Geographical Distribution,Origin and Evolution,and Centre of differentiation of High-Altitude Pelobatid Toads in Asia (Amphibia:Pelobatidae)

High-altitude pelobatid toads include twenty-nine species,among them thirteen belong to Oreolalax and mainly appear endemically in eastern Hengduan mountains,whereas the other sixteen species are grouped into Scutiger and chiefly found in Qinghai-Xizang Plateau (Tibet).Scutiger includes two subgenera.The first is Scutiger (Scutiger) consisting of ten species and occurring in Himalayan areas and northern Hengduan mountains,seven of which exist in China while the other three in Burma,Nepal and Kashmir.And the second subgenus is S.(Aelurophryne) consisting of six species and mostly found in the middle and norhtern Hengduan mountains.Five species exist in China and the remaining one species in Burma.The geographical distribution of Scutiger and Oreolalax is divided roughly along Mt.Longmen,Mt.Gajin,Mt.Sheduo,Mt.Gongga and the line of about 28°N of the middle Hengduan mountains,and the distribution of the two genera overlaps in these regions.The high-altitude pelobatid toads generally distribute in an area of 77°to 110°E and 24°-36°N.The species of this group are quite abundant in Hengduan mountain areas.In an area of 90° to 104°E and 24°to 33°N,twenty-three species have been found,making up about 79.3% of the total number of Oreolalax and Scutiger.And eighteen species are endemic,occupying 78.3% of 23 species in Hengduan mountain areas.Hence this area may be considered as the probalbe main place of origin and centre of differentiation and speciation of the high-altitude pelobatid toads in Asia.