Science fiction movies about prehistoric times are always showing giant lizards attacking humans, and the humans are fighting them away.  It has always been thought unlikely that the two species ever co-existed until now, according to an article on naturworldreport.com.

Scientists have known for years that giant lizards roamed the outback of Australia, but it was thought the massive beasts died out long before humans began to settle the territory.

A recent discovery of a bone that may be from one of the giant lizards was dated using radiocarbon and uranium thorium techniques, and was found to be about 5o,000 years old.  The scientists are not completely sure which species of lizard the bone is from as yet, but they suspect it came from a Megalania Prisca, a species that could have measured as long as 15 feet.

If correct, the dating means the lizards were still roaming the country when humans first began to settle there.  Given the size of the lizards, it is believed they could hunt and kill large mammals for food, making humans possible prey.

However, some scientists are thinking the opposite may be the case.  They believe the arrival of humans, with organized hunting skills and primitive tools for weapons, may have hunted the giant lizards into extinction.

Currently, the largest lizard living on the continent is a monitor lizard called perentie, which can measure up to six feet long.  These large lizards are not known for attacking humans, rather avoiding contact when confronted.  They prefer to dine on smaller mammals, like rats and rabbits instead.

The researchers say the bone could possibly be from a komodo dragon, which has been known to grow up to 10 feet in length.  The komodo is only found on a number of small islands in Indonesia at this time, but could have lived in Australia in the past.

Australia is known for its large animals, including a procoptodon, which was a kangaroo that stood almost 7 feet tall.