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The southern part of China and northern part of Indochina Peninsula is one of the hot-spots of biodiversity (e.g., Cincotta et al. 2000; Cox and Moore 2005). In this area, there are many endemic mammalian species, such as giant panda Ailuropoda melanoleuca, saola Pseudoryx nghetinhensis, Tonkin snub-nosed monkey Rhinopithecus avunculus, Inornate squirrel Callosciurus inornatus, black-eared red-backed vole Eothenomys olitor, and Yunnan hare Lepus comus (e.g., Wilson and Reeder 2005). Meijaard and Groves (2006) also found high mammalian diversity in the east side of the Mekong River including this area. Therefore, this area would be very important for the speciation and diversity of mammals in Asia. Giant flying squirrels (genus Petaurista) are widely distributed throughout South and Southeast Asia and in southern China, Taiwan, and Japan (Corbet and Hill 1992; Wilson and Reeder 2005). At present, they are split into eight species: P. alborufus, P. elegans, P. leucogenys, P. magnificus, P. nobilis, P. petaurista, P. philippensis, and P. xanthotis (Wilson and Reeder 2005). In each species, many variations and synonyms are reported (e.g., Ellerman and Morrison-Scott 1951; Corbet and Hill 1992; Wilson and Reeder 2005). In the southern China and northern Indochina Peninsula, three giant flying squirrel species (P. alborufus, P. petaurista, and P. philippensis) are commonly found (Lekagul and McNeely 1988; Corbet and Hill 1992). Based on genetic variations and morphological characteristics, in southern China, Yu et al. (2006) recognized as distinct two additional species (P. hainana from Hainan Island and P. yunanensis from Yunnan), although these species had been classified as P. philippensis by Wilson and Reeder (2005). Thus, this area may also be a biodiversity hotspot for Petaurista species. Based on molecular data, Oshida et al. (2004a) proposed that Petaurista might have some geographical evolutionary units or groups. Southern China and the northern Indochina Peninsula may be the source of one geographical evolutionary unit of Petaurista. To explore this conjecture further, we examined the phylogenetic position of two Petaurista species collected from northern Vietnam, the Indian giant flying squirrel (P. philippensis) and the spotted giant flying squirrel (P. elegans). These two forms were phylogenetically compared with those from southern China and the island of Sumatra. Here, we discuss the phylogenetic relationships of P. philippensis and P. elegans. |
