Madagascar's mammals sailed to island

Isolated Madagascar, with it's 100 or so species of weird and wonderful mammals, may have only aquired them after seperating from the main land. New research points to the four groups of mammals on the island coming from four individual ancestors that floated over on rafts of plantation. Both the carnivores and the lemurs are not primitive enough to justify assuming they seperated with the island, over 80 million years ago, and both groups point to one ancestor each. The genetic research that has been conducted on them hasn't been conducted on the other two mammalian groups, tenrecs and rodents, but scientist believe they probably arrived the same way, and Madagascar started off as a lone refuge of reptiles and birds.