亚洲高海拔锄足蟾的属间亲缘关系、分化及其与青藏高原形成的关系

本文在研究高海拔锄足蟾的属间分类及分布规律的基础上,对所属的齿蟾属Oreolalax、齿突蟾属Scutiger的齿突蟾亚属Scutiger,(Scutiger)和猫眼蟾亚属Scutiger(Aelurophryne)的成体外形和骨骼、蝌蚪的形态以及核型等24个性状进行综合分析,同时探讨了属间亲缘关系。结果表明:齿蟾属较原始,齿突蟾属较特化,它们可能起源于共同的祖先——原始齿蟾。在齿突蟾属中猫眼蟾亚属比齿突蟾亚属更为特化,后者与齿蟾属的亲缘关系相对较近。它们的分化与青藏高原的抬开有密切关系。

INTERGENERIC RELATIONSHIPS AND DIVERSIFICATION OF THE HIGH-ALTITUDE PELOBATID TOADS IN ASIA AND THEIR RELATION WITH THE FORMATION OF QINGHAI-XIZ- ANG PLATEAU (AMPHIBIA:PELABATIDAE)

The present paper indicates that Oreolalax is comparatively primitive with more plesiomo-rphies, whereas Scutiger is rather specialized with more apomorphies, Probably both of them were evolved commonly from primitive oreolalaxes. In Sciaiger, the characters of subgenus S. (Aelurophryne) are more specialized than those of S. (Scutiger) which is more closely related to Oreolalax.According to the differences in the characters, geographical distributions, and ecological adaptation of the high-altitude pelobatid toads, it is considered that the diversification of primitive oreolalaxes and the formation of the different groups of high-altitude pelobatid toads are closely associated with the dramatically environmental change induced by violent upheaval of Qinghai-Xizang (Tibet) plateau since the middle of Pleistocene. The primitive oreolalaxes originally living there, gradually evolved and developed into the Scuiiger adapted to the harsh cold conditions of high plateau. In the meantime, Scutiger developed into two branches with different habits, one branch being S. (Scutiger) with a terrestrial habits and the other S. (Aelurophryne) with a habit close to aquatic life.Furtheremore, the environment of the Hengduan Mountains was not much changed during the period of Pleistocene. Thus the primitive oreolalaxes evolved rather slowly. In this way many primitive features were preserved in modern Oreolalax.