The following paper was presented at the International Symposium on the Biogeography of Madagascar held in Paris 26-28 September 1995. The printed version of the paper was published in the Symposium volume (Schatz, G.E. 1996. Malagasy/Indo-Australo-Malesian phytogeographic connections. In: W.R. Lourenšo (ed.), Biogeography of Madagascar. Editions ORSTOM, Paris).

ABSTRACT

Despite the continuous close proximity of Madagascar to Africa since its separation from the continent ca. 165 MYA, the Malagasy flora exhibits a remarkably high affinity with the Indo- autralo-malesian floras far to the east. Such phytogeographic connections are especially prevalent among eastern humid forest taxa, and represent both ancient vicariance that has resulted in relictual (Cretaceous) Gondwanan disjunctions, as well as continuous dispersal events across the Indian Ocean. Three major patterns of dispersal/vicariance modality can be identified: 1) Cretaceous dispersal to Madagascar with ensuing distributions from India (and/or South Africa) across Antarctica to South America and Australo-E. Malesia during the time of the initial radiation of the angiosperms; 2) Eocene-Oligocene (and continuing to the present) dispersal to Madagascar (and Africa) from Laurasia and W. Malesia via India (pre- and post-collision with Asia) along "Lemurian Stepping-stones" in the western Indian Ocean; and 3) continuous (and recent) long distance dispersal (LDD) to Madagascar as a function of the prevailing easterly winds and Indian Ocean currents.

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