When an Australian scientist uncovered an ancient-looking placoderm skull in the 1960s, he thought he'd cracked the code on an evolutionary mystery. This so-called 'platypus fish,' scientists had ...

You might think you know why the platypus is a bizarre beast. Maybe you know that it lays eggs, that the males have venomous spurs on their ankles, and that it can sense electricity with its bill. But ...