Millardia Thomas 1911

Millardia Thomas 1911, J. Bombay Nat. Hist. Soc., 20: 998.

Type Species: Golunda meltada Gray 1837

Synonyms: Grypomys Thomas 1911; Guyia Thomas 1917; Millardomys Sody 1941 .

Species and subspecies: 4 species:

Species Millardia gleadowi (Murray 1885)

Species Millardia kathleenae Thomas 1914

Species Millardia kondana Mishra and Dhanda 1975

Species Millardia meltada (Gray 1837)

Discussion: Millardia Division. Listed as a genus by Ellerman in 1941, but later as a subgenus of Rattus (Ellerman, 1961) . By 1969, Millardia was again treated as a genus and thought to be closely related to the Indian Cremnomys (Misonne, 1969) . Subsequent analyses of morphological features and particularly chromosomal traits have demonstrated the great phylogenetic distance between Rattus and Millardia (Gadi and Sharma, 1983; Mishra and Dhandra, 1975; Raman and Sharma, 1977). Cytogenetic analyses resulted in a phylogenetic hypothesis isolating Millardia and Cremnomys from other Asian genera (Gadi and Sharma, 1983), which is corroborated by analyses of mitochondrial sequences (DNA cytochrome b, 12S and 16S rRNA gene fragments), in which Ducroz et al. (2001:200) found no evidence of close relationship between Millardia and African arvicanthines (contradicting results from DNA/DNA hybridization; Chevret et al., 1994) or between Millardia and any murine genera tested; Millardia was basal in nearly all their phylogenetic reconstructions. This position is supported by albumin immunology suggesting that " Millardia appears to be a monogeneric clade arising early in the history of the murines" (Watts and Baverstock, 1995 b). That ancient lineage also contains Cremnomys, Madromys, and probably Diomys, all Indian subcontinent endemics. An affinity with the African Praomys has been suggested (Corbet and Hill, 1992; Misonne, 1969) but not substantiated by phylogenetic analyses of morphological or molecular traits (e. g., Lecompte, 2003). Agrawal (2000) characterized Millardia and reviewed its taxonomic history; also reviewed by Corbet and Hill (1992). Enamel microstructure of incisors and molars and its significance presented by Patnaik (2002).

Two species of Millardia, until 1982 thought to be strictly an Asian genus, were recorded from the late Pliocene of Ethiopia (Sabatier, 1982). One of them was reidentified as an Acomys (Denys, 1990 a), identity of the other needs to be reevaluated, but to us its molar occlusal patterns also resemble those of Acomys . Outside of the supposed African record, evolutionary history of Millardia (identified as cf Millardia or M. cf. meltada) is documented from early Pliocene to late Pleistocene strata only on the Indian subcontinent (NW India and N Pakistan; Gupta and Prasad, 2001; Musser, 1987 b; Patnaik, 1995, 1997, 2001).