Maxomys surifer (Miller 1900)

[Maxomys] surifer (Miller 1900), Proc. Biol. Soc. Wash., 13: 148.

Type Locality: Peninsular Thailand, Trang.

Vernacular Names: Indomalayan Maxomys.

Synonyms: Maxomys anambae (Miller 1900); Maxomys antucus (Lyon 1916); Maxomys aoris (Robinson 1912); Maxomys banacus (Lyon 1916); Maxomys bandahara (Robinson 1921); Maxomys bentincanus (Miller 1903); Maxomys binominatus (Kloss 1915); Maxomys butangensis (Miller 1900); Maxomys carimatae (Miller 1906); Maxomys casensis (Miller 1903); Maxomys catellifer (Miller 1903); Maxomys changensis (Kloss 1916); Maxomys connectens (Kloss 1916); Maxomys domelicus (Miller 1903); Maxomys eclipsis (Kloss 1916); Maxomys finis (Kloss 1916); Maxomys flavidulus (Miller 1900); Maxomys flavigrandis (Kloss 1911); Maxomys grandis (Kloss 1911); Maxomys koratis (Kloss 1919); Maxomys kramis (Kloss 1919); Maxomys kutensis (Kloss 1916); Maxomys leonis (Robinson and Kloss 1911); Maxomys luteolus (Miller 1903); Maxomys mabalus (Lyon 1916); Maxomys manicalis (Robinson and Kloss 1914); Maxomys microdon (Kloss 1908); Maxomys muntia (Chasen 1940); Maxomys natunae (Chasen 1940); Maxomys pelagius (Kloss 1916); Maxomys pemangilis (Robinson 1912); Maxomys perflavus (Lyon 1911); Maxomys pidonis (Chasen 1940); Maxomys pinacus (Lyon 1916); Maxomys puket (Chasen 1940); Maxomys ravus (Robinson and Kloss 1916); Maxomys saturatus (Lyon 1911); Maxomys serutus (Miller 1906); Maxomys siarma (Kloss 1919); Maxomys solaris (Sody 1934); Maxomys spurcus (Robinson and Kloss 1914); Maxomys telibon (Chasen 1940); Maxomys tenebrosus (Kloss 1916); Maxomys ubecus (Lyon 1911); Maxomys umbridorsum (Miller 1903); Maxomys verbeeki (Sody 1930) .

Distribution: Indochina; S Burma, Thailand (J. T. Marshall, Jr., 1977 a; Robinson et al., 1995), Laos, S and SW Cambodia (Elephant Mtns, specimens in FMNH; Cardamom Mtns, A. Smith, in litt., 2002), throughout Vietnam (Dang et al., 1994; Van Peenen et al., 1969; specimens in AMNH and IEBR; including Thom and PhuQuoc Isls off the S coast of Vietnam, see Kuznetsov, 2000), and extreme S Yunnan near Laotian border (specimens in IZAS, D. Lunde, in litt., 2004; Wang, 2003; Wu et al., 1996); and the Sunda Shelf (Peninsular Thailand, Malay Peninsula, Borneo, Sumatra, Java, and many smaller islands); in addition to references cited above, range is generally extracted from Corbet and Hill (1992) and Musser et al. (1979).

Conservation: IUCN – Lower Risk (lc).

Discussion: The only species of Maxomys with a range encompassing Indochinese and Sundaic faunal regions. The two groups of samples differ in morphological features, and the significance of this variation should be determined in a careful systematic revision of the genus. Berylmys bowersii, Chiropodomys gliroides, Leopoldamys sabanus, and L. edwardsi have roughly concordant geographic ranges and demonstrate similar patterns of geographic morphological variation (Musser and Newcomb, 1983; Musser et al., 1979). Virtually every insular sample from the Sunda Shelf has been given a scientific name, but any significance of insular variation has yet to be assessed. Corbet and Hill (1992) detected a geographic pattern in pelage coloration, but whether it is concordant with distribution of morphological and molecular traits has yet to be determined. Phylogenetic analyses of mtDNA cytochrome b sequences by A. J. Gorog et al. (2004) identified six distinct lineages in what is now defined as M. surifer associated with 1) Java, 2) Sumatra, 3) Borneo, 4) the Malay Peninsula, 5) S Vietnam, and 6) NE Vietnam. The Javan and Sumatra lineages formed one clade, which is sister to the Bornean clade, the Malay Peninsula lineage is sister to the Java/Sumatra and Bornean clades, and the two Vietnamese lineages are basal to all those other lineages with the southern Vietnamese cluster siser to the clades from the Malay Peninsula and Sundanese islands. Gorog et al. (2004) suggested that M. surifer evolved on the Indochinese mainland and the vicariance patterns revealed by molecular analyses "... likely have their roots in the Pliocene fragmentation of the Sunda block..." rather than widespread dispersal across the late Pleistocene Sunda Shelf and subsequent isolation with increasing sea levels. The early presence of Maxomys in the Indomalaysian region is supported by late Pliocene to middle Pleistocene fossils of Maxomys and related forms (Chaimanee, 1998; van der Meulen and Musser, 1999).

Comparative spermatozoal morphology documented by Breed and Yong (1986), chromosomal and biochemical data summarized by Chan et al. (1979) in phylogenetic context, and chromosomal data for Vietnam samples reported by Bulatova et al. (1992). Md Nor (1996) recorded its distribution and ecology on the small islands off the tip of N Sabah. Generally a lowland species, M. surifer reaches 1680 m on the slopes of Mt Kinabalu in Sabah (Md Nor, 2001, and references cited therein). Ecological relationships with species of Bandicota, Mus, Rattus, Leopoldamys, and Niviventer in S Yunnan near Laotian border discussed by Wu et al. (1996). Maxomys surifer is the only Maxomys occurring in China (S Yunnan). Wang (2003), however, recognized M. rajah from S Yunnan and M. musschenbroekii from Guizhou Province, but the former is a Sundaic endemic and the latter lives only on Sulawesi (see those accounts). Isolated molars identified as M. surifer have been recovered from late Pliocene to Holocene cave sediments in Thailand (Chaimanee, 1998).