A senior palaeontologist from the Queensland Museum says a mine west of Mackay, in the state's north, is home to a unique fossil site.
Dr Scott Hocknull has been digging at the South Walker Mine, near Nebo, for the past three years, after an ancient billabong was discovered.
He says they have discovered many different species that were likely to have been eaten by giant crocodiles.
"This is the time of the megafauna, so we're only talking 50 to 30,000 years ago and potentially when humans arrived," he said.
"You're slowly working your way through the mud and the silt and uncovering piece by piece these bones.
"We're finding everything from the tiniest little insect fossil and leaf fossil to the bones of diprotodon, which is like a two-and-a-half tonne wombat.
Dr Hocknull says it is unique to have such a large number of fossils in north Queensland.
"Traditionally the tropics have been a very hard place to find fossils and that's because when a skeleton is exposed to the air and humidity and the heat, it disintegrates very quickly but because of the crocodile action," he said.
"The crocodiles have been feeding on these animals - they've been taken from living to dead and fossilised very quickly.
"It's a unique snapshot that isn't recorded pretty much anywhere in northern Australia."