The Australian island Tasmania is home to two species of millipedes. These insects only ever meet on a tiny, 300 feet wide patch of land running right down the island. It's a bizarre arrangement, and it has biologists completely baffled.
Many of the creatures that lived in the seas half a billion years ago were far too soft to leave behind many fossils. But their footprints remain, and one of the most striking finds is a giant, predatory sea millipede.