Dating of ancient human teeth discovered in a Sumatran cave site suggests modern humans were in Southeast Asia 20,000 years earlier than previously thought.

The international research, led by Dr Kira Westaway from Macquarie University and published in Nature, has pushed back the timing of when humans first left Africa, their arrival in Southeast Asia, and the first time they lived in rainforests.

This evidence of humans living in the Sumatran rainforest more than 63,000 years ago also suggests they could have made the crossing to the Australian continent even earlier than the accepted 50,000 to 60,000 years ago.

The site in western Sumatra called Lida Ajer contains fossils of two human teeth, along with rainforest animal fossils. It was originally excavated by Dutch palaeoanthropologist Eugene Dubois in the late 1880s, and revisited a hundred years later by Jon de Vos and Randy Skelton.

But until now, the significance and validity of these human remains had not been widely accepted.

“This cave has been shrouded in doubt since it was first excavated,” Kira says.

Kira’s team dated the sediment around the fossils, the overlying and underlying rock deposits in the cave, and associated mammal teeth.

“We employed a range of dating techniques from different institutions to establish a robust chronology that would, after 120 years, finally put an end to the uncertainty associated with the age and significance of these teeth.”

Other Australian universities involved include the Australian National University, the University of Queensland, the University of Wollongong, Griffith University and Southern Cross University.

Banner image credit: Chris Stacey