Lemurs are a type of prosimian, which means they are primates that evolved before monkeys and apes. They are more primitive than their cousins but share certain characteristics. Found in only one area on Earth—Madagascar and the nearby Comoro Islands—lemurs are considered the world’s most endangered group of mammals. Today there are over 100 lemur species. Their lemur-like primate ancestor is thought to have rafted over to Madagascar from Africa about 60 million years ago. With no competition from other primates and little predation, the original lemurs evolved to fill a large number of varying niches on the island.