Hatcher has also found caves with primitive boomerangs that he believes were used for hunting bats. But again, megafauna and humans aren't found in the same places—except in a tantalizing few.

Who or what snuffed out the mammoths and other megafauna 13,000 years ago? It takes a certain kind of person to take on this question as his or her life's work. You have to be itching to know the ...

A long, long time ago, marsupials the size of small trucks, 2-meter-tall "thunder birds" and 5-meter-long venomous lizards roamed Australia. These animals—and more—were Australia's megafauna.