Mammals are not especially diverse. Roughly 6,800 mammal species are known to exist, compared with about 8,800 species of amphibian, 11,000 species of bird and 12,500 of reptile. Yet when most people ...

Until recently, this lineage was thought to exist only in eastern Australia. But on the huge, biologically diverse island of New Guinea, there was no sign of its existence. Scientists presumed it had ...