SYDNEY, Australia — Before there were cuddly koalas, hoards of flesh-eating kangaroos, "demon ducks," and marsupial lions roamed Australia's Outback, according to recent fossil discoveries by paleontologists. A team of researchers from the University of New South Wales working in the eastern state of Queensland made the discoveries in three new fossil deposits during a recent two-week dig. Many of the fossils are older than 24 million years; one of the deposits is thought to contain fossils up to 500 million years old, according to Prof. Mike Archer, the university's dean of science. A saber-toothed kangaroo and a giant 10-foot-tall,...