Scientists hailed Tuesday a 47-million-year-old fossil of an ancient "small cat"-sized primate as a possible common ancestor of monkeys, primates and humans. Scientists say the fossil, dubbed “Ida,” is a transitional species, living around the time the primate lineage split into two groups: A line that would eventually produce humans, primates and monkeys, and another that would give rise to lemurs and other primates. The fossil was formally named Darwinius masillae, in honor of the anniversary of Charles Darwin’s 200th birthday
