Gondwanaland Connections in the Terrestrial Molluscs of Africa and Australia

Summary

Africa and Australia share only two Gondwanaland families, the Rhytididae and Charopidae. In a bicontinental pattern the former are rather diverse in the Australian Region and only sparsely represented in Africa; the latter are of somewhat comparable diversity in both continents, but appear to be very diverse elsewhere (e.g., New Zealand), while exhibiting a tri continental pattern. The evolutionary success of these and other Gondwanaland families has been markedly po o r in Africa as compared to that in the other remnants of Gondwanaland. This may be explained by the island history of Africa and its subsequent contact with Eurasia (Laurasia); once t his was established the vigorous and d iverse Eurasian elements started invading Africa from the north replacing the Gondwanaland -elements or frus trating their northward dispersal. Both Australia and South America remained comparatively much more isolated, so that the Gondwanaland elements retain ed or established a comparatively much more dominant position.