphological and morphometric comparisons and a key to the genera and species of long-clawed akodonts. Chelemys angustus Thomas, 1927, is based on a specimen of Akodon longipilis according to Pearson (1984).