Saturday, July 9, 2016

Animals populating Madagascar by rafting there

How did lemurs, flying foxes, and narrow striped mongooses get to the large, isolated island of Madagascar sometime after 65,000,000 years ago when the dinosaurs went extinct? The island of Madagascar and the continent of Africa have been separate for 120 million years, but ancestors of Madagascar's unique collection of lemurs, carnivores, tenrecs, rodents, and bats only arrived 60-20 million years ago. With no land connection, how did they migrate 300 miles of ocean to the island? On natural rafts. According to research from Perdue and Hong Kong university, computer simulations of ancient ocean currents showed the flow at that time could have delivered the animals on logs blown to sea by storms. The current flows South and West today, but at the time animals arrived on Madagascar (and the Comoros), the current moved quickly Eastward toward the island. Enough animals could have made the trip through the vast depths of geologic time to begin an evolutionary course leading to the island's current animal population; One found nowhere else on the planet. I've 1st known about this from the Be The Creature episode about lemurs. The bats and Pinipids of Madagascar may have lived there earlier before the mammals got to Madagascar. There is an average of lemurs arriving there 60-50 million years ago, tenrecs about 42-25 million years ago, rodents about 24-20 million years ago, and carnivores about 26-19 million years ago. There are 100 lemur species, 30 tenrec species, 30 rodent species, 11 carnivore species, and 69 bat species.

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