Leopoldamys Ellerman 1947

Leopoldamys Ellerman 1947, Proc. Zool. Soc. Lond., 1947-1948 (117): 267.

Type Species: Mus sabanus Thomas 1887

Species and subspecies: 6 species:

Species Leopoldamys ciliatus (Bonhote 1900)

Species Leopoldamys edwardsi (Thomas 1882)

Species Leopoldamys milleti (Robinson and Kloss 1922)

Species Leopoldamys neilli J. T. Marshall, Jr. 1976

Species Leopoldamys sabanus (Thomas 1887)

Species Leopoldamys siporanus (Thomas 1895)

Discussion: Dacnomys Division. Definition and contrasts with Rattus and Niviventer provided by Musser (1981 b), who also reviewed morphological, chromosomal, and distributional characteristics. Additional chromosomal data for Vietnam samples provided by Bulatova et al. (1992). Leopoldamys is dentally similar to Berylmys, Maxomys, and Niviventer . Sperm morphology unites Leopoldamys with Berylmys, Sundamys, and Rattus (Breed and Yong, 1986), but alliance is based on shared spermatozoal form that is likely primitive. Chromosomal traits suggested Leopoldamys is more closely related to Bandicota, Berylmys, Nesokia, Rattus, and Sundamys, than to Lenothrix, Maxomys, or Niviventer (Gadi and Sharma, 1983) . Best estimates of relationships are derived from molecular and morphological sources. Allozymic and morphological data clearly separates Leopoldamys from Rattus (Chan et al., 1979; Musser, 1981 b; Musser and Newcomb, 1983). Cladistic analysis of DNA sequences of LINE-1 elements placed Leopoldamys and Niviventer as sister-genera in a clade separate from that containing Rattus, Berylmys, Bandicota, and Sundamys (members of our Rattus Division), and another clade containing only Maxomys (Verneau et al., 1997, 1998), results also reflected in studies of albumin immunology (Watts and Baverstock, 1994 b), DNA/DNA hybridization assays (Chevret, 1994 [cited in Verneau et al., 1997]; Ruedas and Kirsch, 1997), and generally in cranial and dental traits (Musser and Newcomb, 1983).

Leopoldamys is represented by fossils identified as L. edwardsioides from early Pleistocene cave sediments in the Sichuan-Guizhou where it was replaced at later horizons in the early Pleistocene by L. edwardsi (Zheng, 1993); L. sp. is represented by molars recovered from cave strata in Guangxi Province of S China (Chen et al., 2002). Isolated molars recovered from middle Pleistocene cave sediments in Thailand have been identified as L. sabanus, and teeth from late Pliocene and early Pleistocene horizons were described as L. minutus, a possible ancestor of extant L. edwardsi (Chaimanee, 1998) .