干旱区生态环境知识资源中心

An analysis of biogeographical relationships of various taxa (mainly Vertebrata, Arthropoda and Gasteropoda) representative of the Southern Malagasy fauna is difficult due to the dry local climactic environment, the originality of the vegetation and, for certain taxa, gaps in current inventories. Recognizing these limitations, one can note that the Southern Malagasy fauna includes: (1) taxa originating through geographical vicariance of groups that occur in all parts of the island; and (2) original taxa, absent or represented by only a few members outside the sub-arid area, which include some relict, isolated monospecific genera as well as some speciose genera typical of the Southern part of Madagscar that have sometimes been able to colonize other parts of the island. Most of these endemic taxa are ancient and of Gondwanan affinity.