Madromys Sody 1941

Madromys Sody 1941, Treubia, 18 (part 2): 258.

Type Species: Mus blanfordi Thomas 1881

Species and subspecies: 1 species:

Species Madromys blanfordi (Thomas 1881)

Discussion: Millardia Division. After being named a species of Mus, blanfordi was transferred to Rattus and finally to Cremnomys (see comments in following account). To Ellerman (1961:605), blanfordi was a Rattus in subgenus Rattus, but "an aberrant species... it stands rather well apart from typical Rattus, and is probably allied to Cremnomys ." Misonne (1969:126) studied dental traits and included blanfordi in Cremnomys, but noted that "it could be made as well a genus on its own." Corbet and Hill (1992:349) acknowledged that "The inclusion of blanfordi in Cremnomys is supported by data on chromosomes... but is nevertheless very dubious." The extraction of blanfordi from Cremnomys was also supported by Agrawal (2000), who suggested that " blanfordi may be given an independent status as a genus equivalent to Millardia, Cremnomys, and Rattus ." We agree. Unfortunately, Sody diagnosed Madromys only by its three pairs of mammae, a trait also characteristic of Cremnomys and some other tropical Asian murines. However, blanfordi differs from all species of Cremnomys by a suite of characters. Among them are its much larger body size; tail that is brown for proximal two-thirds and all white distally, well-haired and tufted at the tip (monocolor or dark brown above and mottled below in Cremnomys); longer braincase relative to rostrum, its dorsal outline more like an elongate triangle rather than vase-shaped; much wider zygomatic plate relative to cranial size, with deeper zygomatic notch and more pronounced, projecting anterodorsal shoulder; very large, globular and inflated bullae (small and uninflated in Cremnomys); and the molar occlusal traits described by Misonne (1969:126); these contrasts are based upon our study of specimens at AMNH, BMNH, and FMNH, and most holotypes representing taxa in Cremnomys . Among Indomalayan murines, Madromys is phylogenetically closest to Cremnomys, Millardia, and Diomys and unrelated to Rattus (based upon morphology and chromosomal data). Fossils identified as morphologically similar to M. blanfordi come from late Pliocene Siwalik sediments in NW India, and the species may have ancestral roots in the late Miocene Progonomys complex of N India and N Pakistan (Patnaik, 1997).