Around 80% of Madagascar's wildlife is found nowhere else as a result of the island's strange geological history. Once part of the Gondwana supercontinent, Madagascar lost contact with Africa (160 million years ago), then with Antarctica, Australia and finally India. Many of its endemic species, such as the elephant bird, stuck with the island for the entire journey and gradually evolved into forms that differed from their cousins on other continents. But while Australia and India drifted far from Africa, Madagascar remained close - only 400km of sea separates them today. Animals and seeds swept out to sea from Tanzania's and Mozambique's rivers could conceivably make it across to the island as happened with the ancestors of Madagascar's lemurs around 54 million years ago, and its baobab trees 20Ma.

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