Giant marsupials, reptiles and flightless birds that once roamed Australia became extinct about 40,000 years ago, later than had been thought and some 5,000 years after humans arrived, a new study suggests.

Controversy has long surrounded when such creatures became extinct in Australia. New equipment that can date teeth and bones has solved the puzzle, Australian researchers said in the latest issue of the journal Science.

They analyzed surrounding sediments and found that they dated back to 30,000 years ago, contradicting evidence elsewhere in Australia which showed that the animals became extinct far earlier, or at least 40,000 years ago.